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Carob pulp as raw material for production of the biocontrol agent P. agglomerans PBC-1
Abstract
Large-scale production has been the major obstacle to the success of many biopesticides. The spreading of microbial biocontrol agents against postharvest disease, as a safe and environmentally friendly alternative to synthetic fungicides, is quite dependent on their industrial mass production from low-cost raw materials. Considerable interest has been shown in using agricultural waste products and by-products from food industry as nitrogen and carbon sources. In this work, carob pulp aqueous extracts were used as carbon source in the production of the biocontrol agent Pantoea agglomerans PBC-1. Optimal sugar extraction was achieved at a solid/liquid ratio of 1:10 (w/v), at 25°C, for 1 h. Batch experiments were performed in shake flasks, at different concentrations and in stirred reactors at two initial inoculums concentrations, 10(6) and 10(7) cfu ml(-1). The initial sugar concentration of 5 g l(-1) allowed rapid growth (0.16 h(-1)) and high biomass productivity (0.28 g l(-1) h(-1)) and was chosen as the value for use in stirred reactor experiments. After 22 and 32 h of fermentation the viable population reached was 3.2 × 10(9) and 6.2 × 10(9) cfu ml(-1) in the fermenter inoculated at 10(6) cfu ml(-1) and 2.7 × 10(9) and 6.7 × 10(9) cfu ml(-1) in the bioreactor inoculated at 10(7) cfu ml(-1). A 78% reduction of the pathogen incidence was achieved with PBC-1 at 1 × 10(8) cfu ml(-1), grown in medium with carob extracts, on artificially wounded apples stored after 7 days at 25°C against P. expansum.
... However, the presence of phenolic compounds in the extracts till 2 mg/mL showed no effect on A. succinogenes growth or SA production, even though they are known for anti-microbial properties ( Kang et al., 2008;Campos et al., 2009;Borges et al., 2013). The sugar extraction yield from carob flour was 50% lower than the one reported in literature for raw carobs Manso et al. (2010). One explanation is that the roasting process to which the carob flour is subjected prior to its commercialization, to increase storage shelf life, triggers chemical reactions such as Maillard reac- tion and sugar caramelization, decreasing the sugar content of the carobs (Yousif and Alghzawi, 2000). ...
... The dried kibbles were milled to a fine powder. Sugars extraction was performed by suspending carob powder in distilled water at solid/liquid ratios 1:10 or 2:10 (w/v), depending on the desired sugar concentration of the extracts, and incubated at 25 °C in a rotary shaker at 200 rpm for 1 h ( Carvalho et al., 2014a;Manso et al. 2010;Roseiro et al. 2013). The extracts were centrifuged at 8000 rpm for 15 min at 4 °C and the clarified supernatant was stored at À20 °C for further use. ...
... The extraction yield of sugars was above 92% for both solid/liq- uid ratios and reaching almost 100% sugar recovery at 1:10, demon- strating the feasibility and sustainability of this extraction process. Similar results are also reported in the literature ( Avallone et al., 1997;Manso et al., 2010). The concentration of extracted phenolic compounds was below 0.4 mg/mL for both extracts, ranging between 1 and 1.5 mg of GAE/ g carob powder (Table 1). ...
... It was observed that the yield of carbohydrates increased with time, as previously reported by Roseiro et al. (1991a), where the sugar concentration reached a steady state value (200 g/L) after 6 h of aqueous extraction at 20 • C (LSR = 2). While some literature, e.g., Manso et al. (2010), has claimed no significant difference in the extraction efficiency of carbohydrates with time, our results revealed a clear relationship, albeit mainly at lower temperatures. This finding is probably due to the high portion of carbohydrates (62% of their content in kibbles) which can be already recovered at shorter time i.e., 20 min (at the same extraction temperature of 47.5 • C). ...
... However, at 30 • C a high portion of carbohydrates (76%) can already be released from the carob kibbles and only a slight increase in the yield of carbohydrates was observed above this temperature (maximum 13%). This observation was in agreement with Manso et al. (2010), who claimed that temperature increase (25-75 • C) does not greatly improve the yield of sugar extraction. The effect of extraction time and temperature on the sugar recovery has been studied by several authors with different results. ...
... A longer extraction time seems to allow a higher carbohydrate extraction, but this is also not statistically significant. A LSR of 10 was proposed by Manso et al. (2010) for isolation of sugar (at 25 • C for 1 h) from milled carob, releasing about 94% of the sugar (corresponding to 47 g/L). Manso et al. (2010) found that at LSR of 20 no beneficial yield effect was observed. ...
Carob kibbles are a low-cost and renewable source of economically relevant phenolic compounds (high value catechin and its derivatives and gallic acid) and abundant in small sugars. This work aims at producing two distinct natural extracts from carob kibbles, one extract enriched in catechin and its derivatives for the nutraceuticals market and an extract enriched in sugars for the food industry. This valorisation strategy involves an integrated process based on membrane technology that fulfils the zero discharge principle and may be applied to other agro-industrial by-products. Different aqueous extraction schemes were considered (a one-step process and a two-steps approach). The aqueous extracts obtained were fractionated by diananofiltration and the fractions obtained were evaluated in terms of their content in target products. An integrated scheme for production of fractionated extracts is proposed based on the experimental work developed assuring, simultaneously, a minimal use of resources and emission of waste.
... It was observed that the yield of carbohydrates increased with time, as previously reported by Roseiro et al. (1991a), where the sugar concentration reached a steady state value (200 g/L) after 6 h of aqueous extraction at 20 • C (LSR = 2). While some literature, e.g., Manso et al. (2010), has claimed no significant difference in the extraction efficiency of carbohydrates with time, our results revealed a clear relationship, albeit mainly at lower temperatures. This finding is probably due to the high portion of carbohydrates (62% of their content in kibbles) which can be already recovered at shorter time i.e., 20 min (at the same extraction temperature of 47.5 • C). ...
... However, at 30 • C a high portion of carbohydrates (76%) can already be released from the carob kibbles and only a slight increase in the yield of carbohydrates was observed above this temperature (maximum 13%). This observation was in agreement with Manso et al. (2010), who claimed that temperature increase (25-75 • C) does not greatly improve the yield of sugar extraction. The effect of extraction time and temperature on the sugar recovery has been studied by several authors with different results. ...
... A longer extraction time seems to allow a higher carbohydrate extraction, but this is also not statistically significant. A LSR of 10 was proposed by Manso et al. (2010) for isolation of sugar (at 25 • C for 1 h) from milled carob, releasing about 94% of the sugar (corresponding to 47 g/L). Manso et al. (2010) found that at LSR of 20 no beneficial yield effect was observed. ...
... The carob tree (Ceratonia siliqua L.) is a Mediterranean perennial tree which produces pods containing seeds (10% w/w) and a highly rich sugar pulp (90% w/w), mainly containing sucrose, glucose and fructose, which may constitute as much as 50% of the carob pod mass ( Avallone et al., 1997;Manso et al., 2010). According to recent data, carob pod production worldwide accounts for almost 400,000 tons yearly of which 50,000 tons/year are produced in the Algarve, Portugal, turning the region into the third largest producer in the world ( Santos et al., 2005). ...
... Carob pulp was purchased from a local store as roasted carob flour. In order to maximize sugar extraction from carob pulp while minimizing the quantity of removed phenolic compounds, carob powder was suspended in distilled water at solid/liquid ratio 1:10 (w/v) and incubated at 25 °C in a rotary shaker at 200 rpm ( Manso et al., 2010;Roseiro et al., 2013b). Moreover, different times of extraction were tested: 0.5, 1, 3, 5, 7 and 9 h. ...
... Sugar composition and total phenolics content of aqueous carob pulp extracts obtained for different extraction times and solid/ liquid ratios are presented in Tables 1 and 2, respectively. The obtained water extracts are characterized by a high content of sol- uble sugars, including sucrose (more than 50% of total sugars), glu- cose and fructose (Table 1), similarly to what has been reported for de-seeded carob pods ( Avallone et al., 1997;Manso et al., 2010). Theoretically, sugar content of carob pulp can reach up to 50% of its mass content. ...
... Its price has fluctuated and is about 200 €/ton. The carob seeds represent 10% of the weight of the fruit and the pulp represents the other 90% [10]. Several authors have reported that carob pulp composition has a high content of sugars, mainly sucrose (more than 30%), fructose, and glucose with values of 20-50% [15], 45% [2], 48-56% [22], and 28-82% [4]. ...
... This gave economical relevance to carob pulp as an inexpensive and available feedstock for various biological products, e.g., dextran and fructose [18], citric acid [17], and ethanol [16]. The by-products from the carob processing industry are small carob kibbles, which contain a high content of sugar (mainly sucrose, glucose, and fructose) which are easily extractable by water, producing sugar-rich syrups [10]. ...
... Up to four leaching tests were conducted, with half initial ratio, to take full advantage of all soluble sugars in the carob pulp. These mixtures were homogenized at 150 rpm, 25°C for 1 h as suggested by Manso et al. [10,11]. After this period, to clarify the carob pulp extract, the mixtures were centrifuged at 7,500g, at 4°C for 15 min (Beckman J2-MC Centrifuge with a JA14 rotor), filtered through a 0.22-lm membrane filter, and stored at -20°C. ...
The waste materials from the carob processing industry are a potential resource for second-generation bioethanol production. These by-products are small carob kibbles with a high content of soluble sugars (45-50%). Batch and fed-batch Saccharomyces cerevisiae fermentations of high density sugar from carob pods were analyzed in terms of the kinetics of sugars consumption and ethanol inhibition. In all the batch runs, 90-95% of the total sugar was consumed and transformed into ethanol with a yield close to the theoretical maximum (0.47-0.50 g/g), and a final ethanol concentration of 100-110 g/l. In fed-batch runs, fresh carob extract was added when glucose had been consumed. This addition and the subsequent decrease of ethanol concentrations by dilution increased the final ethanol production up to 130 g/l. It seems that invertase activity and yeast tolerance to ethanol are the main factors to be controlled in carob fermentations. The efficiency of highly concentrated carob fermentation makes it a very promising process for use in a second-generation ethanol biorefinery.
... Carob tree (Ceratonia siliqua L. Leguminosae family) is widely cultivated in the Mediterranean regions, and in areas of North America (Blendford, 1979;Manso et al., 2010). The tree is considered an important flora for economic and environmental reasons (Batlle and Tous, 1997). ...
... Carob pod is used in various processes of food technology, medicine, and other industrial processes. At the industrial level, the pod was employed in the production of ethanol by Saccharomyces cerevisiae (Turhan et al., 2010;Roukas, 1995;Roukas, 1994a, b, Roukas, 1993, by Zymomonaras mobilis (Vaheed et al., 2011), the production of citric acid by Aspergillus niger (Roukas, 1998), the production of mannitol by lactic acid bacteria (Carvalheiro et al., 2011), and the production of biocontrol agent Pantoea agglomerans PBC-1 (Manso, 2010). The economical and industrial aspects of carob products were reviewed by (Davies et al., 1971;Ayaz et al., 2009). ...
Carob (Ceratonia siliqua L.) aqueous extracts were prepared from carob pods and kibble (pods minus seeds) particles of 0.5 to 1.0 cm diameter, at 45 °C for 2hr. Saccharomyces cerevisiae cells were grown on extracts by fed-batch method at 32 ºC, an optimal pH 5.5, and shaking at 300 rpm for 10 h. The cell yield and yield coefficient were 12.6 % and 0.27 g /g sugar utilized, respectively. Aeration effect and continuous feeding on the yield of Saccharomyces cerevisiae were studied on extracts prepared from carob pod powder or from chopped kibble. The biomass yield coefficient was about 0.27 g-yeast/g sugar utilized for both the pod and the kibble extracts. The cells maintained the availability of reducing sugars on the expense of non-reducing sugar present in carob extract; therefore, reducing sugars were maintained at their initial level. However, aeration and continuous feeding increased the yield to 113 %. Instantaneous growth rate constant after 10 h-period was 0.18 h -1 which decreased with time. Supplementation of Ca, Mg, N, and P salts to extract in a continuous fed-batch culture did not significantly increase the cell mass above the yield in the control. These nutrients were important in fixed batch culture. This indicates that, in cell division, the carbon source in the extract is not limiting factor, while the above additives become the limiting factor. Comparing the yield of the yeast grown on carob kibble extract with other substrates, previously and currently employed in the industry, reveals that the carob kibble extract is more economical substrate for industrial production of baker's yeast.
... etc. and the coastal regions of North Africa Egypt, Tunisia, Morocco and of course, Libya. In more recent years, it has even spread to parts of North America (Manso et al., 2010). ...
According to its location, geography, habitats, and its vegetation cover, El-Gabal El-Akhdar was described as one of the important ecological regions in Libya. Ceratonia silique L. is one of the plant species in the area and forms with other plants in the maquis plant community. Because of the ecological situation of the vegetation cover due to anthropogenic and physical factors, this plant was suggested to be in any rehabilitation programs in the future. Thus, the study of its ecological and physiological characteristics is very important. In this study fo,ur different locations in El-Gabal El-Akhdar were evaluated for carob plant population differences. Generally, no significant morphological differences were found among these populations except in highly significant leaf size. the second part of the study evaluated the germination of seeds using four pretreatments, compared to control all pretreatments significantly enhanced the germination of carob seeds, a relatively higher germination percentage was noticed in the seeds soaked in boiling water (96%). الخروب لنبات فسيولوجية بيئية اسة در (Ceratonia silique L.) األخضر الجبل بمنطقة بورزيزة فاطمة و الشطشاط سالم قسم النبات علم ، كلي ة العلوم ، بنغازي جامعة ، بنغازي ، ليبيا المستخلص: المفتاحية: الكلمات وصف األخضر الجبل علي بناء افيته وجغر موقعه ائله ومو وغطائ ه النباتي بأنه البيئية المناطق من يعتبر ليبيا. في المهمة الخروب نبات Ceratonia silique L. المنطقة في النباتية اع األنو أحد نباتات مجتمع أخرى نباتات مع ويشكل المكاي Maquis. و ا بسبب النباتي للغطاء البيئي لوضع عن الناجم السيء يائية الفيز و ية البشر امل العو ، فقد تأهيل إعادة امج بر أي في النبات هذا اح اقتر تم النباتي للغطاء المستقب في وبالتالي ل. خصائصه اسة در فإن في للغاية. مهمة الفسيولوجية و البيئية ا في مختلفة اقع مو بعة أر تقييم تم اسة الدر هذه األخضر لجبل ا اسة لدر الختالفات المورفولوجية لعشائر عام بشكل الخروب. نبات التجمعات هذه بين معنوية شكلية اختالفات على العثور يتم لم ، كانت التي الورقة حجم باستثناء عالية. إحصائية داللة ذات في اسة الدر من الثاني الجزء ت تم تقييم بع أر باستخدام البذور إنبات مسبقة معالجات ، و بال ً نة مقار شاهد ف ان المسبقة المعالجات جميع و ساهمت الخروب بذور إنبات كبير بشكل عززت متفاوتة بدرجات أعلى إنبات نسبة ولوحظت ، (المغلي الماء في المنقوعة البذور في ا ً نسبي 96 .)٪ ال األخض جبل ر ، الخروب نبات ، امج بر إعادة ال تأهيل، النباتي الغطاء ، ليبيا ، Ceratonia silique L.
... Major polyphenols found in carob kibbles have been tentatively identified, including gallic acid, myricetin 3-O-rhamnoside, quercetin p-hydroxy benzoyl 3-O-rhamnoside, and quercetin 3-O-rhamnoside [45]. Every year, 50,000 tons of carob fruit are grown in Portugal's Algarve region, which makes it difficult to dispose of the waste generated by this sector [46]. This waste requires the use of environmentally friendly and effective disposal methods. ...
The release of boron into the environment as a result of anthropogenic activity modifies sustainable natural conditions, thus affecting ecosystems. To meet water quality regulations, commercial and natural boron adsorbents are available to reduce its concentrations in industrial effluents, with the former being not only more expensive but also less sustainable. In the publication, the biosorption parameters of carob kibbles (Ceratonia siliqua L.) were optimized in order to remove boron from aqueous solutions using batch experiments. The biosorbent used in the present research was agro-waste biomass provided by the local locust-beam gum industry. Boron removal by carob kibbles was favored at high initial pH values, and this capacity was found to be a function of boron initial concentration, biosorbent content in the solution, and particle size. The change in temperature did not affect the potential of biomass to remove boron. The highest boron removal efficiency (55.1%) was achieved under the following optimal conditions: 50 g/L biosorbent dose (Cs), with particle size range 0.025–0.106 mm, for the initial concentration (C0) of boron in the solution of 100 mg/L, at an initial pH of 11.5, for 5 h at 25 °C. This investigation suggests that carob kibble agro-waste can be valorized as a biosorbent to remove boron from wastewater, and the boron-loaded residue may eventually be explored as a new boron-fertilizer.
... Ceratonia siliqua L. belongs to the subfamily Caesalpinioideae of the family Fabaceae, subordinate to the order of Leguminales (1). It is an ornamental and fruit tree distributed widely in the Mediterranean region, especially the eastern region in Libya (2,3). Its environmental requirements are arid, semi-arid regions, well in temperate regions, usually on rocky hill surfaces that are resistant to heat and droughts. ...
Organic residues are nitrogen-rich compounds that have been exploited as organic fertilizer among farmers in a classic method. So this study was conducted to find out the role of animal waste for breaking seed dormancy of Ceratonia siliqua as alternative chemical treatments, by included soaking seeds in cow dung slurry and chicken manure slurry for periods (24, 48, 72 hours). The results showed the effectiveness of organic residues in breaking the dormancy of tested seeds. The soaking treatment in cow dung for 24 hours was superior in recording the highest percentage of germination (63.3, 81.6%) and the lowest average germination time was within 10-20 days. The results were also showed the length of soaking time in organic residues led to lower germination rates.
... Commercial products such as dried beer yeast, soy powder, sucrose, fructose, skimmed milk, malt extract, and apple concentrate, as well as by-products such as middling, meat-derived flour, whey, and molasses, could be successfully combined to considerably reduce the production costs [10]. Similarly, the low-cost production for P. agglomerans strain PBC-1 by either batch-feeding or discontinuous feeding of the bioreactor was also optimized using carob pulp as a carbon source [11,12]. The strain CPA-8 of Bacillus amyloliquefaciens, effective against brown rot in stone fruit, was produced using two low-cost media composed of either defatted soy flour [13] or the isolated soy protein PROSTAR 510 A with 90% of protein (Brenntag Química S.A.U., Barcelona, Catalonia, Spain) [14] combined with sugar cane molasses (high sugar content around 50% w/w sucrose, glucose, and fructose) as carbon source and trace minerals. ...
Biocontrol agents (BCAs) have been proposed and studied over recent decades as a suitable alternative to diminish or substitute synthetic fungicides used to control pre- and postharvest diseases. However, the development of BCAs has many constraints and obstacles that would have to be overcome before they could be successfully implemented in the market. For the BCA commercial development, the microorganism should be mass-produced on a large-scale, and, independently of the method used for the production, a particular plan regarding the formulation of BCAs by multidisciplinary approaches (liquid or solid) is required to optimize the yield, efficacy, and shelf life of the developed product. Unfortunately, not all BCAs can survive the conditions imposed during the formulation process. Improved stability can be achieved by either using special conditions during growing or by adding protective substances to the formulation medium. Finally, BCAs should be formulated in such a way as to guarantee long-term stability and ease of application of the product. Therefore, an accurate range of the packaging conditions should be considered to extend the shelf life of the formulated product, preferably up to two years. Herein, we discussed the main aspects regarding the production, formulation, packaging, and shelf life of BCAs.
... Besides, it consists of minor amounts of minerals, pectin, phenolic compounds, and amino acids [11]. Due to its high sugar concentration, carob is employed for the generation of high value-added products such as citric acid [12], lactic acid [13], mannitol [14], biocontrol agent (fungicide: Pantoea agglomerans PBC-1) [15], pullulan [16], D-pinitol [17], β-mannanase [18], and inulinase [19,20]. Additionally, ethanol as a biofuel can be generated from carob pod via different fermentation strategies (suspended cells [21], immobilization [22], biofilm reactor [23], solid-state fermentation [24]). ...
In this study, various mathematical functions were utilized to fit the observed values and the kinetic parameters of fermentation in immobilized-cells stirred tank reactor (ICSTR) with carob extract medium (CEM). The best model was selected based on the residual sum of squares (RSS), root-mean-square-error (RMSE), mean-absolute-error (MAE), determination coefficient (R2), slope (m), bias factor (BF), accuracy factor (AF), the objective function (Φ-factor), and f-testing. Therefore, the Stannard (ST) model was good agreement with the actual biomass production (X), ethanol production (P), and sugar consumption (S) data (RSS=0.22, 6.23, and 45.70 g/L, RMSE=0.17, 0.88, and 2.39 g/L, MAE=0.14, 0.64, and 1.72 g/L, R2=0.9948, 0.9977, and 0.9972, m=1.03, 1.02, and 1.02, BF=1.35, 1.08, and 0.97, AF=1.41, 1.14, and 1.04, and Φ-factor=0.008, 0.004, and 0.005 (∑Φ-factor=0.017) for X, P, and S, respectively). In the prediction of kinetic parameters belong to the experimental fermentation, the ST model also gave better, satisfactory, and well-directed results than the other mathematical models. Besides, the ST model was also accomplishedly validated using two independent sets of the experimental data yielded from the different carbon sources in various concentrations. Consequently, the models proposed for X, P, and S can serve as universal functions to predict the real values and the kinetic parameters of the ethanol fermentation. Besides, these models can be applied to improve the ethanol fermentation in the ICSTR with CEM.
Keywords: Saccharomyces cerevisiae, ethanol fermentation, immobilized-cell stirred tank bioreactor, carob extract, modeling
... According to 2018 data from the Food and Agricultural Organization of the United Nations, its production quantity and yield were used to produce several products such as locust bean gum, sweets, biscuits, and traditional carob concentration Yatmaz and Turhan, 2018). On the other hand, the carob is rich-sugar and therefore can be used for the production of many value-added products such as citric acid (Lingappa et al., 2007), lactic acid (Germec et al., 2018a;Turhan et al., 2010a), mannitol (Carvalheiro et al., 2011), biocontrol agent (fungicide: Pantoea agglomerans PBC-1) (Manso et al., 2010), ethanol (Ercan et al., 2013;Germec, 2014;Germec et al., 2019a;Germec et al., 2018bGermec et al., 2016;Germec et al., 2015Germec et al., , 2019cTurhan et al., 2010b), D-pinitol (Oziyci et al., 2015;Tetik et al., 2011;Tetik and Yüksel, 2014), β-mannanase Germec et al., 2017;Karahalil et al., 2019a;Karahalil et al., 2019b;Yatmaz et al., 2016a;Yatmaz et al., 2016b), and inulinase Ilgın et al., 2019). Accordingly, as a continuation of our previous study (Ilgın et al., 2019), carob has been used as a carbon source in the production of Aspergillus niger A42 inulinase in the submerged fermentation in this study, due to its high level of sugar content (62-67% total soluble solids, 34-42% sucrose, 7-10% glucose, and 10-12% fructose) (Yatmaz and Turhan, 2018). ...
This study aimed to optimize inulinase production conditions from carob extract by using the Box-Behnken Design of Response Surface Methodology, to purify partially with ultrafiltration, and to model kinetically the
inulinase fermentation. Based on the results, the optimal conditions were 250 rpm agitation speed, 2.3% inoculum size (v/v), and 135 mL medium volume, which yielded 1560.17 U/mL inulinase activity, 1198.36 U/mL invertase-type activity, 1.30 I/S ratio, 163.06 U/mL/d maximum inulinase fabrication rate, and 193.37 U/mL/d maximum invertase-type fabrication rate. With the ultrafiltration process, the inulinase and invertase-type activities were increased to 6278.69 and 7622.39 U/mL with 1.19 and 1.50 purification coefficients, respectively. Regarding modeling with the Luedeking-Piret model, enzyme and protein productions were not related to the substrate depletion due to negative a values. Consequently, carob extract can be evaluated for the fabrication conditions of A. niger inulinase and the purified enzyme can be used for the fabrication of fructooligosaccharides.
... 2,[18][19][20][21][22][23][24][25][26][27][28] In addition, carob has been used successfully in the production of lactic acid, 29,30 mannitol, 31 docosahexaenoic acid, 32 citric acid, 33 succinic acid, 34 inulinase, 35,36 β-mannanase, 37-42 polyhydroxybutyrate, 43 carotenoids, 44 and bio-control agent. 45 Therefore, it can be used for the fabrication of high value-added products by fermentation process in the industrial scale. ...
In this study, various functions were evaluated and utilized to forecast observed values and kinetic parameters of the batch ethanol fabrication from carob extract in the suspended‐cell stirred tank reactor (SCSTR). The best model was detected with the model comparison parameters (root‐mean‐square‐error [RMSE], mean‐absolute‐error [MAE], and R 2 ). The results indicated that the model Stannard (ST) successfully predicted biomass production data (RMSE = 0.26 g L⁻¹, MAE = 0.18 g L⁻¹, and R 2 = 0.9910), ethanol fabrication data (RMSE = 2.44 g L⁻¹, MAE = 1.88 g L⁻¹, and R 2 = 0.9809), and sugar depletion data (RMSE = 2.82 g L⁻¹, MAE = 2.17 g L⁻¹ and R 2 = 0.9938). Nevertheless, the lowest value of the objective function (Φ ‐factor) was also yielded as 0.041 using the model ST. Additionally, in the estimation of the kinetic data, the model ST also gave well‐directed results. Besides, when an independent set of the observed values was utilized to confirm the mathematical functions, the satisfactory consequences were achieved in terms of both the experimental and kinetic values. Consequently, the model ST can work as a universal function in predicting observed values and kinetics of batch ethanol generation from carob extract in an SCSTR.
... The use of byproducts from the carob processing industry as an alternative carbon source is already common for several bioprocesses (Carvalheiro, Moniz, Duarte, Esteves, & Gírio, 2011;Mendes et al., 2007;Sánchez-Segado et al., 2012). Carob industrial wastes are small carob kibbles with a high content of soluble sugars, mainly sucrose, glucose, and fructose, which are easily extractable by water producing sugar-rich liquors (Manso, Nunes, Raposo, & Lima-Costa, 2010). However, these liquors are also rich in sulfates and easy access to sulfur sources, and so they cannot be directly used for BDS. ...
The biodesulfurization (BDS) process consists of the use of microorganisms for the removal of sulfur from fossil fuels. Through BDS it is possible to treat most of the organosulfur compounds recalcitrant to the conventional hydrodesulfurization (HDS), the petroleum industry's solution, at mild operating conditions, without the need for molecular hydrogen or metal catalysts. This technique results in lower emissions, smaller residue production, and less energy consumption, which makes BDS an eco-friendly process that can complement HDS making it more efficient. BDS has been extensively studied and much is already known about the process. Clearly, BDS presents advantages as a complementary technique to HDS; however, its commercial use has been delayed by several limitations both upstream and downstream the process. This study will comprehensively review and discuss key issues, like reduction of the BDS costs, advances, and/or challenges for a competitive BDS towards its potential industrial application aiming ultra-low sulfur fuels.
... A significant portion of soluble dry matter is composed of sucrose (34-42%), fructose (10-12%), and glucose (7-10%). 22 Due to its high sugar content, the high value-added products such as ethanol, 1,23-26 lactic acid, 27 mannitol, 28 citric acid, 29 mannanase, 2,30,31 and bio-control agent (fungicides: Pantoea agglomerans PBC −1) 32 have been generated from carob by biotechnological processes. Therefore, in this study, because of the current potential of carob, it can be evaluated in the production of A. niger A42 inulinase in shake flask fermentation. ...
The main objectives of the study were to produce inulinase from carob extract by Aspergillus niger A42 (ATCC 204447) and to model the inulinase fermentation in the optimum carob extract‐based medium. In the study, carob extract was used as a novel and renewable carbon source in the production of A. niger inulinase. For medium optimization, eight different variables including initial sugar concentration (°Bx), (NH4)2HPO4, MgSO4.7H2O, KH2PO4, NH4NO3, yeast extract, peptone, and ZnSO4.7H2O were employed. After fermentations, optimum medium composition contained 1% yeast extract in 5°Bx carob extract. As a result of the fermentation, the maximum inulinase activity, maximum invertase‐type activity, I/S ratio, maximum inulinase and invertase‐type activity rates, maximum sugar consumption rate, and sugar utilization yield were 1507.03 U/mL, 1552.86 U/mL, 0.97, 175.82 and 323.76 U/mL/day, 13.26 g/L/day, and 98.52%, respectively. Regarding mathematical modeling, the actual inulinase production and sugar consumption data were successfully predicted by Baranyi and Cone models based on the model evaluation and validation results and the predicted kinetic values, respectively. Consequently, this was the first report in which carob extract was used in the production of inulinase as a carbon source. Additionally, the best‐selected models can serve as universal equations in modeling the inulinase production and sugar consumption in shake flask fermentation with carob extract medium. This article is protected by copyright. All rights reserved.
... • Carob Pulp: The use of byproducts from the carob processing industry as an alternative carbon source is already common for several bioprocesses (Carvalheiro, Moniz, Duarte, Esteves, & Gírio, 2011;Mendes et al., 2007;Sánchez-Segado et al., 2012). Carob industrial wastes are small carob kibbles with a high content of soluble sugars, mainly sucrose, glucose and fructose, which are easily extractable by water producing sugar-rich liquors (Manso, Nunes, Raposo, & Lima-Costa, 2010). However, these liquors are also rich in sulfates and easy access sulfur sources, and so they cannot be directly used for BDS. ...
Biodesulfurization (BDS) process consists on the use of microorganisms for the removal of sulfur from fossil fuels. Through BDS it is possible to treat most of the organosulfur compounds recalcitrant to the conventional hydrodesulfurization (HDS), the petroleum industry's solution, at mild operating conditions, without the need for molecular hydrogen or metal catalysts. This technique results in lower emissions, smaller residue production and less energy consumption, which makes BDS an eco-friendly process that can complement HDS making it more efficient. BDS has been extensively studied and much is already known about the process. Clearly, BDS presents advantages as a complementary technique to HDS; however its commercial use has been delayed by several limitations both upstream and downstream the process. This study will comprehensively review and discuss key issues, like reduction of the BDS costs, advances and/or challenges for a competitive BDS towards its potential industrial application aiming ultra low sulfur fuels.
... [15] The carob tree (Ceratonia siliqua L.) is a Mediterranean perennial tree that produces pods containing seeds (10% w/w) and a highly rich sugar pulp (90% w/w), which may constitute as much as 50% of the carob pod mass. [16] Although the worldwide carob pod production accounts for almost 400,000 tons/year, a large portion of this is discarded since it is considered a by-product of the carob locust bean gum industry. Thus, carob pod represents a promising feedstock for the bio-industry. ...
Experiments were performed for comparing and selecting the most appropriate precipitation strategy for succinic acid (SA) recovery from carob pod extract fermentation broths. The performances of three downstream options – employing calcium hydroxide, magnesium hydroxide or ammonia – were investigated and compared from operational, techno-economical and sustainability viewpoints. The highest SA recovery (84.3%) was obtained with ammonia, whereas the calcium-based treatment proved inadequate. Sustainability indicators favoured magnesium-based treatment, closely followed by the ammonia-based one. A preliminary economic analysis favours magnesium-based treatment, which appears to be the most feasible option. However, materials recycling and possible by-products commercialization could well position also ammonia-based treatment.
... Due to the growing awareness of the society with respect to environmental protection and increased concern about health, alternatives to chemical methods of plant protection are sought. Hope is seen in biological methods based on natural agents that inhibit the development of undesirable microflora (Gerhardson, 2002;Manso et al., 2010). The search for isolates with effective protective properties, mainly against phytopathogens, is based on testing their antagonistic action, identification of promising strains, and their subsequent use in the production of biologicals. ...
Growth kinetics of four Trichoderma strains was tested on lignocellulosic by-products in solid state fermentation (SSF). The strains were also analyzed for their survival rate and growth after lyophilization on these carriers. All applied monocomponent and bicomponent media were substrates for the production and preservation of Trichoderma biomass. However, the maximum number of colony forming units (CFU/g dm) was acquired on bicomponent media based on dried grass and beet pulp or grass with corn cobs, when compared to monocomponent media. Although the process of lyophilization reduced the survival rate by 50–60%, the actual number of viable cells in obtained biopreparations remained relatively high (0.58 × 108 – 1.68 × 108 CFU/g dm). The studied strains in the preserved biopreparations were characterized by a high growth rate, as evaluated in microcultures using the Bioscreen C system.
... Nowadays, the main application of the pulp is as an animal feed (Manso et al., 2010). In human the carob pulp has been used mainly as a cocoa substitute (Kumazawa et al., 2002;Ben-goechea et al., 2008), in pharmaceutical products (Calixto and Canellas, 1982) and ethanol production (Turhan et al., 2010). ...
The aim of this work is to provide a process for obtaining natural carob syrup of
Morocco carob pods and their total and reducing sugar. Samples were collected from different
regions in the agro-forestry system of Morocco. The total sugar and reducing sugar in pods
obtained from different regions were 31.5–50.1 and 10.2–14.6 g/100 g ‘‘%w/w’’, respectively. The
yield of syrup from the different regions varies between 28.76 and 37.22 g/100 g ‘‘%w/w’’. Popula-
tions from Essaouira and Beni-mellal have higher levels of sugar and yield of syrup. The values
obtained vary according to the origin of the samples.
... Nowadays, the main application of the pulp is as an animal feed [11]. In human the carob pulp has been used mainly as cocoa substitute [12,13], in pharmaceutical products [14] and in ethanol production [15]. ...
The aim of this work is to provide a process
for obtaining natural carob syrup of Morocco carob pods
and their total and reducing sugar. Samples were collected
from different regions in the agro-forestry system of
Morocco. The total sugar and reducing sugar in pods
obtained from different regions were 31.5–50.1 and 10.2–
14.6 g/100 g (%w/w), respectively. Experimental design was
used to investigate the effect of three parameters (extraction
temperature, extraction time and ratio of water to pulp) on
syrups yields. The ranges of the factors investigated were
20–45°C for extraction temperature (X1), 1–3h for
extraction time (X2) and 1–3 for extraction ratio of water to
pulp (X3). The extracting parameters for syrups yields
were optimized by using three-factor-three-level Box
Behnken design (BBD) and response surface methodology
based on the single-factor experiments. As results, the
optimum conditions were extracting temperature 43.45°C,
extracting time 2.40 h and the ratio of extraction solvent
(water) to pulp (v/w) 2.27. Under these conditions, the
experimental values were in close agreement with values
predicted by the model and for wish. The yield of syrup
from the different regions varies between 28.76 and 37.22
g/100 g (%w/w). Populations from Essaouira and Beni-
Mellal have higher levels of sugar and yield of syrup. The
values obtained vary according to the origin of the samples.
Keywords— Carob pods; provenance of carob; pulp
yield; total sugars; reducing sugars; optimization
experiment; Box Behnken design; syrup yield.
... Absence of large-scale production of bio-pesticides is one of the major constraints in the wider application of many biopesticides. Carob pulp aqueous extracts were used as carbon source in the production of the biocontrol agent Pantoea agglomerans PBC-1, used as a bio-pesticide [340]. A 78% reduction of the pathogen incidence was achieved with PBC-1 at 1 Â 10 8 cfu/ml of fermentation media. ...
The concentrations of phenolics and other phytochemicals present in the peels, pulp/pomace and
seeds of many fruits and vegetables namely citrus, apples, peaches, pears, banana, pomegranate,
berries, mangoes, onions, potatoes, tomatoes and sugar beet are generally substantially higher than in their respective edible tissues, suggesting these wastes and residues to be the potential sources for isolating bio-active compounds. The antioxidants (polyphenolic and other phytochemicals) and other bio-active compounds from these sources exhibit anti-cancer, anti-microbial (pathogens), anti-oxidative and immune-modulatory effects. In addition they reduce incidence of cardiovascular diseases and capillary fragility, inhibit platelet aggregation and prevent thrombosis, oxidative stress, osteoporosis and diabetes in vertebrates. Specifically, the phenolics and flavonoids present in apple, date pit, rambutan (Nephelium lappaceum) peel, tomato peel extracts strongly inhibit tumour-cell proliferation. Penta-O-galloyl-glucoside (PGG) present in mango seed kernel extract and mango peel is used in pharmaceutical industries as it possesses anti-tumor, antioxidant, anticardiovascular and hepato-protective effects. The terpenoid and flavonoids in banana foliage exhibit anthelmintic properties. Pomace of apple, pear, orange, peach, blackcurrant, cherry, artichoke, asparagus, onion, raspberry, tomato and carrot, durian seeds (gelling and thickening agents), mango peels, date pits, cauliflower trimmings, empty pea pods and okara are used as dietary fibre supplements and as a functional ingredient in processed food products due to the presence of pectins and carotenoids and bound antioxidants. Some of the fruit and vegetable wastes are excellent source of biopigments; examples being betalains in beet root pulp and carotenoid in carrot pulp. Tomato seeds, banana peel, rambutan and mango seed kernel, passion fruit seed, black currant, date pits are good sources of edible oil rich in polyunsaturated fatty acids. Many fruit and vegetable wastes are used as a substrate for the production of organic acids (citric, lactic and ferulic acids), single cell protein, essential oils, exogenous enzymes, bio-ethanol/methanol, bio-pesticides, bio-sorbants, bio-degradable plastic, bio-fertilizers, bio-preservatives and edible mushrooms. Some have potential to decrease the emission of enteric methane.
... Absence of large-scale production of bio-pesticides is one of the major constraints in the wider application of many biopesticides. Carob pulp aqueous extracts were used as carbon source in the production of the biocontrol agent Pantoea agglomerans PBC-1, used as a bio-pesticide [340]. A 78% reduction of the pathogen incidence was achieved with PBC-1 at 1 Â 10 8 cfu/ml of fermentation media. ...
The concentrations of phenolics and other phytochemicals present in the peels, pulp/pomace and seeds of many fruits and vegetables namely citrus, apples, peaches, pears, banana, pomegranate, berries, mangoes, onions, potatoes, tomatoes and sugar beet are generally substantially higher than in their respective edible tissues, suggesting these wastes and residues to be the potential sources for isolating bio-active compounds. The antioxidants (polyphenolic and other phytochemicals) and other bio-active compounds from these sources exhibit anti-cancer, anti-microbial (pathogens), anti-oxidative and immune-modulatory effects. In addition they reduce incidence of cardiovascular diseases and capillary fragility, inhibit platelet aggregation and prevent thrombosis, oxidative stress, osteoporosis and diabetes in vertebrates. Specifically, the phenolics and flavonoids present in apple, date pit, rambutan (Nephelium lappaceum) peel, tomato peel extracts strongly inhibit tumour-cell proliferation. Penta-O-galloyl-glucoside (PGG) present in mango seed kernel extract and mango peel is used in pharmaceutical industries as it possesses anti-tumor, antioxidant, anticardiovascular and hepato-protective effects. The terpenoid and flavonoids in banana foliage exhibit anthelmintic properties. Pomace of apple, pear, orange, peach, blackcurrant, cherry, artichoke, asparagus, onion, raspberry, tomato and carrot, durian seeds (gelling and thickening agents), mango peels, date pits, cauliflower trimmings, empty pea pods and okara are used as dietary fibre supplements and as a functional ingredient in processed food products due to the presence of pectins and carotenoids and bound antioxidants. Some of the fruit and vegetable wastes are excellent source of biopigments; examples being betalains in beet root pulp and carotenoid in carrot pulp. Tomato seeds, banana peel, rambutan and mango seed kernel, passion fruit seed, black currant, date pits are good sources of edible oil rich in polyunsaturated fatty acids. Many fruit and vegetable wastes are used as a substrate for the production of organic acids (citric, lactic and ferulic acids), single cell protein, essential oils, exogenous enzymes, bio-ethanol/methanol, bio-pesticides, bio-sorbants, bio-degradable plastic, bio-fertilizers, bio-preservatives and edible mushrooms. Some have potential to decrease the emission of enteric methane.
... Broccoli byproducts may be used as a source of bioactive ingredients to design novel beverages-using organic green tea as a food matrix-presenting improved physical quality, phytochemical composition and antioxidant capacity (Dominguez-Perles et al., 2011). Carob pulp aqueous extracts were used as carbon source in the production of the biocontrol agent Pantoea agglomerans PBC-1, usable as bio-pesticide (Manso et al., 2010). Tests proved that the aqueous extracts exhibit a high potential of this by-product as a carbon source to produce high amounts of biomass of the biocontrol agent at low cost. ...
The production of food waste covers all the food life cycle: from agriculture, up to industrial manufacturing and processing, retail and household consumption. In developed countries, 42% of food waste is produced by households, while 39% losses occur in the food manufacturing industry, 14% in food service sector and remaining 5% in retail and distribution. Increasingly, industrial ecology concepts such as cradle to cradle and circular economy are considered leading principle for eco-innovation, aiming at “zero waste economy” in which waste are used as raw material for new products and applications. The large amount of waste produced by the food industry, in addition to being a great loss of valuable materials, also raises serious management problems, both from the economic and environmental point of view. Many of these residues, however, have the potential to be reused into other production systems, trough e.g. biorefineries. The present work focuses on the use of food waste coming from food manufacturing (FWm). Through extensive literature review, the authors present feasibility and constraints of applying industrial symbiosis in recovering waste from food processing, focusing on recycling (excluding energy recovery) of the solid and liquid waste from food processing industry. The main uses of functional ingredients derived from this transformation are presented and discussed, highlighting mainstream sectors of application, e.g. in the nutraceutical and pharmaceutical industry.
... One of these is the carob tree Ceratonia siliqua; a native tree of the East Mediterranean; which is flourishing in this area since antiquity, usually in mild and dry places with poor soils, and has great economic importance from both industrial as well as nutritional point of view [8,9,10,11,12,13,14,15,16,17,18]. Lot of work has been done on its physiological behaviour [19,20,21,22]. Its value was recognized by the ancient Greeks, who brought it from Middle East to Greece and Italy, and by the Arabs, who disseminated it along the North African coast and north into Spain and Portugal. ...
The carob tree (Ceratonia siliqua L.) is widely cultivated in Mediterranean countries including Greece and Turkey. Carob pod is the fruit of carob tree. The present study reports the changes of chemical characteristics of two types (fleshy and wild) Greek and one type (fleshy) of Turkish carob pods during one period harvesting. The content of protein, total polyphenols, fatty acids and sugars, which are substances of vital importance for the evaluation of their food and medicine quality were determined at three growth stages. Sucrose, glucose and fructose were the major sugars identified and quantified in the fruit. In the first growth stage the predominant fatty acid in Turkish carobs was oleic followed by linoleic, palmitic and linolenic fatty acids while in Greek carobs the major acid was linoleic (n-6). During maturation an increase in oleic acid and a sharply decrease in linoleic and linolenic (n-3) fatty acids were noticed in both Greek and Turkish samples. Turkish carobs appeared higher level of total sugars, fructose and sucrose content than the Greek ones in the first growth stage. A higher ratio of total unsaturated / saturated fatty acids was found in Greek than in Turkish mature fleshy carob pods. Our results could aid in the assessment of adequate compositional information for further studies.
... It is also exploited for its synergy property with carrageenan, agar and xanthan to form stronger and more elastic gels (Hoichman et al., 2007). Nowadays, the main application of the pulp is as an animal feed (Manso et al., 2010). In human the carob pulp has been used mainly as a cocoa substitute (Kumazawa et al., 2002; Ben goechea et al., 2008), in pharmaceutical products (Calixto and Canellas, 1982) and ethanol production (Turhan et al., 2010). ...
The aim of this work is to provide a process for obtaining natural carob syrup of Morocco carob pods and their total and reducing sugar. Samples were collected from different regions in the agro-forestry system of Morocco. The total sugar and reducing sugar in pods obtained from different regions were 31.5–50.1 and 10.2–14.6g/100g “%w/w”, respectively. The yield of syrup from the different regions varies between 28.76 and 37.22g/100g “%w/w”. Populations from Essaouira and Beni-mellal have higher levels of sugar and yield of syrup. The values obtained vary according to the origin of the samples.
Aim: The aim of this study was to investigate the effect of carob pulp flour addition on probiotic viability, milk fermentation (pH, acidity and syneresis) and antioxidant activity, during yogurt cold storage (4 °C, 28 days). Methods: Four types of yogurts were prepared: plain yogurt (Y); yogurt with carob pulp flour (YC); yogurt with probiotic (YP) and yogurt with carob pulp flour and probiotic (YPC). Results: Ceratonia siliqua L. pulp flour supplementation (4% w/v) increased probiotic survival (15.96 %), titratable acidity (27.65 %) and syneresis (30.13 %). Carob pulp flour improved antioxidant activity for both DPPH (62.8 %) and iron chelating test (35.81 %), where yogurt containing probiotic and carob exhibited the highest antioxidant activity. Carob pulp flour had a selective effect on probiotic growth implying its prebiotic potential. Probiotic bacteria were viable and available at high concentration (> 106 CFU/mL) at 28 day storage to sustain human health. Conclusion: Our results show that Algerian Carob can be considered as a very potential prebiotic, stimulating the growth of beneficial bacteria and exert strong antioxidant activity due to the presence of polyphenols.
In terms of sustainability and circular economy, agricultural by-products may be efficiently reused in insects’ rearing for high-quality protein sources in human diet and animal feeds. The present study aimed to explore whether the utilization of carob pods as feeding substrate may beneficially affect Tenebrio molitor’s growth, nutritional value, antioxidant status and cellular responses. Increasing levels of milled whole carob pods (0, 25, 50, 75, 100%) were used as alternative wheat bran (control) substrates for yellow mealworm rearing, while growth performance, proximate composition, total phenolic content, antioxidant enzyme activity and the expression of stress- and apoptotic-related proteins were evaluated in larvae. The results showed that carob pods’ content up to 75% did not significantly differentiate larvae weight, development time and total dry matter. Larvae total phenolic content and antioxidant activity exhibited a significant increase at 75% content. Although the antioxidant enzymes’ activity decreased at both 25 and 50% levels, higher carob content levels (75 and 100%) resulted in no significant changes compared to the control. Carob pods led to decreased apoptotic indicators and the low expression of most stress-related proteins compared to the control. The present findings demonstrate that carob pods and their antioxidant properties exert beneficial effects on T. molitor’s rearing and nutritional status, although 100% carob content may impact adversely the larvae due to the high amounts of carob tannins.
أجريت هذه الدراسة في كلية العلوم / جامعة عمر المختار، لتحسين إنبات بذور أشجار الخروب Ceratonia siliqua L. البرية والمستزرعة باستخدام عدة معاملات مختلفة شملت معاملة النقع في الماء الساخن لفترات زمنية (20، 40، 60) دقيقة، والخدش الميكانيكي، وخدش ميكانيكي مع النقع في الماء المقطر، والخدش الميكانيكي مع النقع في الجبريلين 500ppm، والنقع في الجبريلين تركيز 750، 1000، 1250ppm، وأخيرا النقع في حمض الكبريتيك تركيز50، 70، 90%، أشارت النتائج إلى تفوق معاملة الخدش مع النقع في الجبريلين 500ppm على جميع المعاملات بنسبة إنبات 98%، وبمتوسط زمن إنبات 2.88 يوماً، كما سجلت زيادة في طول الجذير، والوزنين الطازج والجاف للبادرة، بينما كانت معاملة النقع في الجبرلين أقل المعاملات كفاءة في تحسين إنبات البذور ومؤشراته، وأشارت النتائج إلى عدم وجود فروق معنوية بين بذور الخروب البرية والمستزرعة للصفات المدروسة، وخلصت الدراسة إلى أن معاملة بذور الخروب بالخدش مع النقع في الجبريلين500ppm هي الأكثر كفاءة في تحسين الإنبات.
One of the major moral challenges for modern society is the fact that nearly one in ten people in the world is exposed to severe levels of food insecurity, and an estimated 2 billion people worldwide cannot rely on safe, nutritious, and sufficient food, whereas industrialized countries are dealing with over-consumption of food, food-related diseases and increasing food waste production; this represents an environmental, economic, and ethical challenge for the modern society. This chapter deals with the classification of food waste sources and lists an impressive number of the high-value target compounds that can be obtained at different scale-up levels (from the lab-scale up to the biorefinery level), depending on food waste and technology availability.
Use of lignocellulosic materials and agricultural wastes/products in
biotechnological processes has recently increased due to these resources have high sugar content. Accordingly, production of high value added products such as enzyme, organic acid, biofuel is important from the point of economy. In this study, repeated-batch
fermentation was evaluated using a biofilm reactor for ethanol production from carob pod extract by Saccharomyces cerevisiae. Primarily, biofilm material was determined to provide for attachment on surface of yeast and then optimization of ethanol production
from carob pod extract was performed at optimum conditions of response surface method. Thus, the effect of different combinations of nitrogen sources on fermentation was evaluated at optimum conditions determined. Besides, ethanol fermentation was carried
out under optimum conditions in non-enrichment medium as control. Nevertheless, the ethanol fermentations were performed using non-sterile enrichment and non-enrichment medium and their effect on fermentation was investigated. Plastic Composite Support (PCS) material that causing biofilm formation providing on surface attachment of yeast in biofilm reactor was used. In order to determine the best biofilm material, four different PCS materials were used as following SH-SF-YE-SALTS, SH-SF-YE-BA-SALTS, SH-SF-SALTS and SH-SF-YE-RBC-SALTS. The highest ethanol production was obtained from biofilm material including SH-SF-YE-BA-SALTS. Then, selected PCS material was bonded on shaft in bioreactor and biofilm formation was performed to establish on PCS material. After optimization of ethanol production from carob pod extract was performed at conditions of response surface method. These conditions were selected as initial sugar concentration (4, 7 and 10ºBx), pH (5.0, 5.5 and 6.0) and agitation (100, 150 and 200 rpm). Optimum conditions were found to be 7.71ºBx, 5.18 pH and 120 rpm after fermentations. At the end of the determination optimum conditions, the effect of different combinations of nitrogen sources on fermentation in optimum conditions was researched. Consequently, the kinetic parameters such as yield, maximum consumption rate and maximum production rate of nitrogen sources were determined to be significantly important impact. Besides, ethanol fermentations in biofilm reactor were carried out in sterile non-enrichment (control), non-sterile enrichment and non-enrichment medium. Results showed that obtained yields and production rates were lower then optimum conditions scored. Overall, this study demonstrated that ethanol productions in a biofilm reactor from carob pod extract using Saccharomyces cerevisiae can be successfully implemented. Product yield and productivity were increased due to high cell concentration in biofilm reactor and biofilms attachment on PCS surface and fermentation time was determined as 12 hours.
Abstract: This study was conducted at the Faculty of Science / Omar Al-Mukhtar University to improved the tree seeds germination of Carob (Ceratonia siliqua L.) wild and cultivated by using a number of different treatments, inclued the treatment of soaking in hot water for periods (20, 40 and 60) minute, scarified mechanical, scarified mechanical with soaking in distilled water, and scarified mechanical soaking in gibberellin 500ppm, without scarifying and with soaking in gibberellin concentrations 750, 1000, and 1250 pmm, and with soaking in concentrations 50, 70, and 90% Of sulphruic acid. The treatment of scarifying with soaking in gibberellin 500ppm was moer efficiency than all treatments with germination percentage (98%), germination time (2.88 day), and the best averages of germination index, as root length, fresh weight, and dry weight of the seedling. While the lowest germination percentage and longest germination time was was recorded treatment of soaking in different concentrations of gibberellin. The results showed no significant differences between wild and planted Ceratonia siliqua L. seeds for studied traits. The study concluded that the treatment of Ceratonia siliqua L.seeds by scarifying with soaking in gibberellin 500ppm was the most efficient in improving germinatio
This chapter contains sections titled: Introduction Effect of Incubation Period Effect of Temperature and pH Effect of Dissolved Oxygen Concentration Effect of Agitation Speed Effect of Initial Biomass Concentration Effect of Biocatalyst Age Effect of Mass Transfer Effect of Surfactant Effect of Initial Sulfur Concentration Effect of Type of S‐Compounds Effect of Organic Solvent and Oil to Water Phase Ratio Effect of Medium Composition Effect of Growing and Resting Cells Inhibitory Effect of Byproducts Statistical Optimization
Le caroubier est considéré comme l'un des arbres fruitiers et forestiers qui présente le plus grand potentiel de valorisation puisque toutes les parties de cette plante sont utilisables dans plusieurs applications industriels. Le caroubier est cultivé dans plusieurs régions du Liban mais peu d'études sont disponibles sur les voies de valorisation et sur les propriétés fonctionnelles et structurales des graines et des gousses. Ainsi, dans le cadre d'une démarche qui vise à promouvoir et contribuer à une meilleure valorisation et gestion de cette ressource renouvelable, nous avons entrepris dans cette thèse des travaux consacrés à la caractérisation et à l'évaluation de la valeur nutritive et fonctionnelle des gousses de caroube issues de plusieurs régions libanaise. Ces travaux ont porté notamment sur la caractérisation morphologique et physico-chimique des gousses et sur la purification des gommes extraits des graines. Ces gommes ont fait l'objet d'une étude approfondie portant sur leur comportement rhéologique et la relation entre ce comportement, la variété et le lieu géographique. Nous avons aussi déterminé les isothermes de sorption de ces gommes pour prédire les conditions idéales de leur conservation. Les résultats obtenus à l'issue de cette étude ont démontré clairement la présence des corrélations morphologie, composition chimique et coordonnées géographiques de différents cultivars étudiés. De même, les études structurales et rhéologiques ont montré des différences significatives entre les gommes purifiées. Cette différence semble être liée à une variation du rapport galactose/mannose et de la masse molaire observée selon les variétés. Par ailleurs, les études des isothermes de sorption ont permis de fournir des informations complémentaires sur leurs hygroscopicités et par conséquence sur les conditions idéales de leur conservation
Aminoglycosides are used in treating a wide range of infections caused by Gram-positive and Gram-negative bacteria; however, amino-glycoside resistance is common and occurs by several mechanisms. Among these mechanisms is bacterial rRNA methylation by the 16S rRNA methyl transferase (16S-RMTase) enzymes; but data about the spread of this mechanism in Egypt are scarce. Cephalosporins are the most commonly used antimicrobial agents in Egypt; therefore, this study was conducted to determine the frequency of 16S-RMTase among third generation cephalosporin-resistant clinical isolates in Egypt. One hundred and twenty three cephalosporin resistant Gram-negative clinical isolates were screened for aminoglycosides resistance by the Kirby Bauer disk diffusion method and tested for possible production of 16S-RMTase. PCR testing and sequencing were used to confirm the presence of 16S-RMTase and the associated antimicrobial resist-ance determinants, as well as the genetic region surrounding the armA gene. Out of 123 isolates, 66 (53.66%) were resistant to at least oneaminoglycoside antibiotic. Only one Escherichia coli isolate (E9ECMO) which was totally resistant to all tested aminoglycosides, was confirmed to have the armA gene in association with blaTEM-1, blaCTX-M-15, blaCTX-M-14 and aac(6)-Ib genes. The armA gene was found to be carried on a large A/C plasmid. Genetic mapping of the armA surrounding region revealed, for the first time, the association of armA with aac(6)-Ib on the same transposon. In conclusion, the isolation frequency of 16S-RMTase was low among the tested aminoglycoside-resistant clinical samples. However, a novel composite transposon has been detected conferring high-level aminoglycosides resistance.
Alcoholic fermentation of carob waste sugars (sucrose, glucose and fructose) extracted with cheese whey, by co-cultures of Saccharomyces cerevisiae and Kluyveromyces lactis has been analyzed. Growth and fermentation of S. cerevisiae in the carob-whey medium showed an inhibition of about 30% in comparison with water-extracted carob. The inhibition of K. lactis on carob-whey was greater (70%) when compared with the whey medium alone, due to osmolarity problems. Oxygen availability was a very important factor for K. lactis, influencing its fermentation performance. When K. lactis was grown alone on carob-whey medium, lactose was always consumed first, and glucose and fructose were consumed afterwards, only at high aeration conditions. In co-culture with S. cerevisiae, K. lactis was completely inhibited and, at low aeration, died after 3 days; at high aeration this culture could survive but growth and lactose fermentation were only recovered after S. cerevisiae became stationary. To overcome the osmolarity and K. lactis’ oxygen problems, the medium had to be diluted and a sequential fermentative process was designed in a STR–3l reactor. K. lactis was inoculated first and, with low aeration (0.13 vvm), consumed all the lactose in 48 hours. Then S. cerevisiae was inoculated, consuming the total of the carob sugars, and producing ethanol in a fed-batch regime. The established co-culture with K. lactis increased S. cerevisiae ethanol tolerance. This fermentation process produced ethanol with good efficiency (80 g/l final concentration and a conversion factor of 0.4 g ethanol/g sugar), eliminating all the sugars of the mixed waste. These efficient fermentative results pointed to a new joint treatment of agro-industrial wastes which may be implemented successfully, with economic and environmental sustainability for a bioethanol industrial proposal.
Biodesulfurization (BDS) process consists on the use of microorganisms for the removal of sulfur from fossil fuels. Through BDS it is possible to treat most of the organosulfur compounds recalcitrant to the conventional hydrodesulfurization (HDS), the petroleum industry's solution, at mild operating conditions, without the need for molecular hydrogen or metal catalysts. This technique results in lower emissions, smaller residue production and less energy consumption, which makes BDS an eco-friendly process that can complement HDS making it more efficient. BDS has been extensively studied and much is already known about the process. Clearly, BDS presents advantages as a complementary technique to HDS; however its commercial use has been delayed by several limitations both upstream and downstream the process. This study will comprehensively review and discuss key issues, like reduction of the BDS costs, advances and/or challenges for a competitive BDS towards its potential industrial application aiming ultra low sulfur fuels.
Cited By (since 1996):1, Export Date: 18 October 2014
BACKGROUND: Biodesulfurization (BDS) is a complementary technology to hydrodesulfurization since it allows the removal of recalcitrant sulfur compounds present in fossil fuels. The cost of culture medium to produce the biocatalysts is still one limitation for BDS application. Carob pulp, as an alternative carbon source, can reduce this cost. However, the presence of sulfates is critical, since BDS is inhibited at very low concentrations. Thus, the goal of this work was to optimize the process of sulfur precipitation on carob pulp liquor.
RESULT: The effect of BaCl2 concentration (0–0.5%) and exposure time (6–36 h) on sulfate removal from carob pulp liquor was studied according to a statistical design following the Doehlert distribution for two factors. This experimental design determined that 0.5% BaCl2 concentration for 21 h were adequate conditions for sulfate removal from carob pulp liquor using BDS.
CONCLUSION: These results demonstrate that it is possible to use alternative carbon sources derived from agro-industrial wastes for BDS, even thosewith high sulfur levels. For future industrial application, an inexpensive culturemediumwould have to be employed in a large-scale process and carob pulp liquor could be the carbon source.
Postharvest decay in harvested fruit causes considerable economical losses. Fungicides are the primary means to control these losses. Public concern in food safety and environmental issues and the increase of pathogen resistant populations have enhanced the interest in developing alternative methods to fungicides to control postharvest fruit decay. During the last two decades a huge information and advances concerning the selection of antagonists, mode of action, different approaches to enhance biocontrol activity, formulation and production have been achieved, and some biofungicides are already in the market. It is likely that several more products will enter the market in the near future, as the result of the biological control research programs worldwide. Nonetheless, it is necessary to continue finding new potential microorganisms, better understanding the mode of action, and pathogen, antagonist and host interactions, to increase the potential of biocontrol helping to become a real alternative to synthetic postharvest fungicides. This article presents an overview of postharvest biological control approaches and explores new research possibilities to improve biocontrol activity.
World trends are moving towards reduced pesticide use in fresh fruit and vege-tables. Along with this trend, several physical and biological means have been eval-uated as safer alternatives for the use of chemical fungicides. The use of microbial antagonists for control of postharvest diseases received special attention, and has been extensively investigated. Most of the reported yeast and bacteria antagonists were naturally occurring on fruit surfaces. Microbial biocontrol agents of postharvest diseases have been criticized mainly for not providing as consistent or broad-spectrum control as synthetic fungicides. The "first generation" of biologi-cal controls for postharvest spoilage relied on the use of single antagonists. Per-haps it is unrealistic for us to expect disease control comparable to synthetic fungicides by the use of single antagonists. It can be expected that enhancing effi-cacy of biocontrol agents of postharvest diseases to an acceptable level will utilize a combination of different biological and physical means. As we learn more about the fundamental basis underlying the protective effect of microbial antagonists, bioactive compounds, and induced resistance, more effective methods of formulat-ing, applying and combining complementary biological approaches for additive and/or synergistic effects will emerge. So far, the results obtained with different combinations of biological, chemical and physical means demonstrate the poten-tial of this multifaceted approach as a viable alternative to synthetic fungicides.
SUMMARY In this study, growth and efficacy of two biological control agents, Pseudomonas fluorescens P-35 and Bacil- lus subtilis B-3, were evaluated in combinations of two carbon (sucrose and molasses) and two nitrogen (urea and yeast extract) sources to optimize control of Botrytis cinerea on apple. Nutrient broth was used as control. Re- sults indicated that the medium containing molasses and yeast extract (MY) in a 1:1 w/w ratio supported rapid growth and high cell yields in both strains. The biocon- trol efficacy of P-35 grown in MY was higher than when grown in the other media, and the percentage of decayed fruits was 38.6% as compared to the control (100%), af- ter ten days incubation. P-35 also showed good biocon- trol efficacy in MY after 20 days. Nutrient broth resulted in poor biocontrol efficacy for B-3 after ten days, as com- pared with the other media. For both strains molasses were a good carbon source in combination with yeast ex- tract, but antagonist growth was decreased when mo- lasses were complemented with urea. The results ob- tained could provide a reliable basis for mass multiplica- tion of biocontrol agents in fermentation processes.
Losses are generally determined at a single point in the postharvest food pipeline and accumulated losses while food is being transported and processed are seldom calculated. We fail to consider postharvest disease losses in grocery stores, restaurants, fast food outlets, and kitchens. Also, losses in the nutritional value and quality of food are generally overlooked. In less de veloped countries, postharvest losses are even greater because of the lack of adequate refrigeration and poor sanitation. Worldwide, postharve st losses have been estimated to be 50% of the harvested crop (20) and much of this is due to rots caused by microorganisms. Fungicides are a primary means of controlling postharvest diseases (26) and they have recently come under special scrutiny as posing potential oncogenic risks when applied to processed foods. A 1987 U.S. National Academy of Sciences (NAS) report (41a) states, "As a class the fungicides present special difficulties because nine oncogenic compounds account for about 90% of all fungicide sales." The report indicates that fungicides constitute 60% of the
Total mass transfer coefficients of soluble solids (SS) and total phenolic compounds (TPC) were determined during carob extraction. The Arrhenius equation was applied to determine the efficiency of process temperature, as an alternative approach to Fick's second law. Carob pod, cut into small pieces (internal diameter: 5–7 mm), was contacted with water in batch system to extract SS by continuous circulation of water at different temperatures (20, 50 and 85C). The process was also performed at 85C using an industrial-scale extractor. Activation energies for both SS and TPC diffusions were calculated as 5.84 and 0.072 × 10−3 kJ/mol, respectively. As expected, higher extract concentrations were achieved with higher temperatures. In contrast, high extraction temperature, even at 85C, did not cause hydroxymethylfurfural (HMF) formation. As the increase in temperature does not affect formation of HMF during carob pod extraction, higher operational temperatures such as 80–90C may be applied to obtain higher solute concentrations.
Carob-tree (Ceratonia siliqua L.) is a sclerophyllous leguminous tree species widely cultivated in whole Mediterranean basin. The fruits (a dry pod) are normally used after crushing to separate seed and pulp, and the seed endosperm is processed to obtain a mucilaginous gum, which is then used in a wide range of commercial food products as a thickener and stabilizer. Contrary to other traditional crops, there is an increasing demand for carob products, which represents a potential benefit to farmers and a diversification of farm incomes. However, current information about the ecology of this crop has not yet been integrated and so there are some doubts about the correct management of natural resources, like water and soil nutrients, in order to improve productivity. These items are particularly important in Mediterranean areas where growth and yield are mostly limited by both climatic and edaphic conditions. In this short communication, some data concerning water and nutrients use (particularly nitrogen) in carob-tree are reviewed.
The possibility of utilising chopped and deseeded carob pods (kibbles) as a source of polyphenolic antioxidants was examined by performing extractions with various solvent systems, in order to evaluate and optimize the conditions for the recovery of polyphenols. Maximum quantities of polyphenolic components were found in 80 % acetone extracts, as evaluated by measuring total polyphenol and total flavanol content. By contrast, ethyl ace-tate was inefficient in extracting polyphenols. The assessment of the antioxidant potency of carob pod extracts employing two characteristic in vitro models showed that carobs con-tain polyphenols with appreciable antiradical and reducing properties. The values obtained were compared to the data on red wines and pure polyphenolic antioxidants.
Spores of Fusarium flocciferum were inserted in porous celite beads. The effects of bead size, adsorption time course, washing cycle and spore concentration on spore loading were investigated. Cell loadings up to 50% (dry weight/beads) were obtained. The degradation of phenol using adsorbed cells was studied in batch experiments. The immobilized cell system was shown to efficiently degrade high concentrations of the substrate (up to 2.0 g/l) and to remain active for more than 2 motths. The oxygen uptake rate of free and immobilized cells was determined at various concentrations of phenol. The kinetic constants K
s=85 mg/l, K
i=345 mg/l and SMI=170 mg/l were estimated from the experimental data by linearization of the Haldane function for the free cells. The uptake rates exhibited by the confined cells were lower (30%) than those obtained for free cells and no significant differences were found for phenol concentrations between 150 and 1200 mg/l.
Lactic acid was produced by Rhizopus arrhizus using waste potato starch as the substrate. The aim of this study was to identify the role of nitrogen sources and their
impact on the formation of lactic acid and associated byproducts. Ammonium sulphate, ammonium nitrate, urea, yeast extract
and peptone were assessed in conjunction with various ratios of carbon to nitrogen (C:N). Fermentation media with a low C:N
ratio enhanced the production of lactic acid, biomass and ethanol, while a high C:N ratio favoured the production of fumaric
acid. Ammonium nitrate appeared to be the most suitable nitrogen source for achieving a high and stable lactic acid yield,
and minimizing the production of byproducts such as biomass and ethanol, while urea proved to be the least favourable nitrogen
source. Yeast extract and peptone appeared to improve fungal cell growth. The kinetics data revealed that a high concentration
of ammonium nitrate enhanced the lactic acid productivity. The maximum lactic acid concentration of 36.4g/l, representing
a yield of 91%, was obtained with addition of 0.909g/l ammonium nitrate in 32h.
Carob pod, germ, and seed were analyzed for moisture, ash, protein, fat, carbohydrates, and particularly for their tannin content. Recovery of tannins as affected by various solvent extraction systems was investigated. Carob pod meal contained high levels of carbohydrates (45%), appreciable amounts of protein (3%), and low levels of fat (0.6%). Germ and seed meal contained more fat and less carbohydrates compared to the carob pod. Seventy percent acetone was the most effective solvent for the extraction and recovery of tannins. Carob pod contains a mean value of 19 mg of total polyphenols/g, 2.75 mg of condensed tannins (proanthocyanidins)/g, 0.95 mg of hydrolysable tannins (gallo- and ellagitannins)/g. Germ contained higher concentration of total polyphenols (40.8 mg/g) and tannins (16.2 mg of condensed tannins/g and 2.98 mg of hydrolysable tannins/g) while only traces of these compounds were detected in carob seed.
The possibility of processing roasted carob powder using different time–temperature combinations has been studied. The physical and chemical characteristics of the prepared carob powders were also examined. The most acceptable roasted carob powder was obtained by roasting kibbled carob at 150°C for 60 min. The roasted carob powder contained 9.00, 5.82, 2.84 and 0.74% moisture, protein, ash and fat, respectively. The carob powder had 38.7% total sugar, 7.24% fiber and 3.75% tannins. The powder had a pH of 4.81, its water activity was 0.33 and its particle size was 150 μm.
ABSTRACT Biocontrol agents may compete with pathogens for nutrients and space to delay or prevent decay of fruits after harvest. These mechanisms of biological control have been difficult to study because no method has been available to determine the significance of each of the components of competition. We developed a nondestructive method using tissue culture plates with cylinder inserts containing defusing membrane at one end to study competition for nutrients without competition for space. Other biocontrol mechanisms in which direct contact between an antagonist and a pathogen is not required also can be studied. The method was used to determine the competition between the yeastlike biocontrol agent, Aureobasidium pullulans, and Penicillium expansum for limited nutrients in apple juice during 24 h incubation, simulating a fruit wound. The antagonist depleted amino acids and inhibited germination of P. expansum conidia. Exposing these conidia to fresh apple juice increased conidial germination to the level comparable to that exhibited by conidia which were not exposed to the antagonist. Because the culture plate method was nondestructive, follow-up experiments in an agar diffusion test were conducted. Juice in which the antagonist grew did not inhibit germination of P. expansum conidia that were seeded on the plates. This corroborates findings from the culture plate method that inhibition of the conidia germination resulted from competition for nutrients. The new method can be coupled with existing techniques to improve understanding of antagonist-pathogen interaction for biological control of postharvest diseases.
ABSTRACT Strains of Pantoea agglomerans (synanamorph Erwinia herbicola) suppressed the development of basal kernel blight of barley, caused by Pseudomonas syringae pv. syringae, when applied to heads prior to the Pseudomonas syringae pv. syringae infection window at the soft dough stage of kernel development. Field experiments in 1994 and 1995 revealed 45 to 74% kernel blight disease reduction, whereas glasshouse studies resulted in 50 to 100% disease control depending on the isolate used and barley cultivar screened. The efficacy of biocontrol strains was affected by time and rate of application. Percentage of kernels infected decreased significantly when P. agglomerans was applied before pathogen inoculation, but not when coinoculated. A single P. agglomerans application 3 days prior to the pathogen inoculation was sufficient to provide control since populations of about 10(7) CFU per kernel were established consistently, while Pseudomonas syringae pv. syringae populations dropped 100-fold to 2.0 x 10(4) CFU per kernel. An application to the flag leaf at EC 49 (before heading) also reduced kernel infection percentages significantly. Basal blight decreased with increasing concentrations (10(3) to 10(7) CFU/ml) of P. agglomerans, with 10(7) CFU/ml providing the best control. For long-term preservation and marketability, the survival of bacterial antagonists in several wettable powder formulations was tested. Over all formulations tested, the survival declined between 10- to >100-fold over a period of 1.5 years (r = -0.7; P = 0.000). Although not significant, storage of most formulations at 4 degrees C was better for viability (90 to 93% survival) than was storage at 22 degrees C (73 to 79%). However, long-term preservation had no adverse effect on biocontrol efficacy.
Losses from postharvest fruit diseases range from 1 to 20 percent in the United States, depending on the commodity. The application of fungicides to fruits after harvest to reduce decay has been increasingly curtailed by the development of pathogen resistance to many key fungicides, the lack of replacement fungicides, negative public perception regarding the safety of pesticides and consequent restrictions on fungicide use. Biological control of postharvest diseases (BCPD) has emerged as an effective alternative. Because wound-invading necrotrophic pathogens are vulnerable to biocontrol, antagonists can be applied directly to the targeted area (fruit wounds), and a single application using existing delivery systems (drenches, line sprayers, on-line dips) can significantly reduce fruit decays. The pioneering biocontrol products BioSave and Aspire were registered by EPA in 1995 for control of postharvest rots of pome and citrus fruit, respectively, and are commercially available. The limitations of these biocontrol products can be addressed by enhancing biocontrol through manipulation of the environment, using mixtures of beneficial organisms, physiological and genetic enhancement of the biocontrol mechanisms, manipulation of formulations, and integration of biocontrol with other alternative methods that alone do not provide adequate protection but in combination with biocontrol provide additive or synergistic effects.
Populations of Botrytis spp., Penicillium spp., and Mucor piriformis were determined during two seasons in air and dump-tank water of nine apple and pear packinghouses. Populations of all fungi varied considerably among packinghouses. Spores of Penicillium spp. were more abundant in air and dump water than spores of Botrytis spp. or M. piriformis. Spores of Penicillium spp. and M. piriformis in dump water increased as the packing season progressed, suggesting that decaying fruit stored in bins and processed later in the season increased propagule levels more than did debris brought into packinghouses from orchards early in the season. Selected isolates were characterized for pathogenicity and virulence on Anjou pear fruit and resistance to benomyl. Sixty, 72, and 89% of Botrytis spp., Penicillium spp., and M. piriformis isolates, respectively, were pathogenic on pear fruit. The percentage of pathogenic Penicillium spp. isolates resistant to benomyl also increased later in the season. Benomyl-resistant isolates of Penicillium spp. were less virulent than benomyl-sensitive isolates. The percentage of Penicillium spp. isolates resistant to benomyl in the Mid-Columbia region has not increased during the last 5 yr.
The cotton bollworm, Helicoverpa armigera, is the most damaging cotton pest in West Africa. To control this pest in sub-Saharan Africa, only chemical sprayings are applied. These include a combination of a pyrethroid for the control of bollworms and an organophosphate to control other members of the pest complex and to enhance the effectiveness of pyrethroid against bollworms. Intensive use of these chemical insecticides against H. armigera has led to the development of resistance to the major chemical families of insecticides. This paper reviews the research work aimed at controlling H. armigera by using parasitoids, predators, micro-organisms, plants extracts as well as other environmentally-friendly compounds, for their possible use against H. armigera on cotton, as part of a pyrethroid resistance management strategy in West Africa. It also includes research work on kaolin formulation as crop protectant.
Carob pods contain about 200–500 g/kg of total sugars, a higher content of sugar than is present in beet or cane, which is below 200 g/kg. In the present paper a sugar syrup (concentrate solution of several sugars) from carob pods has been obtained with a concentration of sugars near 580 g/kg, 62° Brix and 93% of purity. Extraction and purification techniques were performed. From the results of the extraction researches it can be concluded that a 10 column system connected in series is the most advantageous for efficiency and automation of the sugar extraction reaching a yield of at least 90%. In the purification technique a discontinuous treatment followed by purification in several types of columns connected in series have been studied in order to obtain a transparent and colourless extract.
The production of ethanol from non-sterilized beet molasses by free and immobilized S. cerevisiae cells in batch and fed-batch culture was investigated. Fed-batch culture proved to be a better fermentation system for the production of ethanol than batch culture. In fed-batch culture, both free and immobilized S. cerevisiae cells gave the same maximum ethanol concentration (53 g/litre) at an initial sugar concentration of 250 g/litre and F = 250 ml/h. In the free cells system, the maximum ethanol productivity (3.8 g/litre h) was obtained at a substrate concentration of 250 g/litre and F = 500 ml/h with 30.6% ethanol yield and 81% sugars utilization. In the immobilized cells system, a maximum ethanol productivity of 3.5 g/litre h was achieved at an initial sugar concentration of 250 g/litre and F = 500 ml/h with 31.2% ethanol yield and 73.3% sugars utilization. In repeated fed-batch culture, immobilized S. cerevisiae cells gave higher overall ethanol concentration compared to the free cells. In this case, the immobilized S. cerevisiae cells in Ca-alginate beads retained their ability to produce ethanol for 8 days.
Worldwide, postharvest losses of fruits and vegetables are estimated at more than 25%, and much of this is due to postharvest decay. This chapter provides an overview of the potential application, and limitations of microbial antagonists to prolong shelf-life, and control of decay of harvested commodities. Biocontrol products are expected to protect wounds from being infected during processing, deactivate wound infection occurring during the harvesting process, and this protection must last during storage, shipping and retailing phase. If, we are to maximize the biocontrol potential of microbial antagonists, a more fundamental understanding of their mode of action, their ecology, their compatibility with postharvest commercial practices, and the effect of host physiology on their biological activity is needed. Several other promising biological control approaches that include the use of bioactive compounds and induced resistance are available and can be used in combination with microbial antagonists to provide a greater stability and effectiveness than the approach of utilizing a single microbial biocontrol agent.
Two multistage methods of sugar extraction from carob pods were compared with a single stage extraction/pressing process. A multistep extraction/pressing process produced a yield improvement of 6·6%. A second process based on the recycling of press liquor through a multistage series of vessels was not only considerably simpler and more economical in use of labour but also showed a further improvement of 1·4% to give a final sugar yield of 60%.A comparison of the calculated diffusion coefficients showed that the enhanced yield in the recycle flow process resulted from a decrease of a diffusion limitation observed in static operation. A diffusion coefficient of 9·9 × 103 m2/h was obtained at the highest yield.
Indoor studies were conducted to determine the potential use of Pantoea agglomerans isolate LRC 8311 as a biocontrol agent for control of bacterial wilt of bean caused by Curtobacterium flaccumfaciens pv. flaccumfaciens. Soaking seeds of great northern bean cv. US1140 in a suspension of 3 × 108 cfu/ml P. agglomerans resulted in thorough endophytic colonization of the entire bean seedling from root to apical stem after 7 days, regardless of whether the inoculated seeds were hilum injured or not. Colonization of seedlings by P. agglomerans increased seedling height after 10 days, and had no negative effect on seedling emergence. Treatment of hilum-injured bean seeds of great northern bean cv. US1140 or navy bean cv. Morden003 with a mixture of P. agglomerans + C. flaccumfaciens pv. flaccumfaciens resulted in a high rate of colonization of seedlings by P. agglomerans, reduced frequency of infection by C. flaccumfaciens pv. flaccumfaciens, improved seedling emergence and height, and reduced disease severity, compared with seeds treated with the wilt pathogen alone. Application of P. agglomerans as a soil drench 24 h after planting was also effective in suppressing bacterial wilt in some instances, but was generally not as effective as seed treatment. The study suggests that seed treatment with P. agglomerans may be an effective and practical method for control of bacterial wilt of bean.
Seventy-nine cocoa or chocolate products and eighteen carob products were analyzed by HPLC for caffeine and theobromine content. After extraction into boiling water, the methylxanthines were identified and quantified with the use of a reverse phase column. Mean theobromine and caffeine levels respectively, were 0.695 mg/g and 0.071 mg/g in cocoa cereals; 1.47 mg/g and 0.152 mg/g in chocolate bakery products; 1.95 mg/g and 0.138 mg/g in chocolate toppings; 2.66 mg/g and 0.208 mg/g in cocoa beverages; 0.621 mg/g and 0.032 mg/g in chocolate ice creams; 0.226 mg/g and 0.011 mg/g in chocolate milks; 74.8 mg/serving and 6.5 mg/serving in chocolate puddings. Theobromine and caffeine levels in carob products ranged from 0-0.504 mg/g and 0-0.067 mg/g, respectively.
The aim of the study was to determine the main sugar profiles of the pods, without the seeds, of cultivated and wild types of the carob bean grown in the Mediterranean and Aegean basin of Turkey. The most abundant sugar in the pods was sucrose with smaller amounts of glucose and fructose. The pods of cultivated varieties had a higher (p < 0.05) total sugar concentration of 531 ± 93 g/kg dry weight than the wild type selections which had 437 ± 77 g/kg. However, this difference was due to the greater concentration of sucrose in the cultivated varieties which did not differ from the wild types in their concentrations of fructose or glucose. The ratios of individual sugars to total sugars in the pods were similar in both varieties. There is a need to identify extreme wild types, including high seeds and low pod, and cultivated types, containing low seeds and high pod, rich in sugar for an exhaustive picture of the sugar profiles of the varieties.
Concerns about food safety as well as the development of resistance to many fungicides by major postharvest pathogens have
increased recently. Biological control, using microorganisms antagonistic to the fungal plant pathogens, appears to be promising
as an alternative to fungicides. The microbial biocontrol agent has to be produced on an industrial scale, maintaining its
biocontrol efficacy. The purpose of the current study was to optimize the conditions for microbial biomass production of the
biocontrol agent Pantoea agglomerans PBC-1 in a 2-l mechanically stirred reactor (STR), defining mixing and mass transfer technological parameters and the growth
kinetics for different saccharides. In the batch mode, different impellers and spargers were tested. Despite the oxygen mass
transfer improvement achieved with marine propeller combined with porous sparger, the biomass did not increase, if compared
with the use of a Rushton turbine and L-sparger, pointing out the relevance of a radial flux for better broth homogenization.
Different carbon sources were used: sucrose, glucose and fructose; each of which led to viable populations 3.9×109, 1.4×109, 3.9×109c.f.u/ml, respectively, after 20h of incubation. Fed-batch technology allows the maintenance of high cell viability for
longer periods of time in the stationary growth phase, which can be crucial for the scale-up of biocontrol agent production
process that is achieved together with a reduction of 85% on the incidence caused by the pathogens, brought about by fresh
microbial biomass preparation on artificially wounded apples or oranges, stored for 7days at 25°C against Penicillium expansum and Penicillium digitatum.
KeywordsBatch culture-Fed-batch culture-Mixing-Mass transfer-Cell growth-Stirred bioreactor-Biocontrol agent-
Pantoea agglomerans
Postharvest diseases on citrus and pome fruits are generally controlled by chemical treatments applied in packinghouses before fruit storage. However, there are some points that make pre-harvest strategies interesting practices to control or reduce postharvest rots. (a) Field practices and fruit manipulation in general can play an important role in fruit susceptibility in front postharvest diseases. (b) In some cases, infection of fruit occurs in the field prior to harvest and it could be advantageous starting control at this point. (c) Pre-harvest strategies also decrease fruit manipulation and subsequently potential damages and injuries, which are necessary for some important fungi infection. (d) Additional contamination by pathogenic fungi present in drenching solutions used in packinghouses would also be avoided. Twelve years of research have allowed us to study different approaches and some of them are summarized in this chapter.
The aim of this research was to enhance efficacy of preharvest biocontrol treatments using different strategies: combination of biocontrol agents, combination with low-risk substances such as ammonium molybdate, and finally increase environmental stress tolerance of biocontrol agents. All these experiences have let to conclude that pre-harvest practices can play an important role in postharvest disease control.
There are several reasons of the limited number of commercial available biocontrol agents, such as the difficulties in developing a shelf-stable formulated product that retains biocontrol activity. This chapter shows that it is possible to improve the formulations during the production process and describes several examples of improving liquid and dry formulations using different strategies such as grow microorganisms in a
w modified media, under sublethal thermal stress conditions or preservation in isotonic solutions.
Liquid formulation of C. sake was improved growing the cells in molasses medium with a
w modified to 0.98 with the addition of sorbitol and preserved with an isotonic trehalose solution. After 180 days of storage at 4°C, the viability of this formulate was 100% and the efficacy against Penicillium expansum on apples was more than 95% rot reduction.
Spray drying formulations were improved by modifying growth media or temperatures during growing period. The biocontrol agent Pantoea agglomerans grown during 48 h in NaCl 0.97 a
w modified medium could increase their viability after spray drying formulation from 6% in unmodified medium to near 30% without affecting their biocontrol potential.
In contrast Candida sake cells grown in unmodified molasses medium exposed to mild heat treatments at 30°C or 33°C during mid or late-exponential or early or mid-stationary growth phases showed an increase of survival when are exposed to lethal shock at 40°C, but only a very reduced improvement after spray drying formulation.
Finally the combination of thermal and osmotic stress was studied in order to improve fluidized bed drying formulations of P.agglomerans. The results showed than using NaCl to adjust a
w to 0.988 in the growth medium and increasing the temperature to 35°C during 1 h in the early stationary phase could get a good formulate with only 0.5 log reductions during fluidized bed drying process.
Axenic cultivation of biocontrol fungus Trichoderma viride was conducted on a synthetic medium and different wastewaters and wastewater sludges in shake flasks to search for a suitable
raw material resulting in higher biocontrol activity. Soluble starch based synthetic medium, dewatered municipal sludge, cheese
industry wastewater sludge, pre-treated and untreated pulp and paper industry wastewater and slaughter house wastewater (SHW)
were tested for T. viride conidia and protease enzyme production. The maximum conidia production followed the order, soluble starch medium (>109c.f.u./mL), untreated pulp and paper industry wastewater (4.9×107c.f.u./mL)>cheese industry wastewater (1.88×107c.f.u./mL)≈SHW (1.63×107c.f.u./mL)>dewatered municipal sludge (3.5×106c.f.u./mL)>pre-treated pulp and paper industry wastewater (1.55×106c.f.u./mL). The protease activity of T. viride was particularly higher in slaughterhouse wastewater (2.14IU/mL) and dewatered municipal sludge (1.94IU/mL). The entomotoxicity
of soluble starch based synthetic medium was lower (≈6090SBU/μL) in contrast to other raw materials. The entomotoxicity inversely
decreased with carbon to nitrogen ratio in the growth medium and the conidia concentration and protease activity also contributed
to the entomotoxicity. The residual c.f.u./g formulation of T. viride conidia were up to approximately, 90% after 1month at 4±1°C and about 70% after 6months at 25±1°C. Thus, production
of T. viride conidia would help in marketability of low cost biopesticide from the sludge and safe reduction of pollution load.
Carob pod is the fruit of the carob tree ( Ceratonia siliqua L. Fabaceae). The fruit and its products, sold both in large stores and local markets, contribute strongly to the diet of people living in the Mediterranean areas of Europe and Turkey. This study reports the composition of carob pods sampled in West and South Anatolia. Sucrose (437.3 mg/g dry weight), glucose (395.8 mg/g dry weight) and fructose (42.3 mg/g dry weight) were the major sugars identified and quantified in the fruit. Total phenolics (13.51 mg gallic acid equivalents [GAE]/g dry weight), proanthocyanidin (0.36 mg GAE/g dry weight), gallotannins (0.41 catechin equivalents [CE]/g dry weight) and flavanols (3.21 mg CE/g dry weight protein) content of the fruit were also determined. Gallic acid (3.27 mg/g dry weight) was the most abundant phenolic acid present in all three phenolic fractions (free, ester and glycoside) isolated from pods. Aspartic acid (18.25 mg/g dry weight protein) was the predominant amino acid in the pod protein fraction. Eight minerals were quantified in the fruit. Among the analyzed major minerals, K (9.70 mg/g dry weight) was the most abundant element present, and the pods were richer in Ca than in P and Mg. Levels of trace minerals were comparable to other plant species. The data are discussed in terms of the nutritional value of the carob pod.
PRACTICAL APPLICATION
The use of carob fruit and its food products in Turkey has been increasing in recent years. However, knowledge about the composition of carob fruit pod produced in Turkey as well as in Mediterranean countries is lacking. The present work describes a composition scale and the advantages to food technologists and consumers who use the fruit and its fruit products in their diets. The results of the study can also aid in the assessment of adequate compositional information for further studies.
Absorption of gases into a liquid is essentially important for two- or three-phase reactions, because the diffusion of a sparingly soluble gas, like oxygen, across a gas–liquid interface generally limits the reaction rates. Using a third, dispersed phase, the mass transfer rate could be significantly increased. The question arises how the absorption rate can be described in the presence of very fine, nanometer size particles or droplets. Its mathematical model should take into account the specific properties of the nanoparticles, e.g. the Brownian motion of particles, its effect on the diffusion of the bulk phase molecules, the mass transfer rate into the nanoparticles, its dependency on the particle size, etc. The mass transfer rate of oxygen, in the presence of nanometer size, organic droplets, has been investigated both experimentally, using organic submicron n-hexadecane droplets, and theoretically. The effect of the Brownian motion of the nanoparticles as well as its effect on the diffusivity in the nanofluid has been discussed. Accordingly, the enhanced diffusion coefficient, due to the convective motion of the continuous liquid phase induced by the moving particles, has been predicted and its effect on the mass transfer enhancement has been calculated using both homogeneous and heterogeneous mathematical models. The predicted data were compared to the measured ones.
A collection of 282 bacterial isolates from the rhizosphere and different organs of healthy field-grown grapevine plants was obtained and screened for their ability to protect grapevine leaves against Botrytis cinerea, the causal agent of gray mold. Twenty-six strains effectively controlled B. cinerea infections on leaves. After phenotypic and molecular analysis, seven strains were identified as Pseudomonas fluorescens PTA-268 and PTA-CT2, Bacillus subtilis PTA-271, Pantoea agglomerans PTA-AF1 and PTA-AF2, and Acinetobacter lwoffii PTA-113 and PTA-152. In vitro antifungal experiments showed that from these seven strains, only PTA-AF1 and PTA-CT2 exhibited a direct antagonism against B. cinerea. Furthermore, the biocontrol activity of the seven bacteria was associated with differential induction of defense-related responses lipoxygenase, phenylalanine ammonia-lyase and chitinase in grapevine leaves. Our results show that the selected bacteria can efficiently protect grapevine leaves against gray mold disease through an induction of plant resistance and in some cases by an additional antagonistic activity.
In this work, an empirical correlation is proposed to describe kLa as a function of operating conditions (agitation and aeration rates) and of oil and surfactant volumetric fractions in a biotransformation medium, an oil-in-water dispersion. An interaction effect between the oil and the surfactant effects was found, since oil presence increased kLa in the absence of the surfactant but had an opposite effect when Tween 80 was available in the medium. The biotransformation of methyl ricinoleate (MR) into γ-decalactone (an aroma compound of industrial interest), by the yeast Yarrowia lipolytica, was carried out at different conditions of operation, to evaluate the influence of kLa on the production of the aroma. It was demonstrated that kLa had an influence on the aroma production; however, for the low hydrophobic substrate concentration used (1.08% v/v) and cellular density of 2.0 × 107 cells mL−1, a minimal kLa value of 70 h−1 was necessary to attain the maximal aroma production.
The use of biocontrol agents as an alternative to synthetic, chemical fungicides that are presently used to control postharvest pathogens, has many constraints and obstacles that make it difficult to implement their use as a practical control strategy. Over the last 20 years postharvest biocontrol research has evolved towards being more integrated into a production systems approach with greater awareness of industry concerns. More research, however, is needed in many aspects of the science and technology of postharvest biocontrol and in integrating biocontrol agents into combined pre- and postharvest production and handling systems. Better understanding of the mode of action of postharvest biocontrol agents, relationships between infection levels occurring in the field and development of postharvest decay, along with basic information on microbial ecology and survival mechanisms of biocontrol agents on fruit surfaces, is critical for the advancement of successful implementation of postharvest biocontrol technology. The past 20 years of postharvest biocontrol research has seen tremendous advances and the creation of several products. Nonetheless, numerous challenges and opportunities still exist as this field of research matures. This review is an attempt to examine the field of postharvest biocontrol as it has developed over the past 20 years, define the reasons that have limited its commercialization, and identify areas of research that need to be addressed if the potential of postharvest biocontrol is to be achieved. We have also introduced a new paradigm for biocontrol research that may provide new opportunities for increasing the efficacy and consistency of biocontrol products.
The production of dextran and fructose from carob pod extract (CPE) and cheese whey (CW) as carbon source by the bacterium Leuconostoc mesenteroides was investigated. The influence of secondary carbon sources (maltose, lactose and galactose) on dextran molecular weight and fermented broth viscosity were also studied.Significant changes were not observed in broth viscosity during dextran production at initial sucrose concentration of 20 and 120 g/l. Complementary sugars maltose, lactose and galactose together with sucrose promote production of dextran with fewer glucose units. Dextran molecular weight decreases from the range 1,890,000–10,000,000 to 240,000–400,000 Da when complementary sugars are present. Polydispersity was improved when complementary sugars were used.Fermentation using mixtures of carob pod extract and cheese whey confirm these results obtained for production of dextran. Final concentrations of dextran and fructose indicate that reaction yields were not affected. Carob pod and cheese whey can be successfully used as raw material in the fermentation system described.The maximum concentrations of dextran and fructose obtained using carob pod extract resulted in 8.56 and 7.78 g/l, respectively. Combined carob pod extract and cheese whey resulted in dextran and fructose concentrations of 7.23 and 6.98 g/l, respectively. The corresponding dextran mean molecular weight was 1,653,723 and 325,829.
The production of citric acid from carob pod by Aspergillus niger in solid-state fermentation was investigated. The maximal citric acid concentration (176 ± 4 g kg−1 dry pod), biomass dry weight (30 ± 0.7 g kg−1 wet substrate), citric acid yield (55 ± 2%), and sugar utilization (64 ± 2.5%) were obtained at a particle size of 0.5 mm, moisture level of 65%, pH of 6.5, and temperature of 30°C. The addition of 6% (w/w) methanol into the substrate increased the concentration of citric acid from 176 to 264 g kg−1 dry pod.
The possibility of using waste Chinese cabbage as a substrate for microbial biomass production was investigated. Cell mass and the protein content of four species of yeast, Candida utilis, Pichia stipitis, Kluyveromyces marxianus, and Saccharomyces cerevisiae, were determined when cultured in juice extracted from cabbage waste. Compared to YM broth containing the same level of sugar, all the strains except C. utilis showed higher total protein production in cabbage juice medium (CJM). Cell mass production was lower for all four strains in heat-treated CJM than in membrane-filtered medium, and this adverse effect was pronounced when the CJM was autoclaved at 121°C for . As a source of inorganic nitrogen, only ammonium sulfate added at a concentration of nitrogen per liter of CJM increased cell growth. Of the seven organic nitrogen sources tested, only corn steep powder was effective in increasing cell mass (by about 11%). As a micronutrient, the addition of zinc increased cell mass. The results suggest that juice from waste Chinese cabbages can be used to produce microbial biomass protein without substantial modification, after preliminary heat treatment at temperatures below those required for sterilization.
Oxygen-transfer enhancement has been observed in the presence of colloidal dispersions of magnetite (Fe3O4) nanoparticles coated with oleic acid and a polymerizable surfactant. These fluids improve gas-liquid oxygen mass transfer up to 6-fold (600%) at nanoparticle volume fractions below 1% in an agitated, sparged reactor and show remarkable stability in high-ionic strength media over a wide pH range. Through a combination of experiments using physical and chemical methods to characterize mass transfer, it is shown that (i) both the mass transfer coefficient (k(L)) and the gas-liquid interfacial area (a) are enhanced in the presence of nanoparticles, the latter accounting for a large fraction of the total enhancement (80% or more), (ii) the enhancement in k(L) measured by physical and chemical methods is similar and ranges from 20 to 60% approximately, (iii) the enhancement in k(L) levels off at a nanoparticle volume fraction of approximately 1% v/v, and (iv) the enhancement in k(L)a shows a strong temperature dependence. These results are relevant to a wide range of processes limited by the mass transfer of a solute between a gas phase and a liquid phase, such as fermentation, waste treatment, and hydrogenation reactions.
In aerobic bioprocesses, oxygen is a key substrate; due to its low solubility in broths (aqueous solutions), a continuous supply is needed. The oxygen transfer rate (OTR) must be known, and if possible predicted to achieve an optimum design operation and scale-up of bioreactors. Many studies have been conducted to enhance the efficiency of oxygen transfer. The dissolved oxygen concentration in a suspension of aerobic microorganisms depends on the rate of oxygen transfer from the gas phase to the liquid, on the rate at which oxygen is transported into the cells (where it is consumed), and on the oxygen uptake rate (OUR) by the microorganism for growth, maintenance and production.
The aim of this paper was to find the nitrogen and carbon sources that provide maximum biomass production of strain CPA-2 of the biocontrol agent Pantoea agglomerans and minimum cost of media, whilst maintaining biocontrol efficacy. To reduce the cost of media, commercial products and by-products were tested. P. agglomerans can be produced using a combination of nitrogen sources such as yeast extract (5 g l(-1)) and dry beer yeast (10 g l(-1)) with inexpensive carbohydrates such as sucrose (10 g l(-1)) and molasses (20 g l(-1)), respectively, maintaining the efficacy of the biocontrol agent against Penicillium digitatum and P. italicum on oranges. The results obtained in this study could be used to provide a reliable basis for a scale-up of this fermentation process to an industrial level.