Figure 1 - uploaded by Elisabete Barbarino
Content may be subject to copyright.
Quantification of protein in three species of marine macroalgae (A) Porphyra acanthophora var. acanthophora , (B) Sargassum vulgare and (C) Ulva fasciata by the Lowry (Lwy) and Bradford (Bdf) methods, using bovine serum albumin (BSA) and casein (CAS) as protein standards in the calibration curves. Three variables evaluated: (i) the water volume used to incubate samples (1 and 4 mL); (ii) the length of the incubation period for the extraction of protein (6 and 12 h); and (iii) the use of a Potter homogenizer for grinding samples. All assays included the precipitation of protein with 25% TCA, in a proportion of 2.5:1 (TCA:homogenate). Mean ± S . D . ( n = 6).
Source publication
Comparison of data of protein content in algae is very difficult, primarily due to differences in the analytical methods employed.
The different extraction procedures (exposure to water, grinding, etc.), protein precipitation using different amounts of
25% trichloroacetic acid and quantification of protein by two different methods and using two pro...
Contexts in source publication
Context 1
... use of the Potter homogeniser produced remark- able differences in the extraction of protein for the three species tested. In all cases, significantly ( p < 0.001) higher concentrations of protein was obtained in the treatment with the use of the Potter homogeniser (Fig- ures 1A-C). For Sargassum vulgare ( Figure 1B Higher concentrations of protein were obtained when 4.0 mL of water was used for U. fasciata ( p < 0.001) ( Figure 1C), and a longer period of incubation (12 h) for S. vulgare ( p = 0.002) ( Figure 1B). ...
Context 2
... all cases, significantly ( p < 0.001) higher concentrations of protein was obtained in the treatment with the use of the Potter homogeniser (Fig- ures 1A-C). For Sargassum vulgare ( Figure 1B Higher concentrations of protein were obtained when 4.0 mL of water was used for U. fasciata ( p < 0.001) ( Figure 1C), and a longer period of incubation (12 h) for S. vulgare ( p = 0.002) ( Figure 1B). There were no differences for P. acanthophora var. ...
Context 3
... all cases, significantly ( p < 0.001) higher concentrations of protein was obtained in the treatment with the use of the Potter homogeniser (Fig- ures 1A-C). For Sargassum vulgare ( Figure 1B Higher concentrations of protein were obtained when 4.0 mL of water was used for U. fasciata ( p < 0.001) ( Figure 1C), and a longer period of incubation (12 h) for S. vulgare ( p = 0.002) ( Figure 1B). There were no differences for P. acanthophora var. ...
Context 4
... all cases, significantly ( p < 0.001) higher concentrations of protein was obtained in the treatment with the use of the Potter homogeniser (Fig- ures 1A-C). For Sargassum vulgare ( Figure 1B Higher concentrations of protein were obtained when 4.0 mL of water was used for U. fasciata ( p < 0.001) ( Figure 1C), and a longer period of incubation (12 h) for S. vulgare ( p = 0.002) ( Figure 1B). There were no differences for P. acanthophora var. ...
Context 5
... were no differences for P. acanthophora var. acan- thophora ( Figure 1A) incubated in wither 1.0 or 4.0 mL for 6 h ( p = 0.52). ...
Similar publications
Seasonal variation in marine macroalgal community structure was examined at the intertidal zones of Heuksando and Hongdo, Shinan, Korea, from July 2008 to May 2009. In total, 86 macroalgal species were identified, including 12 green, 19 brown, and 55 red algae; 67 species at Heuksando and 70 species at Hongdo, were observed. Annual seaweed biomass...
Citations
... Despite these promising attributes, protein extraction from algae involves several challenges, including efficient large-scale extraction techniques and overcoming the sensory and textural limitations that might affect consumer acceptance when used in food products, such as meat analogs. Advanced methods, such as mechanical crushing, ultrasonic sonication, and enzymatic treatment, are employed to enhance the yield and functionality of the extracted proteins [38][39][40][41]. These proteins can then be incorporated into meat analogs through extrusion, a process that texturizes them to replicate the fibrous structure of meat [42]. ...
The expanding field of alternative proteins represents a transformative approach to addressing global food security and sustainability challenges. Among these, fermentation-derived alternative proteins cultivated from microorganisms such as fungi, bacteria, and algae offer a promising avenue for sustainable protein production. This review explores the selection and utilization of raw materials to produce microbial proteins through fermentation processes. Critical raw materials include agricultural byproducts, industrial waste streams, and specifically designed feedstocks, which not only mitigate environmental footprint but also enhance the economic viability of production systems. The utilization of lignocellulosic biomass and molasses has demonstrated considerable promise, attributed to their abundant and renewable nature. The review underscored the necessity of exploring specific areas to enhance the viability of producing microbial protein from diverse raw materials. These areas include improving pre-treatment strategies to enhance substrate suitability for fermentation, optimizing fermentation processes for increased yield and reduced costs, and developing more resilient microorganisms capable of thriving on varied substrates. These strategies are crucial for advancing the production of alternative proteins through fermentation, in addition to raw material selection, which is vital in the scalability and sustainability of alternative protein production through fermentation, emphasizing the need for continued research and innovation in this field.
... Proteins biomolecules play a significant role in the overall metabolism. G. edulis contains high protein (Barbarino and Lourenço 2005). Among G. edulis treated with different concentrations of Cd, a significant decrease in protein content (2.58 ± 0.28 mg g-1 alga fresh wt) was recorded in alga cultured in Cd300 treatment, whereas alga grown in different concentrations of Cd with Si treatments showed a significant increase in protein content (Figure 4b). ...
This study investigates the potential of silicate to alleviate cadmium (Cd) toxicity in Gracilaria edulis, an agarophyte. Under various culture conditions spanning 21 days, alga was grown in control, Silicate (Si) medium, and different Cd concentrations (100, 200, and 300 mM) with or without Si100 mM and the effect was measured by photosynthesis O 2 evolution , relative growth rate (RGR), biomass, biochemical compositions such as chlorophyll a, phycobilipigments (phycocyanin, allophycocyanin, and phycoerythrin), carbohydrate, protein, lipid peroxidation and Cd accumulation. Cd, a toxic heavy metal, negatively impacts plant and algal growth and metabolism. In contrast, traditionally considered non-essential, Si has growth-promoting properties under various stress conditions. The present study reveals that Si significantly enhances photosynthesis except for Cd300. In Cd100, the photosynthetic O 2 evolution was 0.08 nM s −1 , whereas in Cd100 þ Si, it increased to 0.09 nM s −1. The Cd300 þ Si treatment exhibited a rate of 0.07 nM s −1 , but in Cd300, it was 0.05 nM s-1 on the 9th day of culture, and the rate was proportionately high on the 18 th day of culture. The RGR and biomass significantly improved, particularly when Cd100 was combined with Si. Alga shows a decrease in the chlorophyll a, phycobilin pigments, carbohydrate, and protein content when grown at Cd300 concentration but significantly increased when combined with Si treatment. Alga showed less carbohydrate content (0.30 ± 0.02) at Cd300 mM exposure, of which was increased by adding Si (Cd300 þ Si) to 0.34 ± 0.02 mg g −1 alga fresh wt. Cd uptake by the alga is high at Cd300 but considerably low at Cd100 þ Si and Cd200 þ Si concentrations. Malondialdehyde (MDA) level indicating lipid peroxidation-induced oxidative damage was significantly reduced in Si-treated Cd concentrations compared to heavy metal treatment alone. This study demonstrates that silicate can potentially mitigate the adverse effects of Cd on G. edulis by creating a favorable environment for its growth. Thus, it exhibits promise in alleviating Cd toxicity in G. edulis.
... Proteins biomolecules play a significant role in the overall metabolism. G. edulis contains high protein (Barbarino and Lourenço 2005). Among G. edulis treated with different concentrations of Cd, a significant decrease in protein content (2.58 ± 0.28 mg g-1 alga fresh wt) was recorded in alga cultured in Cd300 treatment, whereas alga grown in different concentrations of Cd with Si treatments showed a significant increase in protein content (Figure 4b). ...
... Protein quantification was conducted using the Bradford method. An extract was obtained from the dried macroalgae, following the protocol of Barbarino & Lourenço [35], with the addition of 1 mL of sodium hydroxide and centrifugation. The extract and TCA (25%) were added in a ratio of 2.5:1 (v/v) to precipitate the protein and kept in an ice-cold bath for 30 min. ...
Different fertilization regimes in biofloc systems influence the predominance of distinct bacterial populations, impacting water quality and organism performance. This study evaluates the growth and nutrient absorption of the macroalgae Ulva lactuca when cultivated in an integrated system with Penaeus vannamei and Oreochromis niloticus in chemoautotrophic and heterotrophic systems. The experiment lasted 45 days and comprised two treatments, each with three replicates: chemoautotrophic—utilizing chemical fertilizers; heterotrophic—employing inoculum from mature biofloc shrimp cultivation, supplemented with organic fertilizers. Each treatment consisted of three systems, each containing a 4 m3 tank for shrimp, 0.7 m3 for tilapia, and 0.35 m3 for macroalgae, with continuous water circulation between tanks and constant aeration. Water quality analyses were carried out during the experiment, as were the performances of the macroalgae and animals. The data were subjected to a statistical analysis. Results revealed an increase in macroalgae biomass and the removal of nitrate (57%) and phosphate (47%) during cultivation, with a higher specific growth rate observed in the chemoautotrophic treatment. Nonetheless, the heterotrophic treatment exhibited higher levels of protein in the macroalgae (18% dry matter) and phosphate removal rates (56%), along with superior maintenance of water quality parameters. Tilapia performance varied across treatments, with a higher final weight and weight gain recorded in the heterotrophic treatment. The recycling of water from an ongoing biofloc cultivation with organic fertilization demonstrated viability for macroalgae cultivation within an integrated system involving shrimp and fish.
... Furthermore, after freeze-drying, the cells become more aggregated, reducing the contact surface with the extracting solvent and potentially affecting the cell wall integrity [67,68]. The obtained results were in line with those of Barbino et al. [69] for the two macroalgae Sargassum vulgare and Chnoospora minima. ...
Abstract: In this study, the release of proteins and other biomolecules into an aqueous media from two red macroalgae (Sphaerococcus coronopifolius and Gelidium spinosum) was studied using eight different cell disruption techniques. The contents of carbohydrates, pigments, and phenolic compounds coextracted with proteins were quantified. In addition, morphological changes at the cellular level in response to the different pretreatment methods were observed by an optical microscope. Finally, the antioxidant capacity of obtained protein extracts was evaluated using three in vitro tests. For both S. coronopifolius and G. spinosum, ultrasonication for 60 min proved to be the most effective technique for protein extraction, yielding values of 3.46 ± 0.06 mg/g DW and 9.73 ± 0.41 mg/g DW, respectively. Furthermore, the highest total contents of phenolic compounds, flavonoids, and carbohydrates were also recorded with the same method. However, the highest pigment contents were found with ultrasonication for 15 min. Interestingly, relatively high antioxidant activities like radical scavenging activity (31.57-65.16%), reducing power (0.51-1.70, OD at 700 nm), and ferrous iron-chelating activity (28.76-61.37%) were exerted by the different protein extracts whatever the pretreatment method applied. This antioxidant potency could be attributed to the presence of polyphenolic compounds, pigments, and/or other bioactive substances in these extracts. Among all the used techniques, ultrasonication pretreatment for 60 min appears to be the most efficient method in terms of destroying the macroalgae cell wall and extracting the molecules of interest, especially proteins. The protein fractions derived from the two red macroalgae under these conditions were precipitated with ammonium sulfate, lyophilized, and their molecular weight distribution was determined using SDS-PAGE. Our results showed that the major protein bands were observed between 25 kDa and 60 kDa for S. coronopifolius and ranged from 20 kDa to 150 kDa for G. spinosum. These findings indicated that ultrasonication for 60 min could be sufficient to disrupt the algae cells for obtaining protein-rich extracts with promising biological properties, especially antioxidant activity.
... Algal proteins, encompassing a full spectrum of essential amino acids, emerge as a noteworthy alternative protein source (Lourenço et al., 2004;Barbarino and Lourenço, 2005;Becker, 2007;Safi et al., 2014). Algae stand out for their tendency not to be endemic and their abundance. ...
... The experiment was conducted with certain adjustments according to the method outlined by Barbarino and Lourenço (2005). Initially, 4ml of ultra-pure water was added to 50 mg of dry material, and left at 4 °C for 12 h. ...
The excessive proliferation of green algae in aquatic ecosystems threatens aquatic life, leading to oxygen depletion and water pollution. This study investigates two common green algae species, Ulva sp. and Cladophora sp., with potential in terms of protein and phenolic compounds. Cladophora sp. and Ulva sp. extracts were analyzed for total phenolic content using the Folin-Ciocalteau method. Despite lower phenolic content compared to specific plant species, both algae species exhibit various phenolic compounds. GC-MS analysis indicates the presence of major compounds such as limonene in Cladophora sp. and Tetradec-1-ene in Ulva sp., suggesting potential applications in the pharmaceutical and cosmetic industries. Despite modest protein amounts, the study emphasizes that algae, aligned with the increasing interest in plant-based nutrition, are a promising source for plant-based protein production. Ulva sp. and Cladophora sp. algae demonstrate potential as alternative protein sources and reservoirs of bioactive phenolic compounds from waste sources. This study pioneers further research in the food, pharmaceutical, and cosmetic industries to contribute to sustainable water resource utilization.
... The proteins were extracted by modifying the multiple procedures described by Barbarino, & Lourenço, (2005). Briefly, the total proteins were extracted by dissolving 2.5g of dried seaweed powder in 125 mL of deionized water and incubated for 16 hours in a shaking water bath. ...
... The TCA method of Berges, et al., (1993), as explained by Barbarino, & Lourenço, (2005), was used with some modifications. 2.4 mL of crude extract was mixed with 6 mL of 25% TCA and incubated for 30 minutes at 4°C, after which it was centrifuged at 6000 rpm for 2 hours. ...
Seaweeds contain many macronutrients including protein, therefore they can be utilized to fulfil the protein requirements of human beings. This research focused on extracting total protein in green seaweed Ulva anandii (Amjad et Shameel 1993), from the crude extracts, by using the trichloroacetic acid (TCA) and acetone precipitation methods, and the estimation of crude extract (water-soluble proteins), and those obtained from the two above-mentioned methods. The results indicate that the water-soluble proteins had the highest quantity (949.75µg/mL) followed by the TCA precipitation method (831µg/mL), while the acetone precipitation method had the least concentration of total protein (100 µg/mL). The study concludes that treatment with organic solvents lowers the quantity of protein extracted from U. anandii.
... The standard curve was then plotted, and the protein concentration was calculated. 35 ...
Wastewater effluent from the pharmaceutical, cosmetic, and chemical industries often contains pharmaceutical contaminants, making the reuse of wastewater a controversial practice. Physical and chemical methods have been unsuccessful in removing these pollutants on a large scale. Microalgal technology has been introduced as a promising tool to tackle this issue. This study evaluated the performance of Trichormus variabilis microalgae in removing three contaminants, namely ranitidine, tramadol, and gabapentin. Three concentrations of each compound were introduced into the microalgal culture medium. The effect of these pharmaceutical concentrations on growth, biomass production, photosynthetic pigments, and protein and lipid content was evaluated and compared with control cultures over 14 days. It was found that T. variabilis was able to remove 61–100% of these drugs. Moreover, the addition of 250 mg L–1 of ranitidine to the algae culture medium led to a 33.4% reduction in biomass growth. Adding 20 mg L–1 of tramadol and 200 mg L–1 of gabapentin caused 30% and 19.2% biomass reductions, respectively. The presence of 100 mg L–1 of gabapentin led to a 38% and up to 14% increase in chlorophyll and carotenoid content in comparison with the control, while the presence of the other drugs reduced the content of chlorophyll and carotenoid. On the other hand, the protein content increased by 254% in the culture media compared to the control media in the presence of 50 mg L–1 ranitidine. Regarding lipid concentration, 20 mg L–1 of tramadol had the most important effect by doubling the lipid content in T. variabilis in comparison with the control. In conclusion, these drugs could be removed to a significant extent by T. variabilis, which is promising for larger scale applications.
... Polyphenolic compounds like flavonoids (Singh et al. 2020), as well as pigments are some of the substances known to interfere with these assays either through interaction with assay reactants or light absorbance at wavelengths that overlap with those used in the assays. Seaweeds contain phlorotannins and phenolic terpenoids (Barbarino & Lourenço 2005;Cotas et al. 2020), as well as high quantities of salt which can potentially affect the results of such assays (Lucarini & Kilikian 1999). ...
... Accurate protein content estimation in both plant and algal samples can be difficult due to the presence of numerous bioactive substances that interfere with the measurements and are co-extracted along with proteins (Barbarino & Lourenço, 2005;Lucarini & Kilikian, 1999). Furthermore, many algae species accumulate large quantities of salt, which may also interfere with protein solubility and reduction reactions with copper cations (Lucarini & Kilikian, 1999). ...
... Furthermore, many algae species accumulate large quantities of salt, which may also interfere with protein solubility and reduction reactions with copper cations (Lucarini & Kilikian, 1999). There is also a potential problem of inefficient extraction from algae due to recalcitrant cell walls requiring extensive cell disruption methods to break and the presence of phycocolloidal substances that hinder protein solubility (Barbarino & Lourenço, 2005). Precipitation protocols are typically used to concentrate proteins while removing unwanted substances, rendering the sample more suitable for protein quantification. ...
Algae contain many compounds which are of interest to the pharmaceutical, agricultural and food industries, among others. Despite the potential for many applications, a quick, accurate and inexpensive method for characterising algae is lacking. The objective of this thesis was to investigate the ability to determine protein, carbohydrate and fatty acid contents in algae, using infrared spectroscopy. Algal samples were analysed using some of the most accurate chemical methods, by hydrolysing proteins and polysaccharides and quantifying the resulting amino acid and monosaccharide contents using chromatography techniques. Fatty acid contents were similarly quantified by extraction followed by gas chromatography. This data was subsequently used to calibrate spectral prediction models, using different infrared spectroscopies. The accuracy of protein prediction by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and near-infrared spectroscopy (NIR) using partial least squares regression (PLSR) was compared to traditional methods like N-protein ratios and colorimetric assays. DRIFTS, attenuated total reflectance (ATR) Fourier transform infrared spectroscopy (ATR) and NIR were also comparatively used to characterise seaweed carbohydrates. Fatty acid contents were studied using DRIFTS in both microalgae and seaweeds. Infrared spectroscopy coupled with PLSR was shown to be highly accurate in characterising algal biomass, provided a sufficiently robust library of calibration samples. These methods require little or no chemicals and are rapid and easy to use, making them both environmentally and economically attractive.
... The macroalgae extract was obtained using the methodology of Barbarino & Lourenço [32], with the addition of 1 mL of sodium hydroxide and centrifugation to prepare the crude extract for protein analysis. The macroalgae protein was analyzed using the Biuret method, following the methodology of Barbarino & Lourenço [32]. ...
... The macroalgae extract was obtained using the methodology of Barbarino & Lourenço [32], with the addition of 1 mL of sodium hydroxide and centrifugation to prepare the crude extract for protein analysis. The macroalgae protein was analyzed using the Biuret method, following the methodology of Barbarino & Lourenço [32]. The extract and trichloroacetic acid (TCA) (25%) were added in a ratio of 2.5:1 (v/v) to precipitate the protein and kept in an ice-cold bath for 30 min. ...
This study focused on evaluating the effect of different concentrations of nutrients and total suspended solids on the removal rate of nutrients and biocompounds from the macroalgae U. lactuca in an integrated system with the shrimp Penaeus vannamei in biofloc. The experiment lasted 45 days and included five treatments with three replicates each, with percentages of 0 (control), 25, 50, 75, and 100% biofloc inoculum (73.3 ± 5.7 and 325.0 ± 21.2 mg L−1 initial nitrate and solids, respectively, in the 100% inoculum), from a shrimp farm, resulting in different concentrations of solids and nutrients. The macroalgae were introduced into 280 L tanks at a density of 0.88 kg m−2, along with 200 shrimp m−3. The algae were separated by a floating structure. Water quality parameters were measured, and the nutrient removal rate was evaluated. The treatment with 75% inoculum showed a removal rate of 55.0 ± 4.0 and 31.0 ± 10.0% of nitrate and phosphate, respectively. There was no difference in macroalgae growth between the treatments; however, macroalgae grown in 75% inoculum had higher protein, chlorophyll-a, and lower ash values compared with the control. The use of macroalgae in integrated production with shrimp under the conditions of the treatment with 75% biofloc inoculum proved to be viable and sustainable.
