Article

Characteristics of biosurfactant produced by Pseudomonas aeruginosa S6 isolated from oil-containing wastewater

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Abstract

A biosurfactant-producing strain S6 was isolated from oil-containing wastewater and identified as Pseudomonas aeruginosa based on physiological and biochemical tests together with 16S rDNA sequence analysis. Thin layer chromatography (TLC) and high-performance liquid chromatography electrospray ionization mass spectra (HPLC-ESI-MS) worked together to reveal that the strain S6 produced rhamnolipid biosurfactant. Mass spectrometry confirmed the presence of some major components in the rhamnolipid surfactant showing m/z of 675.8, 529.6, 503.3 and 475.4, which corresponded to RhaRhaC10C12:1, RhaC12:1C10, RhaC10C10 and RhaC8C10, respectively. The biosurfactant produced by strain S6 had the ability to decrease the surface tension of water from 72 to 33.9 mN m−1, with the critical micelle concentration (CMC) of 50 mg L−1. Emulsification experiment indicated that this biosurfactant effectively emulsified the crude petroleum and the measurements of surface tension demonstrated that the biosurfactant possessed stable surface activity at variable ranges of pH and salinity. The biosurfactant also exhibited good performance of phenanthrene solubilization with about 23 times higher solubility of phenanthrene in water than the control. Thus, this biosurfactant may have a potential for application in bioremediation of crude oil contamination.

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... The RL was further extracted using the method as proposed by Yin et al. [39]. The supernatant was mixed with ethyl acetate (Merck, Germany) at a ratio of 1:1 and vigorously shook for 3 minutes. ...
... Rhamnolipids comprise one or two β-hydroxy fatty acids of varying chain lengths (C8-C22) linked to one or two rhamnose rings [39]. Common RL congeners (i.e., substance structurally related to RL by origin and function) include di-RL, α-l-rhamnopyranosyl-α-l-rhamnopyranosyl-β-hydroxyd ecanoyl-β-hydroxydecanoate (RhaRha C10C10) and RhaRhaC10, as well as mono-RL homologs, RhaC10 and RhaC10C10. ...
... Common RL congeners (i.e., substance structurally related to RL by origin and function) include di-RL, α-l-rhamnopyranosyl-α-l-rhamnopyranosyl-β-hydroxyd ecanoyl-β-hydroxydecanoate (RhaRha C10C10) and RhaRhaC10, as well as mono-RL homologs, RhaC10 and RhaC10C10. Other homologs were found to be present within the m/z range of 475-677 depending on the number of rhamnose ring, fatty acid chain, and carbon [39]. ...
Article
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The biodegradability and biocompatibility of polyhydroxyalkanoate (PHA) bioplastic and rhamnolipid (RL) biosurfactant have encouraged their application in medicine, packaging, and bioremediation. However, the resources used to produce these two substances contribute to high manufacturing costs. Therefore, we applied the dual-production approach and fed the same renewable and economical carbon and nitrogen sources into singular cultivation media to produce both PHA and RL simultaneously. By-products from oleochemical (glycerol and glycerine pitch) and sugarcane (molasses and sweet water) industries were used to produce mcl-PHA and RL from Pseudomonas aeruginosa UMTKB-5. Furthermore, we also attempted the introduction of plasmid pBBR-PC1020 into transformant P. aeruginosa UMTKB-5 to produce 20-50% scl-mcl PHA with better properties. The PHA and RL yields were compared between wild-type and transformant strains with the use of seven carbon sources and six nitrogen sources. With glycerol as the carbon source and urea [CO(NH2)2] as the nitrogen source, the wild-type strain had produced the highest amount of PHA and RL at 0.24 ± 0.01 and 2.31 ± 0.01 g/L, respectively. The overall molecular weights (Mw) of the polymers produced ranged from 4 x 105 to 5 x 105 Da. Characterisation analysis on the RL congeners produced were identified as mono- and di-RL.
... En las muestras de suelo contaminado se aislaron bacterias heterótrofas, que utilizan sustratos orgánicos como fuente de carbono y energía, coincidiendo con Deyab [7]. El género Pseudomonas se identificó en las bacterias heterótrofas aisladas, por cuanto estas bacterias son ubicuas y son comúnmente aisladas de suelo [6], agua y sedimentos marinos [17]. ...
... se consideraron degradadores de hidrocarburos de petróleo porque utilizaron el contaminante como fuente de carbono y energía [18]. Estos microorganismos oxidan las fracciones del petróleo, generando ácidos grasos que finalmente son degradados hasta dióxido de carbono y agua [17]. El tiempo mínimo requerido por las bacterias para la utilización del petróleo fue 24 Las bacterias degradadoras de petróleo se utilizan en la biorremediación de ambientes contaminados [10], no obstante, la degradación microbiana es a menudo limitada por problemas de transferencia de masa [20]. ...
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La biorremediación de hidrocarburos de petróleo es favorecida por los biosurfactantes. El objetivo de la investigación fue determinar el rendimiento de surfactantes producidos por Pseudomonas spp. degradadoras de hidrocarburos de petróleo. Se colectaron muestras de suelo contaminado y Pseudomonas spp. se consideraron degradadoras cuando utilizaron el petróleo como fuente de carbono y energía. Las bacterias productoras de surfactantes se seleccionaron mediante la prueba de dispersión de gota en el medio mínimo salino de Davis con 1% de glicerol como fuente de carbono y con las tres bacterias que alcanzaron el mayor diámetro en el halo de emulsión se determinó el rendimiento. En el suelo con un HTP de 22 900 mg g-1 se obtuvieron 78 aislados de Pseudomonas spp., entre las que el 84,62% utilizó el petróleo como fuente de carbono y energía en 24-96 horas. El 92,42% de estas bacterias produjo biosurfactante evidenciado por los halos de emulsión de petróleo crudo liviano, con diámetros de 10-30 mm. La concentración de surfactantes producidos por Pseudomonas spp. fue de 1,0-1,5 gL-1, con rendimiento de 35% (Pseudomonas sp. 2HI), 31% (Pseudomonas sp. 8JU) y 19% (Pseudomonas sp. 4CF). Se demostró la producción de surfactantes por Pseudomonas spp. degradadoras petróleo, y su potencial para la remediación de suelos contaminados.
... The culture was incubated for 72 hours with shaking at 200 rpm, 30°C using rotatory incubator shaker Ecotron CH-4103 (INFORS HT, Switzerland). After 72 hours, RL containing supernatant was harvested by centrifuging the culture at 8000 rpm (4°C, 5 min) using HIMAC CR 22N (Hitachi, Japan) (Yin et al., 2009). ...
... Extraction of RL from the supernatant was conducted as described by Yin et al. (2009). The pH of the supernatant was measured using Accumet Basic, AB 15 (Fisher Scientific, Switzerland) and reduced to pH 2 using 6 M HCl. ...
Article
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Biosurfactant rhamnolipid (RL) production using renewable resource is gaining attraction for commercial application. In this study, RL produced from three different strains of Pseudomonas using glycerol as a carbon source was used to evaluate toxicity towards rat skeletal muscle (L6) and liver cancer (HepG2) cells. In the present study, Pseudomonas aeruginosa PAO1 produced the highest concentration of RL (1.53 ± 0.28 g/L) and able to reduce the surface tension (ST) value of water the lowest (29.1 ± 0.5 mN/m). Toxicity evaluation using MTT assay indicated that RL produced does not have a cytotoxic effect towards both cell lines except where 50% inhibition concentration (IC 50) was detected for HepG2 only at high concentration (100 µg/mL) for RL produced by P. aeruginosa PAO1. The RL produced by strains in this study is nontoxic with good ST reducing ability that has potential applications in food, cosmetics and pharmaceutical sector.
... Biosurfactants are amphiphilic molecules containing hydrophilic and hydrophobic moieties [9,[12][13][14][15]. Biosurfactant accumulates at the interface of immiscible fluids and this leads to lowering the interfacial and surface tensions between them and consequently the mobility and solubility of target contaminant would be increased [16,17]. Rather than desorption of PAHs from soil, a supplemental remediation step is required for degradation and mineralization of desorbed contaminants. ...
... The rhamnolipids are formed of one or two rhamnose (hydrophilic) molecules which linked to one or two fatty acids (hydrophobic) and contain saturated or unsaturated alkyl chains [38]. LC-MS/MS analysis showed the presence of seven major congeners (Table 3) and [RhaC 10 C 10 ], respectively [16]. According to these observations and literature, it can be determined that the biosurfactant created by Pseudomonas aeruginosa strain PF2 comprises of a mixture of di-rhamnolipid and mono-rhamnolipid [39,40]. ...
Article
Biological treatment of oily sludge wastes was studied using an isolated halo-tolerant strain Pseudomonas balearica strain Z8. An oily sludge sample was obtained from oil fields of south waste of Iran and was fully characterized. The initial TPH content was 44,500 mg kg−1. The ability of Pseudomonas balearica strain Z8 in production of biosurfactant was investigated using oil displacement method. Results demonstrated that isolated strain is a biosurfactant producing bacteria. The CMC and emulsification index [E24] of produced biosurfactant were 90 mg L−1 and 44% for crude oil. Effect of operational parameters including nitrogen source, sludge/water ratio and temperature were investigated against the time. The most TPH removal of 35% was observed for nitrogen source of NH4Cl, sludge/ water ratio of 1:7 and temperature of 40 °C.
... This method entirely depends on the force needed to lift the ring from the surface of a liquid and the surface tension was measured based on the liquid's surface tension (Accorsini et al., 2012). The principle used to select the best bacteriaproducing biosurfactant was based on decreasing the medium surface tension to below 40 mN/m (Yin et al., 2009a), since the lowering of the surface tension is dependent on the surfactant activities of the isolates (Joy et al., 2017). The average temperature during the experiment was at 26.4 °C. ...
Article
Biosurfactant produced by rhizobacteria has the potential to enhance the degradation of hydrocarbons, leading to more efficient phytoremediation. The aim of this work was to search for bifunctional hydrocarbon-degrading and biosurfactant-producing rhizobacteria. Isolation of bacteria was conducted from three sources (A: rhizosphere of Scirpus grossus planted in garden soils and B: rhizosphere of S. grossus planted in crude oil sludge and C: crude oil sludge) prior to degradation test. Seven isolated rhizobacteria from source B (coded as B1-B7) were screened for a hydrocarbon degradation test with an initial total petroleum hydrocarbon content of 56.13 mg/g. Similar isolated rhizobacteria were also found in source A and C. The best three isolates (B1, B3 and B6) and mixed culture of them, significantly degraded hydrocarbon with 16.2, 8.4, 39.7 and 34.8% removals, respectively. Subsequently, the three pure rhizobacteria and their mixture (B1+B3+B6) were screened for biosurfactant production through tests of oil displacement, drop collapse, emulsification and surface tension. All the pure rhizobacteria and mixed culture had given positive response for all the tests. The presence of biosurfactant produced by rhizobacteria was confirmed by SEM images in which the formation of exopolymers interconnecting individual cells into a complex network of mass was formed due to biosurfactant extraction from bacteria cell. Thus, the three isolated rhizobacteria (B1, B3, and B6), later identified as Bacillus sp. strain SB1, Bacillus sp. strain SB3 and Lysinibacillus sp. strain SB6, respectively, and their mixed culture can simultaneously biodegrade hydrocarbon and produce biosurfactant to enhance the degradation process.
... They are hydrophobic compounds and their water solubility reduces with the incremental number of rings in their molecular structure, which aggravates the low bioavailability of these compounds, making biodegradation of PAHs difficult. Solubility in water of PAHs can be enhanced by addition of biosurfactants as it increases the surface area of hydrophobic water-insoluble compounds contributing in bioremediation of toxic pollutants (Yin et al. 2009). ...
Chapter
Recent decades have shown that there is increase in the considerable interest in research of biogenic surfactants (microbial surfactants, biosurfactants), products of biosynthesis of various microorganisms, as well as the possibilities for their practical use. In the present chapter, the detailed discussion was included regarding sources, isolation, and potential role and applications of biosurfactants as antioxidant agents. This chapter covers the various aspects of biosurfactants such as sources of biosurfactants with examples. It also included the different types of biosurfactants isolated from the microbial sources. It clearly showed the optimum conditions for production of microbial biosurfactants in culture conditions. Microbial-derived surfactants can replace synthetic surfactants in a great variety of industrial applications as detergents, foaming, emulsifiers, solubilizers, and wetting agents. Microbial surfactants or biosurfactants can be defined as a natural class of surface-active compounds produced by microorganisms. Several biosurfactants have strong antibacterial, antifungal, and antiviral activity. In spite of several activities, even microbial biosurfactants have the property of antioxidant activity which is discussed in detail in the present chapter. The chemical structure and properties of various biosurfactants have been extensively discussed and presented in this chapter.
... The FT-IR spectra were recorded on a Perkin-Elmer 31725 X FTIR spectrophotometer in a spectral region of 4000-400cm -1 using Potassium bromide (KBr) solid cells. Spectra were recorded and analyzed using standard method 22,23 . Its data is shown in Figure: 7 (a) and (b). ...
Article
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A novel rhamnolipid producing Acinetobacter boumanii and Acinetobacter variabilis strains were isolated from oil contaminated soil, near refinery area. Biosurfactant compound was separated by solvent extraction of the cell free broth. Semi purified biosurfactant of Acinetobacter boumanii and Acinetobacter variabilis categorized as rhamnolipid using TLC was able to reduce the surface tension of water from 72 to 43 mN/m-1 and 72 to 50 mN/m-1 respectively. Shake flask biosurfactant production studies of Acinetobacter boumanii and Acinetobacter variabilis could produce 1.2g/l and 0.921g/l biosurfactant along with E24 of 44± 0.3 and 40±0.5 at 72 hr. Fourier transform infrared spectroscopy revealed the presence of a highly charged amine, carbonyl, carboxyl and hydroxyl groups. Presence of sixteen rhamnolipid homologues with variation in chain length was revealed from liquid chromatography coupled to mass spectrometry. Further, it elucidated highest relative abundance of Rha-C10:C12 and Rha-C8:2 in both strains, along with unique and major isoform of Rha-Rha-C14: C12 in Acinetobacter variabilis.
... They are hydrophobic compounds and their water solubility reduces with the incremental number of rings in their molecular structure, which aggravates the low bioavailability of these compounds, making biodegradation of PAHs difficult. Solubility in water of PAHs can be enhanced by addition of biosurfactants as it increases the surface area of hydrophobic water-insoluble compounds contributing in bioremediation of toxic pollutants (Yin et al. 2009). ...
... When the rhamnolipid concentration exceeded 50 mg/L, a rapid increase in the solubility of phenanthrene was observed. Similar turning point at a rhamnolipid concentration of 50 mg/L was reported previously [42]. ...
Article
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Rhamnolipids are extensively studied biosurfactants due to their potential in many industrial applications, eco-friendly production and properties. However, their availability for broader application is severely limited by their production costs, therefore the optimization of efficacy of their cultivation gains significance as well as the information regarding the physio-chemical properties of rhamnolipids resulting from various cultivation strategies. In this work, the bioprocess design focused on optimization of the rhamnolipid yield of Pseudomonas aeruginosa DBM 3774 utilizing the response surface methodology (RSM). Six carbon sources were investigated for their effect on the rhamnolipid production. The RSM prediction improved the total rhamnolipid yield from 2.2 to 13.5 g/L and the rhamnolipid productivity from 11.6 to 45.3 mg/L/h. A significant effect of the carbon source type, concentration and the C/N ratio on the composition of the rhamnolipid congeners has been demonstrated for cultivation of P. aeruginosa DBM 3774 in batch cultivation. Especially, changes in presence of saturated fatty acid in the rhamnolipid congeners, ranging from 18.8% of unsaturated fatty acids (carbon source glycerol; 40 g/L) to 0% (sodium citrate 20 g/L) were observed. This demonstrates possibilities of model based systems as basis in cultivation of industrially important compounds like biosurfactants rhamnolipids and the importance of detailed study of interconnection between cultivation conditions and rhamnolipid mixture composition and properties.
... Response surface methodology (RSM) was extensively used statistical technique for media optimization and for designing experiments, evaluating the effects of factor and relative significance and searching the optimum factors related to desired response. It has the intense ability to interpret the interactive effects among input variables are some attractive features of RSM [2,11,12,[16][17][18][19][20][21][22][23][24][25][26][27][28]. ...
... The prediction will use the descriptors of both, the biosurfactant, and the solubilizate, but also the conditions of the measurement, which to our knowledge, is a first such attempt. The data used for this come from literature [1,4,27,33,[53][54][55][56][57][58][59][60][61][62][63][64][65][66][67][68] as well as experiments. ...
Article
Full-text available
The efficiency of micellar solubilization is dictated inter alia by the properties of the solubilizate, the type of surfactant, and environmental conditions of the process. We, therefore, hypothesized that using the descriptors of the aforementioned features we can predict the solubilization efficiency, expressed as molar solubilization ratio (MSR). In other words, we aimed at creating a model to find the optimal surfactant and environmental conditions in order to solubilize the substance of interest (oil, drug, etc.). We focused specifically on the solubilization in biosurfactant solutions. We collected data from literature covering the last 38 years and supplemented them with our experimental data for different biosurfactant preparations. Evolutionary algorithm (EA) and kernel support vector machines (KSVM) were used to create predictive relationships. The descriptors of biosurfactant (logPBS, measure of purity), solubilizate (logPsol, molecular volume), and descriptors of conditions of the measurement (T and pH) were used for modelling. We have shown that the MSR can be successfully predicted using EAs, with a mean R2 val of 0.773 ± 0.052. The parameters influencing the solubilization efficiency were ranked upon their significance. This represents the first attempt in literature to predict the MSR with the MSR calculator delivered as a result of our research.
... The crude biosurfactant was spotted on two TLC plates (Merck, India) along with the solvent extract purified biosurfactant. They were separated using the solvent chloroform: water: methanol in ratio 65: 24: 4 15 . Ninhydrin reagent and Anthrone reagent was sprayed on the two chromatograms respectively. ...
Article
Full-text available
Biosurfactants are surface active compounds, which may be of microbial, animal or plant origin. They are typically less toxic and less persistent than the synthetically derived surfactants. The current study intended to analyze the biosurfactants production and its antagonistic activity against Candida albicans biofilm formation. Isolation of biosurfactant producing organism was carried out using swab sample of human vagina and from oil contaminated soil samples. Isolates were screened for biosurfactant production by using oil spread assay and the organisms showing higher activity were selected. The Emulsification assay was done and the E24 was found to be 20.83% for cell free extract of growth medium of isolate B1.The selected isolates were further studied for yield of biosurfactant produced by cultivation in MRS broth and extraction by chloroform and methanol (3:1) extraction. The yield of biosurfactant for isolate B1was found to be4.55gl-1.Theextracted biosurfactant was separated by TLC and identified to be a lipopeptide by FTIR spectroscopy. The isolate with maximum yield of biosurfactant was identified as Lactobacillus fermentum using VITEK II Compact System for microbial identification system. The percentage biofilm inhibition activity of the biosurfactant was studied by CFU assay followed by adhesion assay and by pre-coating experiment. On the basis of above studies, it concludes that use of biosurfactant producing organism can be effective weapon against colonizing opportunistic C. albicans and can be applied in medical devices for inhibition of biofilms formation. Microbial adhesion also decreased from 85% to 11% with78.125 to 2500 µg/ml of biosurfactant. The lipopeptide extracted from isolated isolate B1 also showed powerful penetration capacity in the biofilm and killed 91% C. albicans as seen by CFU assay and a highest inhibition at 2500µg/ml and 1250µg/ml concentration as studied by pre-coating experiment.
... Based on the molecular weight, they are divided into low-molecular-mass and high-molecular-mass biosurfactants [24][25][26]. The major classes of biosurfactants are glycolipids, phospholipids, polymeric biosurfactants, and lipopeptides (surfactin) [7,[27][28][29]. Major biosurfactants, their classes, and the microorganisms involved are presented in Table 1. ...
Chapter
Biosurfactants are gaining more research interest because of their rare benefits. Its application within the food industry has proven that it can sustainably replace the utilization of synthetic surfactant in food production processes and products. This chapter includes merits and demerits of biosurfactants, classification of biosurfactants, and comparison between biosurfactants and synthetic surfactants. A detailed review on the utilization of biosurfactants in the food industry as an emulsifier, preservatives, antioxidant, heavy metal removal, etc., was also captured. Therefore, biosurfactant plays a key role in the food production process.
... Effect of Environmental factors on biosurfactant production: The effect of different environmental factors like pH (5)(6)(7)(8)(9)(10), temperature (10 0 -50 0 ) and salt concentration (1% -5%) Current Updates In Life Sciences 615 on biosurfactant production was determined by selecting the different range of pH, temperature and salt concentration one by one and keeping other factors constant. (Yin et al., 2009). ...
Chapter
Full-text available
The present study has focused on the isolation of airborne fungal spores from indoor environment of laboratories of Government Institute of Forensic Science, Nagpur by the Petri plate exposure culture plate method helped us in determining the occurrence of fungal species. The species found were Aspergillus, Penicillium, Curvularia, Fusarium, Cladosporium, Rhizopus, Aspergillus niger, and some unidentified species. Mycological evidence could be used in the investigation of both criminal and civil cases.
... Optimizing fermentation conditions and augmenting biosurfactant yield could contribute to expand the biosurfactant applications. A variety of factors including medium nutrition (carbon, nitrogen source and salinity) (He et al., 2016;Lee et al., 2016;Sakthipriya et al., 2015) and fermentation conditions (pH, temperature, agitation speed, inoculum concentration) could affect biosurfactant production (Yin et al., 2009;Jiang et al., 2020;Ibrahim et al., 2013). ...
Article
The present study was conducted to enhance the biosurfactant production yield of Pseudomonas sp. CQ2 isolated from the Chongqing oilfield (China). Besides, the capability of biosurfactant and underlying mechanism for re-mediation of heavy metal contaminated soil was also investigated. Our results suggested that maximum biosur-factant production (40.7 g/L) was attained at 35°C by using soybean oil and ammonium nitrate as carbon and nitrogen sources with pH 7, rotational speed of 175 rpm and inoculation ratio of 3%). The removal efficiencies of 78.7, 65.7 and 56.9% for Cd, Cu and Pb respectively were achieved at optimized bioleaching conditions (pH: 11, soil/solution ratio: 30:1 and non-sterilized soil), comparative tests between common chemical surfactants (SDS, Tween-80) and biosurfactants demonstrated the larger removal capacity of biosurfactants. Through SEM-EDX, it was found that the granular material disappeared, the content of Cd, Cu and Pb decreased significantly, and the soil surface became smooth with hole formation after soil washing following bioleaching. ATR-FTIR results showed that the carboxyl functional groups in biosurfactants could chelate heavy metals. These results indicated that biosurfactants from Pseudomonas sp. CQ2 could effectively eliminate Cd, Cu, and Pb from soil.
... Meanwhile, Techaoei et al., (2011) documented that the effects of lower biosurfactant activity in acidic condition to be due to its negatively charged molecules. Similar results had been reported for biosurfactant production from other microorganisms such as P. aeruginosa which was stable at a wide range of pH and sodium chloride concentrations (Yin et al., 2009;Vijayakumar and Saravanan, 2011;Techaoei et al., 2011;Khopade et al., 2012). ...
Article
Biosurfactants are one of the microbial bioproducts that are naturally synthesized and are applicable for many industrial purposes. In this study, antibacterial, stability and antibiotic susceptibility of biosurfactant was evaluated. Biosurfactants produced from different substrates (groundnut cake, cassava flour waste, pome, cooking oil, engine oil, cassava waste water, molasses, cassava peel, potato) by Pseudomonas taenensis were evaluated for antibacterial activity using agar well diffusion method. Antibiotics susceptibility of Pseudomonas taenensis was carried out using different antibiotics (augmentin, ofloxacin, tetracyclin and ciprofloxacin, cotrimoxazole, pefloxacin, amoxylin, ceftriazone, nitrofuranton and gentamycin). The stability of the biosurfactant was evaluated by adjusting the biosurfactant to: pH (2, 4, 6, 8, 10 and 12) using 1M NaOH and 1M HCl, temperature (4, 30, 37, 55, 75 and 100 °C) and NaCl (0, 5, 10, 15, 20 and 25 %). Results showed that only biosurfactant produced using cassava waste water as substrate was sensitive to Escherichia coli while biosurfactant produced using cassava flour waste, pome and molasses were sensitive to Staphylococcus aureus. Biosurfactant-producing isolate (Pseudomonas taenensis) was sensitive to four antibiotics (augmentin, ofloxacin, tetracyclin and ciprofloxacin) and resistant to six antibiotics (cotrimoxazole, pefloxacin, amoxylin, ceftriazone, nitrofuranton and gentamycin). Biosurfactant was stable over all the wide ranges of pH, temperature and sodium chloride concentrations investigated. This study therefore revealed that biosurfactant have good stability, thus, could survive environmental stress; Not all biosurfactant and biosurfactant producers have antimicrobial and antibiotic property.
... They are hydrophobic compounds and their water solubility reduces with the incremental number of rings in their molecular structure, which aggravates the low bioavailability of these compounds, making biodegradation of PAHs difficult. Solubility in water of PAHs can be enhanced by addition of biosurfactants as it increases the surface area of hydrophobic water-insoluble compounds contributing in bioremediation of toxic pollutants (Yin et al. 2009). ...
Chapter
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Petroleum industries are considered as major energy resources, but as simultaneously producing large amounts of hydrocarbon wastes that are discharged into soil and water bodies. Environmental pollution due to exponential development of the petrochemical industries was a major concern in the twentieth century. Oil and oil products contamination, which belong to the carcinogenic and neurotoxic organic pollutants family, pose a severe threat to general health of public, choke aquatic life to death, and accumulate in soil and disturb the ecosystem. Numerous different technologies have been used for the removal of hydrocarbon/oil pollutants from polluted sites, such as physical, chemical, and biological methods. Conventional physical and chemical methods can only immobilize at site or transfer’s contaminants from one medium to another and can even result in production of toxic by-products. Hence, petroleum oil and petroleum hydrocarbons cannot be entirely eradicated with physical and chemical methods. Thus, focus is being given to biological methods generally. Biosurfactants are considered as a promising alternative for the removal of oil pollutants due to their amphiphilic nature: they have the capability to reduce interfacial tension, disperse oil particles, high surface activity, lower toxicity, biodegradability and environmental friendliness, and are active under extreme conditions of salinity, pH and temperature. This chapter briefly discusses how microorganisms produce biosurfactant when they feed on insoluble substrates such as oil/petroleum waste. It also reveals the biosurfactant mode of action to remove petroleum waste and its derivatives (heavy metals, PAHs, etc.) from oil spills, cleaning pipelines, and containers. Biosurfactants emerge as potential biomolecules in petroleum industry waste bioremediation and need to be scaled up for the upcoming years.
... Thus, molecular ions produced as positiveion and negative-ion through a specific pattern of fragmentation. The LCMS analysis and extraction of RL conducted by referring method fromAbdel- Mawgoud et al. (2014) andYin et al. (2009) with some modifications. ...
Thesis
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Rhamnolipid (RL) is a glycolipid biosurfactant produced by bacterial fermentation. Owing its completely biodegradability and non-toxic attributes, RL applied in production of fine chemicals, enhancement of biodegradation, food industries and pharmaceutical products. Nevertheless, commercialization of RL is still a challenge due to the bottleneck in economics of production. In this study, RL produced using a marine P. aeruginosa UMTKB-5 strain from renewable carbon feedstock, which includes agro-industrial by-products. The production in shake-flask was investigated in detail using statistical analysis to determine interaction between variables in culture parameters. Besides, the agro-industrial by-products namely cane molasses and sweet water were characterized for their components. The concentration of RL produced was measured spectrometrically using orcinol assay. The surface tension was measured using “Du Nouy Ring” method. The Liquid Chromatography Electronspray Ionization Mass Spectrometry (LC-ESI-MS) used to characterize different RL congeners. Preliminary trial of RL production by this strain was carried out in a bioreactor. RL production was the highest at 3.12 g/L when combinations of fructose (C/N 50) with NH2CONH2 or NH4NO3 were applied. Approximately 2.17 ± 0.38 g/L and 1.67 ± 0.75 g/L with glucose and glycerol when NH2CONH2 supplemented as nitrogen source. RL produced in the range of 0.08 – 0.44 g/L and 0.19 – 0.22 g/L with molasses and sweet water, respectively. The Tukey’s test conducted showed significantly different with p < 0.0007. The effective surface tension (ST) activities in the range of 25.9 – 27.4 mN/m were obtained with fructose-NH2CONH2 (C/N 50) and fructose-NH4NO3 (C/N 50). LC-ESI-MS analysis identified the presence of di-RL congeners of RhaRhaC10C12:1, RhaRhaC10C12/ RhaRhaC12C10, RhaRhaC10 and RhaRhaC10C10 in RL produced from combinations of fructose and NH4NO3 as well as glucose and NH2CONH2. Meanwhile, P. aeruginosa UMTKB-5 strain produced mono-RL types (RhaC10, RhaC8C10/RhaC10C8, RhaC10C12 /RhaC12C10) in the presence of glycerol and NH2CONH2. The findings of this study highlights the potential application of the marine P. aeruginosa UMTKB-5 strain for RL production from different carbon sources, which includes agro-industrial by-products. The types of RL congeners produced can be customized by varying the carbon and nitrogen sources. The ST properties of the RL obtained suggest that it can be used for reduction of interfacial tension between two immiscible liquids.
... These results were supported by Saikia et al. (2011) and Anyanwu (2010) where they showed rhamnolipid produced by P. aeruginosa as thermostable even at an autoclaving temperature. Yin et al. (2009) andTechaoei et al. (2011) reported rhamnolipid activity remained stable at neutral and basic pH due to the structural nature of rhamnolipid. In similar studies by Lan et al. (2015), rhamnolipid activity remained relatively stable at NaCl concentration up to 8% then the change in rhamnolipid activity occurred with rising NaCl concentration. ...
Article
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A wide variety of biosurfactant-producing microorganisms were isolated from hydrocarbon-contaminated soil and were screened for biosurfactant production using conventional methods including oil spreading test, emulsification index, emulsification activity and CTAB agar test. Among the isolated bacteria, A2 isolate, a Gram negative bacterium was selected for further studies based on its highest activity and was identified by 16S rDNA sequencing as Pseudomonas aeruginosa. The presence of specific genes responsible for the biosynthesis of mono-rhamnolipid (rhlB) and dirhamnolipid (rhlC) were detected. Optimization of different cultural conditions (carbon source, carbon concentration, nitrogen source, nitrogen concentration, pH, incubation time, and inoculum concentration) were performed to achieve maximum production of biosurfactant. Production of biosurfactant was estimated in terms of oil spreading test, emulsification index, emulsification activity and biomass as 15 cm, 60 %, 1.831 ± 0.025 and 2.851 ± 0.043 g/l respectively. The obtained results demonstrated that the maximum rhamnolipid production (5.42 ± 0.475 g/l) happened using olive oil at a concentration of 2% as carbon source, 2 g/l of urea as nitrogen source, inoculum size of 3 %, pH: 7, and 6 days incubation period at 30°C. The analysis of the extracted biosurfactant by TLC, FTIR spectra and GC-MS analysis confirmed that the biosurfactant nature was rhamnolipid. The rhamnolipid could decrease the surface tension of water to 28.49 mN/m and exhibited good stabilities at high temperatures (up to autoclaving at 121°C), salinities (up to 10 % NaCl), and pH values (up to pH: 10 except 4 and 2 pH).
... Jimoh and Lin (2019b) investigated that electrospray ionization coupled with liquid chromatography helps to identify the biomolecule with low concentration and secondary metabolites as in the biosurfactant compound. For instance, Yin et al. (2009) also used electrospray ionization coupled with liquid chromatography to identify the chemicals constituents from biosurfactants produced from Paenibacillus dendritiformis CN5. They identify eight amino acid constituents from biosurfactant biomolecule produced from P. aeruginosa S6, including four crucial amino acids, such as RhaC12:1C10, RhaC8C10, RhaRhaC10C12:1, and RhaC10C10. ...
Article
Due to the increased use of crude oil and other oil-related products, a large amount of waste is produced and discharged into the environment. These wastes contain toxic heavy metals and petroleum hydrocarbon and lead to further deterioration of the terrestrial and aquatic ecosystems. Their increasing amounts and residual leachates are considered the main obstacle to restoring contaminated environments. Biosurfactants are compounds having high emulsification properties, wetting performance, de-emulsification, detergent formulation, foam formation, and surface activity enhancement to minimize the interfacial tension between liquids, a liquid and a gas or a liquid and a solid. Such features make biosurfactants of high potential applications in diverse industrial set-ups. This field attracts attention from scientists (and policymakers) to develop novel, cost-effective and renewable biosurfactants using molecular engineering and emerging downstream processing. This review comprehensively discusses recent applications of biosurfactants, their preparation, characterization, and potential environmental and other industrial applications. The recent advances in biosurfactants using recombinant DNA technology, mutants and hyper-active microbes were also reviewed. We highlighted the use of sophisticated and highlyaccurate characterization techniques such as high performance-liquid chromatography (HPLC), nuclear magnetic resonance (NMR), thin-layer chromatography (TLC), and gas chromatography-mass spectrometry (GC-MS). Strategies to enhance the efficiency and biosurfactants productivity at a large scale is also discussed.
... Biosurfactants are generally classified based on two things: molecular weight and chemical composition. Some of the important classes of biosurfactants include polymeric biosurfactants, glycolipids, phospholipids, and lipopeptides (surfactin) (Yin et al., 2009;Makkar and Rockne, 2003). Biosurfactants are characterized by ecofriendliness, biodegradability, low toxicity, and better surface and interfacial activity, making them a suitable alternative to synthetic surfactants (Banat et al., 2014;Cameotra and Makkar, 2010;Mnif and Ghribi, 2015). ...
Book
Mangrove ecosystems are noteworthy intertidal estuarine wetlands having the two unique components of terrestrial and marine ecosystems along the coastlines. This ecosystem is a carbon sink due to the formation of an estuarine environment between freshwater and tidal water discharges. The ecosystem is abundant with biologically diverse plants, animals, and microbial species. Microflora found in the ecosystem, along with their biotic and abiotic components and their interactions, play an important role in maintaining the rhizosphere. They contribute diverse valuable products of biotechnological importance. The high primary productivity, abundant detritus, rich organic carbon, and reduced pollution of mangrove ecosystems are due to the contributions by the mangrove’s microbes. These microbes also significantly contribute in depositing hydrocarbons, recycling nutrients, consuming gases that affect global warming, destroying pollutants, treating anthropogenic waste, bioremediation, carbon fixation, and biosurfactants. Microflora of the mangrove environment are used in producing drugs, enzymes, vaccines, antimicrobial agents, immune modulators, anticancer treatments, insecticides, and vitamins. Yet even though the mangrove ecosystem consists of large numbers of microbes, very little description is found in way of phylogenetic analysis of mangrove microbes. Biotechnology and bioinformatics intervention can give rise to many viable products of great importance from the microbial diversity of the ecosystem. The present chapter is focused on the potential applications of microbes found in the mangrove ecosystem, specifically in biosurfactant, bioremediation, enzymatic, antimicrobial, and agricultural activities.
... Biosurfactants are generally classified based on two things: molecular weight and chemical composition. Some of the important classes of biosurfactants include polymeric biosurfactants, glycolipids, phospholipids, and lipopeptides (surfactin) (Yin et al., 2009;Makkar and Rockne, 2003). Biosurfactants are characterized by ecofriendliness, biodegradability, low toxicity, and better surface and interfacial activity, making them a suitable alternative to synthetic surfactants (Banat et al., 2014;Cameotra and Makkar, 2010;Mnif and Ghribi, 2015). ...
Chapter
This study deals with the assessment of mangrove floral diversity at three major districts of Odisha: Kendrapara, Jagatsinghpur, and Bhadrak, which constitute major parts of state mangrove vegetation. In these three districts, the study sites included Mahanadi mangrove wetland (MMW) of Kendrapara, the river mouth regions of the river Devi (DRM) and Baitarani (BRM) in Jagatsinghpur and Bhadrak district, respectively, and the Baitarani river bank (BRB) region of Bhadrak district. The total area of study included 1 ha in MMW, 0.5 ha in DRM, and 0.1 ha each in BRM and BRB. A total of 63 species of plant were found to be distributed within the study sites that included 27 trees, 13 herbs, 17 shrubs, 5 climbers, and 1 creeper. Among trees, Avicennia marina came out as the dominant species for BRM (important value index-IVI=70.33) and MMW (IVI=117.308), while Avicennia alba was dominant in DRM (IVI=108.33), and Sonneratia caseolaris was dominant in BRB (IVI=137.40). The highest diversity was found at MMW (Shannon diversity index=0.79±0.38 and Simpson’s index=0.42±0.22), and the least diversity was found at BRB (Shannon diversity index=0.76±0.08 and Simpson’s index=1.19±0.15), but the evenness was highest in BRB (0.63±0.06) followed by MMW (0.48±0.15) and lowest in DRM (0.38±0.13). The soil parameters of the study sites showed variations with a mean pH ranging from 5.1 in BRM to 7.12 BRB, electrical conductivity from 0.01 to 0.05 S/m and organic carbon from 0.51% in BRB to 1.97% in DRM. This study will act as supplement information for mangrove vegetation of Odisha, which may be implemented further for the conservation and management of mangroves on the east coast of India.
... Biosurfactants are generally classified based on two things: molecular weight and chemical composition. Some of the important classes of biosurfactants include polymeric biosurfactants, glycolipids, phospholipids, and lipopeptides (surfactin) (Yin et al., 2009;Makkar and Rockne, 2003). Biosurfactants are characterized by ecofriendliness, biodegradability, low toxicity, and better surface and interfacial activity, making them a suitable alternative to synthetic surfactants (Banat et al., 2014;Cameotra and Makkar, 2010;Mnif and Ghribi, 2015). ...
Chapter
Mangrove ecosystems are noteworthy intertidal estuarine wetlands having the two unique components of terrestrial and marine ecosystems along the coastlines. This ecosystem is a carbon sink due to the formation of an estuarine environment between freshwater and tidal water discharges. The ecosystem is abundant with biologically diverse plants, animals, and microbial species. Microflora found in the ecosystem, along with their biotic and abiotic components and their interactions, play an important role in maintaining the rhizosphere. They contribute diverse valuable products of biotechnological importance. The high primary productivity, abundant detritus, rich organic carbon, and reduced pollution of mangrove ecosystems are due to the contributions by the mangrove’s microbes. These microbes also significantly contribute in depositing hydrocarbons, recycling nutrients, consuming gases that affect global warming, destroying pollutants, treating anthropogenic waste, bioremediation, carbon fixation, and biosurfactants. Microflora of the mangrove environment are used in producing drugs, enzymes, vaccines, antimicrobial agents, immune modulators, anticancer treatments, insecticides, and vitamins. Yet even though the mangrove ecosystem consists of large numbers of microbes, very little description is found in way of phylogenetic analysis of mangrove microbes. Biotechnology and bioinformatics intervention can give rise to many viable products of great importance from the microbial diversity of the ecosystem. The present chapter is focused on the potential applications of microbes found in mangrove ecosystem, specifically in biosurfactant, bioremediation, enzymatic, antimicrobial, and agricultural activities.
... The production and accumulation of biosurfactant during exponential growth phase and stationary phases has already been reported from different microorganism e.g. Bacillus subtilis (Nitschke and Pastore, 2006;Ghojavand et al., 2008), Pseudomonas aeruginosa (Yin et al., 2009; and Bacillus licheniformis (Suthar and Nerurkar, 2016;Liu et al., 2016). Work have also been conducted with several lactobacillus strains but the biosurfactant yield was significantly lowered as compared to this work (Sharma and Saharan, 2016;Ciandrini et al., 2016;Morais et al., 2017). ...
... On comparison of the LC-MS data of other reports, total seven numbers of mono-and di-rhamnolipids congeners (Table 2) were identified in the rhamnolipid produced by Pseudomonas sp. TMB2 based on the m/z ratio (Yin et al. 2009;Patowary et al. 2017;Chen et al. 2018). Predominant peaks were observed at m/z 302. ...
Article
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The present study describes the ex-situ production of a biosurfactant by Pseudomonas sp. TMB2 for its potential application in enhancing oil recovery. The physicochemical parameters such as temperature and pH were optimized as 30 °C and 7.2, respectively, for their maximum laboratory scale production in mineral salt medium containing glucose and sodium nitrate as best carbon and nitrogen sources. The surface activity of the resulting culture broth was declined from 71.9 to 33.4 mN/m having the highest emulsification activity against kerosene oil. The extracted biosurfactant was characterized chemically as glycolipid by Fourier-transform infrared spectroscopy and ¹H and ¹³C nuclear magnetic resonance spectroscopy analyses. The presence of mono-rhamnolipids (Rha-C8:2, Rha-C10, Rha-C10-C10, and Rha-C10-C12:1) and di-rhamnolipids (Rha-Rha-C12-C10, Rha-Rha-C10-C10, and Rha-Rha-C10-C12:1) congeners were determined by liquid chromatography-mass spectroscopy analysis. The thermostability and degradation pattern of the candidate biosurfactant were tested by thermogravimetry assay and differential scanning calorimetry studies for its suitability in ex-situ oil recovery technology. The rhamnolipid based slug, prepared in 4000 ppm brine solution reduced the interfacial tension between liquid paraffin oil and aqueous solution to 0.8 mN/m from 39.1 mN/m at critical micelle concentration of 120 mg/L. The flooding test was performed using conventional core plugs belonging to oil producing horizons of Upper Assam Basin and recovered 16.7% of original oil in place after secondary brine flooding with microscopic displacement efficiency of 27.11%.
... Surfactants are active chemicals in soaps and detergents that can concentrate at the air-water interface. They are frequently employed to remove oily materials from a particular medium due to their propensity to concentrate at the air-water interface which comes from their ability to enhance the aqueous solubility of Non-Aqueous Phase Liquids (NAPLS), by lowering the surface/interfacial tension at air-water and water-oil interfaces (Yin et al, 2009). Surfactants are one of the primary ingredients of household detergent of all types, home cleaning products including floor cleaner and toilet cleaner, and personal use products like shampoos, shower gels and hand soaps. ...
Article
Surfactants are extensively employed in industrial, agricultural, and food, cosmetics and pharmaceuticals applications. Chemically produced surfactants cause environmental and toxicological hazards. Recently, considerable research has led to environmentally friendly procedures for the synthesis of several forms of biosurfactants from microorganisms. In comparison to chemical surfactants, biosurfactants have several advantages, such as biodegradability, low toxicity and ease of availability of raw materials. This paper offers an in-depth review of the types of surfactants, the need for bio-surfactants, their types and advantages, especially biodegradability. It also examines the biodegradability of selected four surfactants and finds that the biosurfactant is more easily biodegradable than the chemical surfactants.
... Biosurfactant groups include glycopeptides, fatty acids, glycolipids, phospholipids, lipopolysaccharides, and glycol-glycerolipids . Rhamnolipids, trehalolipids, and sophorolipids are well-known glycolipids (Makkar & Rockne, 2003;Yin, Qiang, Jia, Ye, & Peng, 2009). The biosurfactants are used extensively in industrial, agriculture, food, cosmetics, and pharmaceutical applications because of its straight-out properties includes low toxicity, surface and interface activity (the surface tension of water/ air interface reduced by the amphiphilic molecules), availability, biodegradability, penetrating ability, act as antimicrobial agent, microbial growth enhancement, wetting agent, and emulsifying agent . ...
Chapter
The biosurfactants produced by the microbes are mostly glycolipid which owing to their low toxicity, biodegradability shows a greater utility than the chemical surfactants. With the enhanced use of biosurfactants the envi�ronment gets converted into a green environment. They apart from hav�ing these properties have the emulsifying capability, pore-forming ability and antibiofilm forming abilities which have made them potent biopesticides. Numerous reviews showed the efficiency of glycolipids. The antiphyto�pathogenic activities of glycolipids, the insecticidal and larvicidal activities their antiadhesive properties have attracted the industries in producing amplified amounts of these green compounds
... After phase separation, the collected organic phase was treated with anhydrous sodium sulfate to remove water and then concentrated on a rotary evaporator at 40 °C to obtain crude biosurfactant extract. The level of biosurfactant production by lactic acid bacteria was evaluated by measuring this biosurfactant extract in g/L [22]. ...
... Biosurfactant groups include glycopeptides, fatty acids, glycolipids, phospholipids, lipopolysaccharides, and glycol-glycerolipids . Rhamnolipids, trehalolipids, and sophorolipids are well-known glycolipids (Makkar & Rockne, 2003;Yin, Qiang, Jia, Ye, & Peng, 2009). The biosurfactants are used extensively in industrial, agriculture, food, cosmetics, and pharmaceutical applications because of its straight-out properties includes low toxicity, surface and interface activity (the surface tension of water/ air interface reduced by the amphiphilic molecules), availability, biodegradability, penetrating ability, act as antimicrobial agent, microbial growth enhancement, wetting agent, and emulsifying agent . ...
Chapter
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Biosurfactants may be defined as molecules of amphiphilic nature having the capacity of decreasing both surface as well as interface tension between nonmiscible fluids. These are generally classified on the basis of their microbial origin and chemical composition. These are environment friendly molecules with lesser toxic effect and having higher biodegradation. These have full potential of replacing the chemical surfactants. The most important biosurfactants include Glycolipids and lipopeptides. Some other classes of biosurfactants are Phospholipids, fatty acids and Polymeric. These biosurfactants are manufactured throughout the microbial growth on both water soluble or insoluble substrates. These have widespread usage in bioremediation, pathogens management, medicines, cosmetics, and petroleum industry. Although, their usage is encouraging in bioremediation practices, their mass production on industrial basis is a tough task because of costly inputs low manufacturing outputs.
... They are hydrophobic compounds and their water solubility reduces with the incremental number of rings in their molecular structure, which aggravates the low bioavailability of these compounds, making biodegradation of PAHs difficult. Solubility in water of PAHs can be enhanced by addition of biosurfactants as it increases the surface area of hydrophobic water-insoluble compounds contributing in bioremediation of toxic pollutants (Yin et al. 2009). ...
Chapter
Surfactants derived from microbes belong to the diverse group of surface-active metabolites which are secreted during their growth on hydrophobic substrates. The use of chemical surfactants as a detergent in different industries such as leather, petroleum, paper, dairy, cosmeceuticals, and pharmaceuticals is limited due to their hazardous effects on the aqueous and territorial ecosystem. This found the basis for the use of biosurfactants as a detergent for industrial and household applications. In recent years, the use of biosurfactants in the cleaning of storage tanks in petroleum industries, cleaning of membranes during ultrafiltration, and remediation of leather dust from the leather industry is increased. Different companies are manufacturing biosurfactant-based dish-washing agents. Some patents are also claiming the role of biosurfactants in hair and skin cosmetics. This chapter describes the chemical nature of biosurfactants, media composition required for microbial growth, genetic regulation and biosynthesis of surfactants, and the application of biosurfactants in different fields as cleansing agents.
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Biosurfactant-producing bacteria can be found in contaminated environments such as biopurification systems (BPS) for pesticide treatments. A total of 18 isolates were screened to determine their ability to produce extracellular biosurfactants, using olive oil as the main carbon source. Out of the eighteen isolates, two strains (C11 and C27) were selected for biosurfactant production. The emulsification activities of the C11 and C27 strains using sunflower oil was 58.4 and 53.7%, respectively, and 46.6 and 48.0% using olive oil. Using molecular techniques and MALDI-TOF, the strains were identified as Bacillus amyloliquefaciens (C11) and Streptomyces lavendulae (C27). The submerged cultivation of the two selected strains was carried out in a 1 L stirred-tank bioreactor. The maximum biosurfactant production, indicated by the lowest surface tension measurement, was similar (46 and 45 mN/m) for both strains, independent of the fact that the biomass of the B. amyloliquefaciens C11 strain was 50% lower than the biomass of the S. lavendulae C27 strain. The partially purified biosurfactants produced by B. amyloliquefaciens C11 and S. lavendulae C27 were characterized as a lipopeptide and a glycolipid, respectively. These outcomes highlight the potential of the selected biosurfactant-producing microorganisms for improving pesticides’ bioavailability and therefore the degradational efficacy of BPS.
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Rhamnolipid (RL) biosurfactant which is produced by Pseudomonas species is one of the most effective surface-active agents investigated in the literature. Over the years, many efforts have been made and an array of techniques has been developed for the isolation of RL produced strains as well as RL homolog characterization. Reports show that RL productivity by the best-known producer, Pseudomonas aeruginosa, is very diverse, from less than 1 gr/l to more than 200 g L�1. There are some major parameters that can affect RL productivity. These are culture conditions, medium composition, the mode of operation (batch, fed-batch and continuous), bioengineering/gene manipulation and finally extraction methods. The present paper seeks to provide a comprehensive overview on the production of rhamnolipid biosurfactant by different species of Pseudomonas bacteria. In addition, we have extensively reviewed their potential for possible future applications.
Chapter
As a result of global industrialization and increasing population there has been an alarming increase in the global demands for energy which is being fulfilled by exploiting various natural resources significantly hydrocarbons. As a result enormous amounts of hydrocarbons and hydrocarbon­based products have been released into the environment, threatening health and sustainability of the ecosystem. These different types of hydrocarbon­contaminated environments vary in their microbial composition and serve as an excellent reservoir of microbial flora, with a potential to degrade hydrocarbons and produce biosurfactants. In this chapter, an overview of biosurfactant­ producing microorganisms from hydrocarbon­contaminated environments and their role in utilisation and degradation of hydrocarbon compounds is presented. Microorganisms growing in hydrocarbon ­rich environments undergo many adaptations, such as production of biosurfactants, which increases access to these hydrophobic substrates. Industrially, biosurfactants, which constitute as a group of surface­active amphiphilic compounds, are of great significance as they are biodegradable and nontoxic compared to synthetic chemical surfactants. Thus, biosurfactants have found wide applications and are used in bioremediation, oil exploration and enhanced recovery, health care, oil and food processing industries.
Article
This article presents a study of the interfacial properties of oil-in-water emulsions containing sugar esters and polysaccharides. Sucrose fatty acid esters were synthesized using immobilized Candida antarctica lipase B. A yield of 53.4% was obtained using 2-methyl-2-butanol and 1:3 molar ratio of sucrose:stearic acid. Equilibrium surface tension was 45 mN/m and low critical micellar concentration (CMC) value was obtained (ca. 10 mg/mL), characteristic of non-ionic surfactant. The interfacial properties of mixtures of sucrose esters and polysaccharides, at the oil-water interface were determined using a pendant drop tensiometer. Addition of polysaccharides increased the interfacial tension. Studies of interfacial viscoelasticity showed that the films were predominantly elastic. The presence of polysaccharides in emulsions resulted in flocculated droplets. All the emulsions presented great stability along 28 days with no creaming formation.
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Resumen Los biosurfactantes (BS) son un grupo de moléculas de origen microbiano que se caracterizan por ser anfipáticas, es decir que sus moléculas presentan dos partes diferentes, una hidrofóbica y otra hidrofílica. Son un grupo estructuralmente diverso de moléculas tensoactivas, que presentan en general menor toxicidad y mayor biodegradabilidad que los surfactantes sintéticos. Entre las aplicaciones más estudiadas de los BS están aquellas relacionadas con la industria del petróleo y la bioremediación de sitios o residuos contaminados con hidrocarburos. No obstante, los biosurfactantes pueden ser utilizados para otro tipo de compuestos xenobióticos, como es el caso de los plaguicidas. Estos compuestos permiten controlar la proliferación de plagas y enfermedades de los cultivos y del ganado, así como reducir o evitar las pérdidas en la producción de alimentos y contribuir al control de los vectores de diversas enfermedades. No obstante la importancia económica de los plaguicidas, es necesario destacar que su aplicación indiscriminada y sin control ha generado diversos problemas como intoxicación a seres humanos, efectos carcinogénicos, teratogénicos y mutagénicos, además de numerosos problemas ambientales como contaminación de mantos freáticos, aguas continentales y costeras; contaminación del suelo y bioacumulación en las cadenas alimentarias. Generalmente los plaguicidas son de naturaleza hidrofóbica, por lo que el uso de los BS puede ser prometedor en la remediación de sitios contaminados o en el tratamiento biotecnológico de residuos de plaguicidas.
Chapter
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Microbial exopolysaccharides (EPS), a carbohydrate biopolymer containing several distinct monosaccharides and non-carbohydrate substituents (molecular mass from 10 to 1000 kDa), constitute mainly sugar residues. The EPS is both homopolymer and heteropolymer supported their shape and size depend on degree of polymerization, derived from various microorganisms. Biosurfactants can be distinctive as the surface-bioactive biomolecules produced by microorganisms with broad array of applications. It has the viscoelastic quality maintained in the temperature range of 5–60 °C. Up to date, microbial EPS (biosurfactants) have found many applications including environmental remediation, pharmaceuticals, cosmetics, and food industry. First and foremost, the biosurfactants achieved a prospective interest for environmental applications of inorganic and organic contaminants, mainly in hydrocarbons, heavy metal removal from water and soil, enhanced oil recovery, and pharmaceutical products. The modified EPS act as suitable agent for biodegradation of textile dyes. It has potential and promising application in textiles, paper and pulp, coal, ceramic processing, health care and cosmetics, food industries, detergents, pesticide and herbicide formulation, uranium ore-processing and mechanical dewatering of peat, etc. The EPS and their derivatives which include alginate, dextran, gellan, pullulan, and xanthan are nontoxic, biodegradable drug carriers which help in drug delivery system. These molecules also exhibit immunomodulator, antibacterial, antioxidant, antibiofilm, antiviral, and antitumor activity and expand to scaffold engineering. The distinctive rheological properties of those molecules are helpful for jelly formation in food industry. It also acts as crystallization inhibitor which helps in ice-cream manufacturing, and their stable emulsion property maintains well-built emulsification indexes with soya bean oil and hydrocarbons. Thus, the biosurfactants act as multifunctional biomolecules with wide applications in various fields.
Article
A biosurfactant producing strain was isolated and the rhamnolipid type biosurfactant was extracted for soil washing of a synthetically and naturally hydrocarbon-contaminated soil. Following the primary screening, Pseudomonas aeruginosa strain R 4 was selected and the effect of the carbon and nitrogen source and the salinity on biosurfactant production was studied. Of the best results were observed for glucose as a carbon source, NH4Cl as a nitrogen source and salinity of 1.4%. The produced biosurfactant was a glycolipid type biosurfactant and reduced the surface tension to 32.5 mN/m with a critical micelle concentration (CMC) of 50 mg/L and production yield of 90 mg/L. Using produced biosurfactant, a pyrene desorption rate of 82% was observed in selected conditions for initial pyrene concentration of 200 mg/L.
Chapter
Cost-effective complete mineralization of recalcitrant organic waste pollutants from industrial effluents is a serious issue before environmentalists today. These organic wastes are discharged from chemical industries, refineries, and others, such as mining, paint industries, chemical and mineral extraction, and oils, in effluents that can be fatal and carcinogenic to humans. Generally, wastewater pollutant degradation is done by a physical, chemical, or biological method. Biochemical methods have been adapted for removing these organic pollutants. The bioremediation process does not generate by-product pollutant, making it a promising sustainable and cost-effective technique for the management of organic waste. In this chapter, we briefly discuss the available physical, chemical, and bioremediation techniques for handling organic pollutants.
Preprint
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The lipopeptide biosurfactants' chemical characteristics from the lactic acid bacteria isolated from milk and milk products were studied and their effect on maize plant growth. The oil displacement test was performed as a primary screening method to select the BS producing bacteria. Enterococcus faecium LM5.2 had the maximum emulsification index of 45.1±3 and reduced the surface tension to 32.98 ± 0.23% among all the isolates. E. faecium LM5.2 efficiently produced 945.26 ± 4.62 mg/l biosurfactants within 48 hours in MRS broth under the optimum conditions. The confirmation of the identity of the isolate LM5.2 was done with physiochemical tests and 16S rRNA gene sequencing. The molecular phylogenetic relationship was evaluated by the Neighbour-Joining phylogenetic method. The biosurfactant was purified by TLC and identified as lipopeptide-like iturines and surfactins based on R f values. Mass spectroscopy, NMR, and FTIR analysis also confirmed the biosurfactant's identity as the derivatives of iturin and surfactin. Both the biosurfactant and its producer bacterium were evaluated for their plant growth-promoting activity, and it was found that the biosurfactant and the bacterium could enhance plant growth. To the best of our knowledge, this is the first report of lipopeptide biosurfactant production from Enterococcus faecium . Moreover, the study also showed that the biosurfactant and biosurfactant producing E. faecium LM5.2 could be an eco-friendly plant growth-promoting agent.
Chapter
In the eon of industrialization, the scrutiny of natural resources has apportioned as a rising root in analyzing advanced science and technologies to produce materials like surfactants in an accumulated manner receiving great deals in the International market. Immense classification of tensioprogressive biomolecules with voluminous properties known as surfactants, which will be produced by both synthetic and biological methods, are useful in major areas of industrial sectors. Biologically (from microorganisms) imitative surfactants, i.e., biosurfactants can joust with synthetic surfactants due to their biodegradable, less toxic, and stable properties over a huge uncertainty in environmental factors. Nonetheless, now synthetic surfactants are widely used in different industrial areas as the only option for their availability in large amounts, unlike biosurfactants. A new species of pollutants cause environmental disasters by the usage of the wrong selection of synthetic surfactants. Therefore, driving toward economical and ecofriendly pathways, biosurfactants stood as more promising materials rather than synthetic surfactants that are chemically processed. Here, the focus has been intensified on biosurfactant applications in a wide range of industries. This chapter, therefore, intends to explain the classification, properties, and significance of biomolecules to play a crucial role in lubrification, mineral floatation, and petroleum recovery, which are desirable qualities in many industrial sectors.
Conference Paper
This investigation presents laboratory and field deployment results that demonstrate the potential candidacy utilizing Nano and bio-technologies to create superior chemicals for novel applications to increase oil recovery from both onshore and offshore reservoirs. Nano-technology is gaining momentum as a tool to improve performance in multiple industries, and has shown significant potential to enhance hydrocarbon production. The laboratory analysis and specifically designed coreflood results indicate there are beneficial interactions at liquid-nano solid interface that increase oil mobility. This will increase the surface activity of chemical surfactants and thereby make them the dominant agents to mobilize and recover oil from oil-bearing reservoirs. Advances in biotechnology offer another rich resource of knowledge for surface active materials that are renewable and more environmental-friendly. In addition, our studies also demonstrate that bio-surfactants are well-suited to provide superior performances in enhancing oil recovery. Nano-particles and biosurfactants may be included with synthetic surfactants to create novel and more efficient surface active agents for enhanced oil recovery. These formulations can promote better flow back of the injected stimulation fluids and additional mobilization to extract more oil from the matrix and micro-fractures. Laboratory experiments demonstrate that the specialized surfactant formulations created, interact with mixed or oil-wet low permeability formations to produce additional oil. Furthermore, this investigation also compares the total production on a candidate field with respect to typical water flood and the novel formulated surfactant approach. For each surfactant treatment, the overall designed injected fluid volume is 1500 m3 (~ 396,000 gallons) with 4 gpt (gallon per thousand unit) of surfactant concentration. Results indicate improved oil production with longer exposure time of the key surfactants within the reservoir. Enhanced surface wetting and super-low interfacial tension (IFT) at lower chemical concentrations are recognized to be the main mechanisms. The novel surfactant also shows stronger sustainability and endurance in keeping rock surface wettability over traditional surfactant system up to 5 times for an 8 PV wash. Furthermore, this can assist to identify and initiate the optimization of the identified mechanisms for potential applications within other compatible reservoirs. A number of successful field applications of EOR with special formulated nano and bio-based surfactant formulation are discussed in this paper. This unique study bridges the gap between the field realized results and lab optimization to enhance feasibility as a function of time and cost.
Article
Biosurfactants are surface active, amphiphilic, multifunctional, non-toxic and biodegradable alternatives to chemical surfactants. The present study reported biosurfactant production from yeast Debaryomyces hansenii CBS767 using soybean oil as the low-cost carbon source. Characterization of extracellularly synthesized biosurfactant revealed it as of glycolipid type. D. hansenii was able to synthesize the biosurfactant at diverse physiochemical conditions of temperature, pH, percentage of soyabean oil and incubation period. Isolated cell free extract displayed reducing activity as evident by synthesis of silver nanoparticles of size between 23.7 and 77.5 nm. This reducing action might be due to the presence of certain reducing metabolites in cell extract. Silver nanoparticles displayed distinct spherical morphology. This implies surface functionality of the biosurfactant as capping agent helping in regulating the process of nanoparticle aggregation. To aid the future optimization of biosurfactant production from D. hansenii, five support vector machine models were developed, trained and evaluated utilizing experimental optimization datasets. Significant prediction of E24, oil displacement and surface tension using these models encourage the use of machine learning in the future assessment of biosurfactant production.
Article
In the present study, the efficiency of four different strains of Pseudomonas aeruginosa and their biosurfactants in the bioremediation process were investigated. The strains were found to be capable of metabolizing a wide range of hydrocarbons (HCs) with preference for high molecular weight aliphatic (ALP) over aromatic (ARO) compounds. After treating with individual bacteria and 11 different consortia, the residual crude oils were quantified and qualitatively analyzed. The bacterial strains degraded ALP, ARO, and nitrogen, sulphur, oxygen (NSO) containing fractions of the crude oil by 73–67.5, 31.8–12.3 and 14.7–7.3%, respectively. Additionally, the viscosity of the residual crude oil reduced from 48.7 to 34.6–39 mPa s. Further, consortium designated as 7 and 11 improved the degradation of ALP, ARO, and NSO HCs portions by 80.4–78.6, 42.7–42.4 and 21.6–19.2%, respectively. Moreover, addition of biosurfactant further increased the degradation performance of consortia by 81.6–80.7, 43.8–42.6 and 22.5–20.7%, respectively. Gas chromatographic analysis confirmed the ability of the individual strains and their consortium to degrade various fractions of crude oil. Experiments with biosurfactants revealed that polyaromatic hydrocarbons (PAHs) are more soluble in the presence of biosurfactants. Phenanthrene had the highest solubility among the tested PAHs, which further increased as biosurfactant doses raised above their respective critical micelle concentrations (CMC). Furthermore, biosurfactants were able to recover 73.5–63.4% of residual oil from the sludge within their respective CMCs. Hence, selected surfactant-producing bacteria and their consortium could be useful in developing a greener and eco-sustainable way for removing crude oil pollutants from soil.
Article
Biosurfactants, in comparison to chemical surfactants, have a greater impact on various applications due to their stability, degradability, and other physicochemical characteristics. Increasing yield and lowering production costs are critical to enhancing biosurfactant efficiency. Because biosurfactant production costs are determined by the least expensive substrate, agro-based industrial waste is one of the most promising economic strategies. Therefore, in this study we aimed to achieve the biosurfactant production in Pseudomonas aeruginosa by low cost rice medium using Response surface methodology (RSM) and assessed their competence in controlling the Fusarium wilt of Abelmoschus esculentus. Initially, the selected strain P. aeruginosa PBS29 was confirmed using 16S rRNA sequencing. Then, the 20 % (v/v) of rice water was chosen as the cheapest carbon source for formulating rice water medium to optimize biosurfactant production using Central Composite Design. Enhanced biosurfactant yield of 9.35 g/l was attained through RSM by 0.59 fold higher than preliminary analysis. The model was significant with a regression coefficient of 0.98. The optimal condition was identified as 1.18% (w/v) nitrogen source [glutamic acid], pH 6.8, temperature at 37.4 °C, 2.5% (v/v) inoculum size, and 167.9 rpm agitation. In-vitro antifungal activity and biocontrol strategy of the biosurfactant demonstrated against Fusarium wilt of Abelmoschus esculentus at 100 μg/ml concentration by both soil drenching and foliar spray by pot trial. Furthermore, the detection of rhl gene, TLC, FT-IR, HPLC and GC-MS analyses suggested that the biosurfactant is rhamnolipid. Overall, in this study, the biosurfactant was synthesized using inexpensive rice water and substantiated its safe use as a biocontrol agent, which will help large-scale commercialization and interchange chemical surfactant used in agricultural wastes.
Article
Polymer hydrolysis polyacrylamide and microbes have been used to enhance oil recovery in many oil reservoirs. However, the application of this two-method combination was less investigated, especially in low permeability reservoirs. In this work, two bacteria, a rhamnolipid-producing Pseudomonas aeruginosa 8D and a lipopeptide-producing Bacillus subtilis S4, were used together with hydrolysis poly-acrylamide in a low permeability heterogeneous core physical model. The results showed that when the two bacterial fermentation liquids were used at a ratio by volumeof 1:3 (v:v), the mixture showed the optimal physicochemical properties for oil-displacement. In addition, the mixture was stable under the conditions of various temperature (20–70 °C) and salinity (0–22%). When the polymer and bacteria were mixed together, it had no significant effects in the viscosity of polymer hydrolysis polyacrylamide and the viability of bacteria. The core oil-displacement test displayed that polymer hydrolysis polyacrylamide addition followed by the bacterial mixture injection could significantly enhance oil recovery. The recovery rate was increased by 15.01% and 10.03%, respectively, compared with the sole polymer hydrolysis polyacrylamide flooding and microbial flooding. Taken together, these results suggest that the strategy of polymer hydrolysis poly-acrylamide addition followed by microbial flooding is beneficial for improving oil recovery in heterogeneous low permeability reservoirs.
Article
Microbial enhanced oil recovery (MEOR), due to the formation of biofilm and the presence of biosurfactants generated by microorganisms in the reservoir, can play a role in reducing interfacial tension (IFT) and wettability alteration. In this work, the fluid-fluid interaction by measuring the IFT has been evaluated for combining two EOR methods, including low salinity water and MEOR, due to the high importance of fluid-fluid interaction in EOR. Geobacillus stearothermophilus has been used as a bacterium to study changes in IFT. The effect of different salts, including monovalent and divalent cations and anions at different salinities, on biosurfactant performance, is investigated using IFT measurements. Also, the type of oil is evaluated in terms of its acidic and basic properties on the performance of biosurfactants. According to the results of this study, injection of Geobacillus stearothermophilus bacteria reduces interfacial tension in acidic oil by 10.26% and in basic oil by 5.26%. According to the results, increasing salinity in the presence of oil-containing asphaltene with basic properties increases the IFT of the solution containing Geobacillus stearothermophilus bacteria, but in the presence of acidic oil, a decrease in IFT is observed. The most significant effect of reducing the IFT of acidic oil and solution containing Geobacillus stearothermophilus is obtained in the presence of the following salts, respectively: CaCl2>MgCl2>NaCl. The results show that with increasing CaCl2 concentration, the IFT between basic oil and Geobacillus stearothermophilus solution gradually increases. This ascending trend is in the presence of NaCl salt with a lower slope. However, in the presence of MgCl2 salt, dual behavior is observed before and after the concentration of 1000 ppm, so that before this concentration, the IFT increases and then decreases. The findings of this study can help for a better understanding of the interaction of bacteria with asphaltenic oils in the presence of effective salts for low salinity water injection. The results of this study showed that by combining low salinity water with bacteria, less IFT could be obtained than low salinity water or bacteria alone.
Chapter
Sustainable agriculture is one among the trending disputes worldwide. The economically viable and environmentally sound practicing of farming provides better crop production and stable ecosystem. Subsequently, weed control have become an area of concern that gradually reduce the sustainability in a ubiquitous way. The current upgradation with the advent of emerging technology and advances in invasive weed control is the use of biologically dependent control measures as bioherbicides for biological weed control. Because of its high degree of precision against target weeds, little impact on nonhost species, lack of residual build-up in the ecosystem and usefulness in the control of herbicide resistant weed populations; it has gained important strategy over conventional herbicides. Yet, host changeability, environmental restrictions and reliability in formulation development provoked challenging constraints against bioherbicides. An augmentation brought out to smoothen out these issues faced by bioherbicides; Inclusion of an adjuvant in terms of biosurfactants literally modifies the action of the bioherbicides by their synergistic effect toward controlling weed growth by affixing the unique traits of surfactants generated by microorganisms. Biosurfactants lend proper stability in maintaining emulsions, counteract with temperature and pH limitations, retain the wettability to resist evaporation, sustains the inoculum nutrient balance till it performs complete action contrarily it gets degraded by UV radiations. The symbiotic effect of bioherbicides – surfactants gave out hopeful backlash for an effective weed management system.
Article
Biosurfactants have biological origin that are widely known as surface active agents. Different classes of biosurfactant has high importance in both the biotechnological and microbiological arena. Pseudomonas aeruginosa, Bacillus subtilis and Candida sp. are important classes of microorganisms that are highly investigated for the production of rhamnolipids (RLs) biosurfactants. Rhamnolipids have unique surface activity and gained interest in various industrial applications. Due to their high biodegradability, renewability and functionally maintenance at extreme conditions microbial biosurfactants are more advantageous than chemical based biosurfactants. Biosurfactants produced by microorganisms are potential candidate for the biodegradation, environmental cleanup of pollutants and also has some role in the heavy metal removal of metallurgical industries. Therefore, a greater attention has been paid on biosurfactants and identifying their potential applications for further studies.
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Herein we report the structure and selected properties of a new class of biosurfactants that we have named the flavolipids. The flavolipids exhibit a unique polar moiety that features citric acid and two cadaverine molecules. Flavolipids were produced by a soil isolate, Flavobacterium sp. strain MTN11 (accession number AY162137), during growth in mineral salts medium, with 2% glucose as the sole carbon and energy source. MTN11 produced a mixture of at least 37 flavolipids ranging from 584 to 686 in molecular weight (MW). The structure of the major component (23%; MW = 668) was determined to be 4-[[5-(7-methyl-(E)-2-octenoylhydroxyamino)pentyl]amino]-2-[2-[[5-(7-methyl-(E)-2-octenoylhydroxyamino)pentyl]amino]-2-oxoethyl]-2-hydroxy-4-oxobutanoic acid. The partially purified flavolipid mixture isolated from strain MTN11 exhibited a critical micelle concentration of 300 mg/liter and reduced surface tension to 26.0 mN/m, indicating strong surfactant activity. The flavolipid mixture was a strong and stable emulsifier even at concentrations as low as 19 mg/liter. It was also an effective solubilizing agent, and in a biodegradation study, it enhanced hexadecane mineralization by two isolates, MTN11 (100-fold) and Pseudomonas aeruginosa ATCC 9027 (2.5-fold), over an 8-day period. The flavolipid-cadmium stability constant was measured to be 3.61, which is comparable to that for organic ligands such as oxalic acid and acetic acid. In summary, the flavolipids represent a new class of biosurfactants that have potential for use in a variety of biotechnological and industrial applications.
Article
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The biodegradation of oil products in the environment is often limited by their low water solubility and dissolution rate. Rhamnolipids produced by Pseudomonas aeruginosa AT10 were investigated for their potential to enhance bioavailability and hence the biodegradation of crude oil by a microbial consortium in liquid medium. The characterization of the rhamnolipids produced by strain AT10 showed the effectiveness of emulsification of complex mixtures. The addition of rhamnolipids accelerates the biodegradation of total petroleum hydrocarbons from 32% to 61% at 10 days of incubation. Nevertheless, the enhancement of biosurfactant addition was more noticeable in the case of the group of isoprenoids from the aliphatic fraction and the alkylated polycyclic aromatic hydrocarbons (PHAS) from the aromatic fraction. The biodegradation of some targeted isoprenoids increased from 16% to 70% and for some alkylated PAHs from 9% to 44%.
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Microbially produced biosurfactants were studied to enhance crude oil desorption and mobilization in model soil column systems. The ability of biosurfactants from Rhodococcus ruber to remove the oil from the soil core was 1.4-2.3 times greater than that of a synthetic surfactant of suitable properties, Tween 60. Biosurfactant-enhanced oil mobilization was temperature-related, and it was slower at 15 degrees C than at 22-28 degrees C. Mathematical modelling using a one-dimensional filtration model was applied to simulate the process of oil penetration through a soil column in the presence of (bio)surfactants. A strong positive correlation (R(2)=0.99) was found between surfactant penetration through oil-contaminated soil and oil removal activity. Biosurfactant was less adsorbed to soil components than synthetic surfactant, thus rapidly penetrating through the soil column and effectively removing 65-82% of crude oil. Chemical analysis showed that crude oil removed by biosurfactant contained a lower proportion of high-molecular-weight paraffins and asphaltenes, the most nonbiodegradable compounds, compared to initial oil composition. This result suggests that oil mobilized by biosurfactants could be easily biodegraded by soil bacteria. Rhodococcus biosurfactants can be used for in situ remediation of oil-contaminated soils.
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Biosurfactant-producing bacteria were isolated from terrestrial and marine samples collected in areas contaminated with crude oil or its byproducts. Isolates were screened for biosurfactant/bioemulsifier production in different carbon sources (glucose, fructose, sucrose and kerosene) using the qualitative drop-collapse test. Glucose produced the highest number of positive results (17 of 185 isolates). All 17 isolates produced emulsions with kerosene and 12 exhibited high emulsion-stabilizing capacity, maintaining 50% of the original emulsion volume for 48 h. Eight of the 17 isolates reduced the growth medium surface tension below 40 mN m(-1) with 5 exhibiting this capacity in cell-free filtrates. Onset of biosurfactant production differed among the isolates, with some initiating synthesis during the exponential growth phase and others after the stationary phase was reached. Increasing temperature from 25 to 35 degrees C accelerated onset of biosurfactant production in only two isolates while pH (6.5-7.6) had no effect in any isolate tested. Isolation from petroleum contaminated sites using the screening protocol presented proved to be a rapid and effective manner to identify bacterial isolates with potential industrial applications.
Article
We studied the growth, biosurfactant activities and petroleum hydrocarbon compounds utilisation of strain 28-11 isolated from a solid waste oil. The isolate was identified as Bacillus pumilus. It grew well in the presence of 0.1% (w/v) of crude oil and naphthalene under aerobic conditions and utilised these substances as carbon and energy source. The capacity of strain 28-11 to emulsify crude oil and its ability to remove hydrocarbons looks promising for its application in environmental technologies.
Article
Pseudomonas aeruginosa J4, isolated from wastewater of a petrochemical factory located in southern Taiwan, was used to produce rhamnolipid from a variety of carbon substrates, including hydrophilic substrates, vegetable oils, and mineral oils. The P. aeruginosa J4 strain was able to assimilate the seven carbon substrates examined (namely, glucose, glycerol, olive oil, sunflower oil, grape seed oil, diesel, and kerosene), whereas it grew less efficiently in mineral oils (esp., kerosene). Rhamnolipid production from the J4 strain was affected by temperature and agitation rate, as 30°C and 200rpm agitation were favorable for rhamnolipid production. The rhamnolipid concentration (CRL) and production rate (vRL) was also influenced by the carbon sources used to grow the J4 strain. Similar vRL (10–12mg/h/L) and CRL (1400–2100mg/L) were obtained from using glycerol, glucose, grape seed oil, and sunflower oil as the sole carbon substrate, while using olive oil delivered the best rhamnolipid production. Maximum CRL (3600mg/L) and vRL (26mg/h/L) were attained at 10% olive oil. P. aeruginosa J4 also utilized diesel and kerosene for rhamnolipid production but with much lower CRL and vRL values Rhamnolipid was purified (nearly 90% pure) from the culture broth. Mass spectrometry and NMR analysis indicate that the purified product contained two types of commonly found rhamnolipids: l-rhamnosyl-β-hydroxydecanoyl-β-hydroxydecanoate (RL1) and l-rhamnosyl l-rhamnosyl-β-hydroxydecanoyl-β-hydroxydecanoate (RL2). The rhamnolipid product can reduce the surface tension of water to 31mN/m with a critical micelle concentration of nearly 50mg/L. The biosurfactant also achieved a maximum emulsion index of 70 and 78%, for diesel and kerosene, respectively, at a low concentration of about 300mg/L.
Article
AlnA is a 35.77kDa protein responsible for the hydrocarbon emulsifying and solubilizing activity of the Acinetobacter radioresistens KA53 bioemulsifier alasan. Deletion and substitution derivatives of AlnA were produced by site-directed polymerase chain reaction (PCR) mutagenesis and then used to study their ability to solubilize phenanthrene. AlnA contains four hydrophobic regions. Deletions of three or more amino acids from the hydrophobic N-terminus of AlnA caused a large decrease in solubilizing activity, whereas deletions from the C-terminus of 4, 7, 18 and 35 amino acids resulted in the loss of only 9, 22, 35 and 46% of the activity, respectively. Deletions of any of the three internal hydrophobic regions of AlnA caused a greater than 50% loss in solubilizing activity. The solubilizing activity of chimeric proteins, containing sequences from both AlnA and the homologous (but not surface active) Escherichia coli outer membrane protein A (OmpA), indicated that the most important sequences needed for solubilizing phenanthrene are on the N-terminal half of AlnA, especially the two hydrophobic loops (amino acids 37–45 and 164–171) on the β-barrel structure. Gel electrophoresis experiments demonstrated that AlnA and derivatives which retained high phenanthrene-solubilizing activity formed 210kDa complexes in the presence of phenanthrene. The relationship between AlnA structure and its surface activity is discussed.
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Nitrate-reducing bacterial strains (Pseudomonas sp. BS2201, BS2203 and Brevibacillus sp. BS2202) isolated from petroleum-contaminated soil were capable of degrading petroleum hydrocarbons under aerobic and anaerobic conditions. Under aerobic conditions (a 10-day experiment in liquid media) the strains degraded 20–25% of the total extractable material (TEM), including up to 90–95% of all alkanes analyzed (n-C10–C35). Under anaerobic conditions (a 50-day experiment) these organisms degraded 15–18% of the TEM, 20–25% of some alkanes, and 15–18% of selected polycyclic aromatic hydrocarbons. The strains also degraded saturated hydrocarbons under anaerobic conditions in the absence of nitrates as electron acceptors.
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A bibliographic review of hydrocarbon emulsifiers produced through biological processes.
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An investigation into the feasibility of using biosurfactant-rhamnolipid-fermentation liquor (RH) as a sacrificial agent was conducted in the laboratory and alkaline-surfactant-polymer (ASP)-flooding pilot test. The interfacial tensions (IFTs) between solutions containing biosurfactant or mixture of biosurfactant and alkylbenzene sulfonate (ORS) at different ratios and crude oil were studied at a constant NaOH concentration. The results show interfacial characteristics (IFT, interfacial viscosity and adsorption) of RH and significant synergic effect between RH and ORS. Adsorption isotherms of RH and ORS were determined to assess the effect of RH on reducing the adsorption of ORS on sandstone. Static adsorption experiments indicate that adsorption loss of ORS can be reduced by 25–30% when RH is mixed with ORS or pre-adsorbed on sandstone. The core-flooding tests show that the enhanced oil recovery with the formulation of ASP of 0.2 wt.% RH and 0.15 wt.% ORS (system 1) is 7% more than that with the formulation of ASP of only 0.15 wt.% ORS, and is equal to that with the formulation of ASP of 0.3 wt.% ORS. This indicates that using RH can reduce the cost of ASP flooding. The ASP-flooding pilot test was conducted with system 1 and resulted in 16.6%(OOIP) of the enhanced oil recovery in the whole test area.
Article
Oils from Buriti (Mauritia flexuosa), Cupuaçu (Theobroma grandiflora), Passion Fruit (Passiflora alata), Andiroba (Carapa guianensis), Brazilian Nut (Bertholletia excelsa) and Babassu (Orbignya spp.) were evaluated as carbon sources for rhamnolipid production by Pseudomonas aeruginosa LBI. The highest rhamnolipid concentrations were obtained from Brazilian Nut (9.9 g l-1) and Passion Fruit (9.2 g l-1) oils. Surface tension varied from 29.8 to 31.5 mN m-1, critical micelle concentration from 55 to 163 mg l-1 and the emulsifying activity was higher against toluene (93-100%) than against kerosene (70-92%). Preliminary characterization of the surfactant mixtures by mass spectrometry revealed the presence of two major components showing m/z of 649 and 503, which corresponded to the dirhamnolipid (Rha2C10C10) and the monorhamnolipid (RhaC10C10), respectively. The monorhamnolipid detected as the ion of m/z 503 is predominant in all samples analyzed.
Article
Liquid chromatography/mass spectrometry using electrospray ionisation was used to analyse rhamnolipids produced by a Pseudomonas aeruginosa strain with mannitol or naphthalene as carbon source. Identification and quantification of 28 different rhamnolipid congeners was accomplished using a reverse-phase C(18) column and a 30 min chromatographic run. Isomeric rhamnolipids that were not chromatographically resolved could be identified by interpretation of their mass spectra and their relative proportions estimated. The most abundant rhamnolipid produced on mannitol contained two rhamnoses and two 3-hydroxydecanoic acid groups. The most abundant rhamnolipid produced from naphthalene contained two rhamnoses and one 3-hydroxydecanoic acid group.
Article
Oil pollution is an environmental problem of increasing importance. Hydrocarbon-degrading microorganisms, adapted to grow and thrive in oil-containing environments, have an important role in the biological treatment of this pollution. One of the limiting factors in this process is the bioavailability of many fractions of the oil. The hydrocarbon-degrading microorganisms produce biosurfactants of diverse chemical nature and molecular size. These surface-active materials increase the surface area of hydrophobic water-insoluble substrates and increase their bioavailability, thereby enhancing the growth of bacteria and the rate of bioremediation.
Article
Using three typical nonionic surfactants (Tween80, Tween20 and Triton X-100), the solubilization of four kinds of polycyclic aromatic hydrocarbons (PAHs) e.g. naphthalene, phenanthrene, fluorene and pyrene, were characterized. It was found that not only nonionic surfactants could enhance the solubilization of PAHs greatly in the range of concentration above critical micellar concentration (CMC), but also the solubility had the linear relationship with the concentration of nonionic surfactants. The effect of solubilization enhancement at three surfactants was Triton X-100 > Tween80 > Tween20. In the three nonionic surfactants solution the micelle-aqueous phase partitioning coefficient (K(m)) had very good linear proportional to the octanol-water partitioning coefficient (Kow) for the four tested PAHs.
Article
The main commercial use of biosurfactants is in pollution remediation because of their ability to stabilize emulsions. This enhances the solubility and availability of hydrophobic pollutants, thus increasing their potential for biodegradation. One useful property of many biosurfactants that has not been reviewed extensively is their antimicrobial activity. Several biosurfactants have strong antibacterial, antifungal and antiviral activity. Other medically relevant uses of biosurfactants include their role as anti-adhesive agents to pathogens, making them useful for treating many diseases and as therapeutic and probiotic agents. Here, we discuss some of the new and exciting applications and related developments of various microbial surfactants in the field of biomedical sciences.
Article
We studied the growth, biosurfactant activities and petroleum hydrocarbon compounds utilisation of strain 28-11 isolated from a solid waste oil. The isolate was identified as Bacillus pumilus. It grew well in the presence of 0.1% (w/v) of crude oil and naphthalene under aerobic conditions and utilised these substances as carbon and energy source. The capacity of strain 28-11 to emulsify crude oil and its ability to remove hydrocarbons looks promising for its application in environmental technologies.
Article
Biosurfactants are surfactants that are produced extracellularly or as part of the cell membrane by bacteria, yeasts and fungi. Examples include Pseudomonas aeruginosa which produces rhamnolipids, Candida (formerly Torulopsis) bombicola, one of the few yeasts to produce biosurfactants, which produces high yields of sophorolipids from vegetable oils and sugars and Bacillus subtilis which produces a lipopeptide called surfactin. This review includes environmental applications of these biosurfactants for soil and water treatment. Biosurfactant applications in the environmental industries are promising due to their biodegradability, low toxicity and effectiveness in enhancing biodegradation and solubilization of low solubility compounds. However, more information is needed to be able to predict and model their behaviour. Full scale tests will be required. The role of biosurfactants in natural attenuation processes has not been determined. Very little information is available concerning the influence of soil components on the remediation process with biosurfactants. As most of the research until now has been performed with rhamnolipids, other biosurfactants need to be investigated as they may have more promising properties.
Article
During screening for biosurfactant-producing bacteria, a strain designated J36T was isolated from oil-polluted site near Kaohsiung city located in southern Taiwan. Cells of this organism were gram-negative rods motile by means of a single polar flagellum. Strain J36T grew well in complex media under optimum conditions of 35 degrees C and pH 7. The extracellular products of the strain expressed emulsification activity. During cultivation on olive oil as the sole carbon and energy source, the culture supernatant of strain J36T reduced surface tension of the medium from 68 to 32.6 dyne/cm. The 16S rRNA gene sequence analysis indicates that strain J36T is a member of Xanthomonas group within the gamma-Proteobacteria. The organism belongs to the genus Pseudoxanthomonas and represents a novel species within this genus according to phylogenetic analysis of 16S rDNA sequences, DNA-DNA similarity data, whole-cell protein analysis, physiological and biochemical characteristics, as well as fatty acid compositions. The predominant cellular fatty acids of strain J36T were 15:0 iso (about 26%), 17:1 iso omega9c (about 25%), and 15:0 anteiso (about 10%). Its DNA base ratio was 60.1 mol% G+C. We propose to classify strain J36T (= BCRC 17375T = LMG 22530T) as Pseudoxanthomonas kaohsiungensis sp. nov.
Article
An Aeromonas spp. was isolated from tropical estuarine water. The organism grew on crude oil and produced biosurfactant that could emulsify hydrocarbons. The peak growth and biosurfactant production was on the 8th day. The organism grew on a range of hydrocarbons that include crude oil and hexadecane while no growth was recorded on some hydrocarbons that include benzene. The biosurfactant produced by the organism emulsified a range of hydrocarbons with diesel (E24=65) as the best substrate and hexane (E24=22) as the poorest. After purification, the biosurfactant was found to contain about 38% carbohydrate and an unidentified lipid. No protein was present in the purified biosurfactant. Production of biosurfactant was highest in medium with glucose and lowest in the medium with diesel+acetate. Soybean was the best nitrogen source for biosurfactant production. The activity of the biosurfactant was enhanced optimally at NaCl concentration of 5%, pH of 8.0 and temperature of 40 degrees C. The biosurfactant retained 77% of its original activity after 120 min of exposure to heat at a temperature of 100 degrees C. Biosurfactant may be produced with this organism using non-hydrocarbon substrates such as glucose and soybean that are readily available and would not require extensive purification for use in food and pharmaceutical industries.
Article
The efficacy of a new rhamnolipid biosurfactants mixture to enhance the removal of pyrene from a soil artificially contaminated was investigated. The molar solubilization ratio (MSR) and the partition coefficient between the micelles and water (log K(m)) were found to be 7.5 x 10(-3) and 5.7, respectively. From soil column studies, the pyrene removal increased linearly with the concentration of the injected biosurfactants solution above the effective critical micellar concentration (0.4 g L(-1)). Flushing with a 5.0 g L(-1) biosurfactants solution increased the pyrene concentration in the effluent by 178 times. At high biosurfactants' concentrations (2.5 and 5.0 g L(-1)), the cumulative pyrene recovery reached 70%. This pyrene remobilization takes place independently of the soil organic carbon solubilization. This study provides a combination of batch and column experiments in order to find the conditions for effective soil remediation using a new rhamnolipids mixture.
Article
The production and properties of a biosurfactant, synthesized by Bacillus subtilis LB5a strain, using cassava wastewater as substrate were investigated. The microorganism was able to grow and to produce surfactant on cassava waste, reducing the surface tension of medium to 26.6 mN/m and giving a crude surfactant concentration of 3.0 g/L after 48 h. The surface-active compound retained its properties during exposure to elevate temperatures (100 degrees C), high salinity (20% NaCl) and a wide range of pH values. The surfactant was capable of forming stable emulsions with various hydrocarbons. Preliminary chemical characterization revealed that the surfactant has a lipopeptide composition with a CMC value of about 33 mg/L. Cassava wastewater proved to be a suitable substrate for biosurfactant biosynthesis, providing not only bacterial growth and product accumulation but also a surfactant that has interesting and useful properties with potential for many industrial applications.
Article
The impacts of surfactants (Tween80, Trition X-100, LAS and SDS) on PAHs degradation by white-rot fungi in aqueous system and soil-water system were studied. Results show that the type and concentration of surfactants, PAHs statues, pH value of the systems and temperature have impacts on the degradation of PAHs. In aqueous system, all the four surfactants restrained the degradation of PAHs. In soil-water system, Trition X-100 and SDS restrained the degradation of PAHs, while the impacts of Tween80 and LAS on PAHs degradation were influenced by the concentration of the surfactants. Low concentration Tween80 and LAS didn't promote the degradation of PAHs, and even played minor effects of restrain. But the degradation of PAHs could be enhanced with the increasing of the concentrations of Tween80 and LAS to certain levels. However, Tween80 and LAS with significant higher concentrations didn't show higher abilities on the promotion of PAHs degradation.
Article
The aim of this work was to study chemical structures and biological activities of rhamnolipids produced by Pseudomonas aeruginosa B189 isolated from milk factory waste. The culture produced two biosurfactants, a and b, which showed strong activity and were identified as L-rhamnopyranosyl-L-rhamnopyranosyl-beta-hydroxydecanoyl-beta-hydroxydecanoate or Rha-Rha-C10-C10 and L-rhamnopyranosyl-L-rhamnopyranosyl-beta-hydroxydecanoyl-beta-hydroxydodecanoate or Rha-Rha-C10-C12, respectively. Both compounds exhibited higher surfactant activities tested by the drop collapse test than several artificial surfactants such as SDS and Tween 80. Rhamnolipid a showed significant antiproliferative activity against human breast cancer cell line (MCF-7) at minimum inhibitory concentration (MIC) at 6.25 microg/mL while rhamnolipid b showed MIC against insect cell line C6/36 at 50 microg/mL.
Article
The applicability of the combined solubilization-biodegradation process was examined using soil-packed column. In the solubilization step, 50 pore volumes of 150 mg/l biosurfactants solution was injected and the percentage removal of phenanthrene (mg) was 17.3% and 9.5% from soil with pH 5 and 7, respectively. The highest solubility was detected at pH 5 and this result confirmed that adjusting the pH of the biosurfactants solution injected could enhance the solubility of phenanthrene. Following this, soil samples were completely transferred to batches and incubated for 10 weeks to monitor phenanthrene degradation. The phenanthrene concentration in the soil samples decreased significantly during the biodegradation step in all soil samples, except for the soil sample that was flushed with biosurfactants solution with pH 4. This indicated that the degradation of contaminants by specific species might not be affected by the residual biosurfactants following application of the solubilization process. Moreover, these results suggested that the biosurfactant-enhanced flushing process could be developed as a useful technology with no negative effects on subsurface environments and could be combined with the biodegradation process to increase the removal efficiency.
Article
The efficiency of Bacillus subtilis DM-04 and Pseudomonas aeruginosa M and NM strains isolated from a petroleum contaminated soil sample from North-East India was compared for the biodegradation of crude petroleum-oil hydrocarbons in soil and shake flask study. These bacterial strains could utilize crude petroleum-oil hydrocarbons as sole source of carbon and energy. Bioaugmentation of TPH contaminated microcosm with P. aeruginosa M and NM consortia and B. subtilis strain showed a significant reduction of TPH levels in treated soil as compared to control soil at the end of experiment (120 d). P. aeruginosa strains were more efficient than B. subtilis strain in reducing the TPH content from the medium. The plate count technique indicated expressive growth and biosurfactant production by exogenously seeded bacteria in crude petroleum-oil rich soil. The results showed that B. subtilis DM-04 and P. aeruginosa M and NM strains could be effective for in situ bioremediation.
Article
Biodegradation rates of PAHs are typically low at mesophilic conditions and it is believed that the kinetics of degradation is controlled by PAH solubility and mass transfer rates. Solubility tests were performed on phenanthrene, fluorene and fluoranthene at 20 degrees C, 40 degrees C and 60 degrees C and, as expected, a significant increase in the equilibrium solubility concentration and of the rate of dissolution of these polycyclic aromatic hydrocarbons (PAHs) was observed with increasing temperature. A first-order model was used to describe the PAH dissolution kinetics and the thermodynamic property changes associated with the dissolution process (enthalpy, entropy and Gibb's free energy of solution) were evaluated. Further, other relevant thermodynamic properties for these PAHs, including the activity coefficients at infinite dilution, Henry's law constants and octanol-water partition coefficients, were calculated in the temperature range 20-60 degrees C. In parallel with the dissolution studies, three thermophilic Geobacilli were isolated from compost that grew on phenanthrene at 60 degrees C and degraded the PAH more rapidly than other reported mesophiles. Our results show that while solubilization rates of PAHs are significantly enhanced at elevated temperatures, the biodegradation of PAHs under thermophilic conditions is likely mass transfer limited due to enhanced degradation rates.
Article
Isolation and characterization of the surface active components from the crude biosurfactant produced by Streptococcus thermophilus A was studied. A fraction rich in glycolipids was obtained by the fractionation of crude biosurfactant using hydrophobic interaction chromatography. Molecular (by Fourier transform infrared spectroscopy) and elemental compositions (by X-ray photoelectron spectroscopy) were determined. Critical micelle concentration achieved was 20 g/l, allowing for a surface tension value of 36 mJ/m(2). Moreover, this glycolipid rich fraction was found to be an anti-adhesive and antimicrobial agent against several bacterial and yeast strains isolated from explanted voice prostheses. Further purification steps should be carefully analyzed as each purification step will increase the costs and decreases the amounts of biosurfactants recovered.
Article
Ten fungal species isolated from tar balls collected from the beaches of Oman were tested for their abilities to grow and degrade n-alkanes and crude oil. The abilities of Aspergillus niger, A. ochraceus and Penicillium chrysogenum to degrade n-alkanes (C13-C18), crude oil were compared and their mycelial biomass was measured. Significant differences were found in the utilization of C15, C16, C17 and C18 by the three fungi. Similarly, significant differences we found in the amount of biomass produced by the three fungi growing on C13, C17, C18 and crude oil. The correlation coefficient of biomass and oil utilization was not statistically significant for Aspergillus niger, significant for Aspergillus terreus and highly significant for P. chrysogenum.
Solubilization of phenanthrene by biosurfactant in pure water
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Fig. 6. Solubilization of phenanthrene by biosurfactant in pure water. H. Yin et al. / Process Biochemistry 44 (2009) 302–308
Structure characterization and physico-chemical properties of rhamnolipids produced by Pseudomonas O-2-2
  • Liang
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  • Wang
  • Lu Jr Xl
  • Zhang
Liang SK, Wang XL, Lu JR, Zhang QQ. Structure characterization and physico-chemical properties of rhamnolipids produced by Pseudomonas O-2-2. Fine Chem 2005;22:499–502.
Structure characterization and physico-chemical properties of rhamnolipids produced by Pseudomonas O-2-2
  • Liang
Environmental applications for biosurfactants
  • Mulligan