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Currently, Gramicidin S (GR-S) is produced enzymatically with the drawback of the presence of trifluoroacetic acid (TFA) or produced by fermentation involving several separation and purification steps. Therefore, this study is focused on the use of green solvents as unique extraction step to produce Gramicidin S from microbial biomass of Aneurinibacillus aneurinilyticus. Among the tested solvents, such as ethanol, acidic ethanol or buffer phosphate, the most favorable was acidic ethanol, extracting 96% of Gramicidin S from cells with a purity of 90%. Using acidic ethanol, extraction time within the range of 30-120 min exhibited minimal impact on Gramicidin S yield, whereas the biomass-to-extractant ratio emerged as a critical parameter. Gramicidin S extracts were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF-MS), and Electrospray Ionization Mass Spectrometry (ESI-MS) coupled with Ultra Performance Liquid Chromatography (UPLC) and compared with commercial Gramicidin S.

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BACKGROUND: This is a novel work that includes the use of a biosurfactant extract obtained from corn milling industry (named BS-CSW), with antimicrobial activity, as ingredient in formulations to treat acne vulgaris. METHODOLOGY: With this purpose, it was established an incomplete experimental design with 3 independent variables, based on the concentration of non-nano zinc oxide (ZnO) (0-2%), BS-CSW (0-5%) and salicylic acid (0-2%). RESULTS: This design allowed to obtain a theoretical model that calculates the inhibitory effect on Cutibacterium acnes (also named Propionibacterium acnes) for any formulation carried with the ingredients appointed before. It was observed a clear synergetic effect on the inhibition of C. acnes between ZnO and BS-CSW, in absence of salicylic acid. This fact allowed to reduce the concentration of ZnO, giving more ecofriendly and biocompatible formulations. CONCLUSIONS: It was observed that the biosurfactant extract, in formulations with intermediate concentration of ZnO (1%), possess an inhibitory effect on C. acnes considerably higher than ZnO alone and similar to ZnO (1%) with salicylic acid (1%). This fact demonstrates the enormous potential of this bioactive extract in antiacne formulations.

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This article includes an updated review of the classification, uses and side effects of surfactants for their application in the cosmetic, personal care and pharmaceutical industries. Based on their origin and composition, surfactants can be divided into three different categories: (i) synthetic surfactants; (ii) bio-based surfactants; and (iii) microbial biosurfactants. The first group is the most widespread and cost-effective. It is composed of surfactants, which are synthetically produced, using non-renewable sources, with a final structure that is different from the natural components of living cells. The second category comprises surfactants of intermediate biocompatibility, usually produced by chemical synthesis but integrating fats, sugars or amino acids obtained from renewable sources into their structure. Finally, the third group of surfactants, designated as microbial biosurfactants, are considered the most biocompatible and eco-friendly, as they are produced by living cells, mostly bacteria and yeasts, without the intermediation of organic synthesis. Based on the information included in this review it would be interesting for cosmetic, personal care and pharmaceutical industries to consider microbial biosurfactants as a group apart from surfactants, needing specific regulations, as they are less toxic and more biocompatible than chemical surfactants having formulations that are more biocompatible and greener.

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In winemaking, oenological tannins are used to preserve wine colour by enhancing the antioxidant activity, taking part in copigmentation, and forming polymeric pigments with anthocyanins. As a novel processing aid, in this study, a biosurfactant extract was evaluated as a solubilizing and stabilizing agent of anthocyanins in red wine. The biosurfactant extract under evaluation was obtained from a fermented residual stream of the corn milling industry named corn steep liquor (CSL). Two red winegrape varieties (Vitis vinifera L. cv. Aglianico and Cabernet sauvignon) were studied for anthocyanin content and profile, and colour traits, during simulated skin maceration for 7 days at 25 °C, as well as polymerization and copigmentation at the end of maceration. A model wine solution was used as a control, which was added either with the CSL biosurfactant or with four different oenological tannins (from grape skin, grape seed, quebracho, and acacia). The results showed that CSL biosurfactant addition improved the colour properties of skin extracts by the formation of more stable compounds mainly through copigmentation interactions. These preliminary results highlighted that the effectiveness of CSL biosurfactant is variety-dependent; however, there is no significant protection of individual anthocyanin compounds as observed for delphinidin and petunidin forms using quebracho tannin.

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In this work, five biosurfactant extracts, obtained from different sources, all of them with demonstrated antimicrobial properties, were characterized and subjected to a cytotoxic study using mouse fibroblast cells (NCTC clone 929). Biosurfactant extracts obtained directly from corn steep water (CSW) showed similar surfactant characteristics to those of the extracellular biosurfactant extract produced by Bacillus isolated from CSW and grown in tryptic soy broth, observing that they are amphoteric, consisting of viscous and yellowish liquid with no foaming capacity. Contrarily, cell-bound biosurfactant extracts produced from Lactobacillus pentosus or produced by Bacillus sp isolated from CSW are nonionic, consisting of a white powder with foaming capacity. All the biosurfactants possess a similar fatty acid composition. The cytotoxic test revealed that the extracts under evaluation, at a concentration of 1 g/L, were not cytotoxic for fibroblasts (fibroblast growth > 90%). The biosurfactant extract obtained from CSW with ethyl acetate, at 1 g/L, showed the highest cytotoxic effect but above the cytotoxicity limit established by the UNE-EN-ISO10993-5. It is remarkable that the cell-bound biosurfactant produced by L. pentosus, at a concentration of 1 g/L, promoted the growth of the fibroblast up to 113%.

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The cosmetic industry provides a wide variety of shampoos to treat dandruff, containing insoluble ingredients such as Zn pyrithione. However, the solubility of this active ingredient is quite limited in both water and oil media; thus, antidandruff formulations must include a large amount of chemically synthesized stabilizing ingredients to avoid their precipitation. In this work, the stabilization of Zn pyrithione in O/W emulsions using a biosurfactant (BS) extract and Tween 80 is studied. The study includes an incomplete factorial design based on the tea tree oil/water ratio and both surfactant and biosurfactant concentrations. The formulations are characterized in terms of particle size, stability after 30 days, and solubility of Zn pyrithione. The formulation that provided the most favorable results contains Tween 80 (5%) and BS extract (2.5%), with an O/W ratio of 0.01. This provides the smallest particle size (40.5 µm), good stability after 30 days (91.0%), and the highest solubility of Zn pyrithione (59%). The results obtained enable the use of the combination of BS extract and Tween 80 as bio/surfactants of antidandruff shampoo formulations, along with another antiseptic agent such as tea tree oil. Furthermore, this is the first work where a biosurfactant is considered to be a stabilizing agent in antidandruff formulations.

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The permeation of ten model drugs through silicone membrane was analysed to investigate the effect of the presence of a biosurfactant obtained from corn steep liquor. The ten selected pharmaceutical compounds were chosen to include a diverse range of physicochemical properties, such as variable hydrophobicities, pKa's, molecular masses and degrees of ionisation. When compared with compound permeation alone, the additional inclusion of biosurfactant in the donor phase altered the rate and extent of permeation. It significantly enhanced permeation for five of the compounds, whereas it decreased permeation for four of the compounds and remained approximately the same for the tenth compound. These effects were observed at both biosurfactant concentrations considered, namely 0.005 mg/mL, i.e. below the critical micellar concentration (CMC) and 0.500 mg/mL, i.e. above the CMC of the biosurfactant. Upon analysing permeation change with respect to physicochemical properties of the compounds, it was determined that compounds with a relative molecular mass below 200 resulted in an increase in permeation with biosurfactant present, and those above 200 resulted in a decrease in permeation with biosurfactant present. This effect was therefore attributed to the formation of a drug-biosurfactant interaction that enhanced permeation of smaller compounds, yet retarded permeation for those with a higher molecular mass. These in vitro findings can be considered an indication of potential novel formulation options that incorporate biosurfactant to create transdermal products that have bespoke permeation profiles.

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BACKGROUND: Recent studies have proven that biosurfactants (BS) obtained from controlled fermentation have shown surfactant and antimicrobial properties. In this work a biosurfactant extract obtained from a raw agroindustrial stream from the corn-milling industry was introduced into a drinkable probiotic yogurt containing Lactobacillus casei. RESULTS: The effect of the biosurfactant extract on the probiotic population was determined under different biosurfactant concentration, temperature, and time conditions. This extract was able to reduce the surface tension of water by 30 mN/m and it was observed that its addition to a drinkable probiotic yogurt did not negatively affect the biomass of L. casei during incubation. It also had a positive effect on the population of L. casei, increasing the growth of the probiotic bacterium in the yogurt under optimum temperature conditions for the growth of L. casei, in the range of 30-40 °C. Likewise, the biosurfactant extract did not modify the homofermentative pathway of L. casei; hence no acetic acid was detected in the presence of the biosurfactant extract in the drinkable yogurt. CONCLUSION: This is the first time that a biosurfactant extract, obtained from natural sources, has been introduced into a food product like a drinkable probiotic yogurt, producing a positive effect in the growth of probiotic bacterium. © 2018 Society of Chemical Industry.

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In this work a comparative bioadsorption study between a biocomposite consisting of hydrolysed vineyard pruning waste entrapped in calcium alginate spheres and non entrapped vineyard residue was carried out. Results have demonstrated that the biocomposite based on lignocellulose-calcium alginate spheres removed 77.3% of dyes, while non entrapped lignocellulose eliminated only removed 27.8% of colour compounds. The experimental data were fitted to several kinetic models (pseudo-first order, pseudo-second order, Chien-Clayton model, intraparticle diffusion model and Bangham model); being pseudo-second order the kinetic model that better described the adsorption of dyes onto both bioadsorbents. In addition, a morphological study (roughness and shape) of alginate-vineyard biocomposite was established under extreme conditions, observing significant differences between hydrated and dehydrated alginate-vineyard biocomposite. The techniques used to carry out this morphological study consisted of scanning electron microscopy (SEM), perfilometry and 3D surface analysis.

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A decontamination technique based on the utilization of a lipopeptide biosurfactant extracted from corn steep liquor has been developed to eliminate polycyclic aromatic hydrocarbons (PAHs) from sewage sludge. High concentrations of PAHs were used during experiments observing that 408.3 mg/kg of naphthalene was almost completely mobilized and biodegraded, only 1.7% of naphthalene remained in the sewage sludge, whereas anthracene and pyrene were reduced up to 51.7 and 69.4%, respectively. The biodegradation of PAHs was fitted to several kinetic models (zero- and first-order kinetic models), observing good correlation coefficient values when biodegradation was described by the first-order kinetic model. Experimental results suggest that biosurfactant extracted from corn steep liquor may have great potential, as an ecofriendly washing agent, for the treatment of sewage sludge contaminated with PAHs. Therefore, in situ application of natural biosurfactants may be considered to be a good remediation alternative as they are not hazardous for water and soil organisms.

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BACKGROUND: There is currently much interest in the use of natural biosurfactants and bioemulsifiers, mainly in the cosmetic, pharmaceutical and food industries. However, there are no studies on the optimization of the extraction conditions of cell-bound biosurfactants. In this work, a biosurfactant with emulsifier properties was extracted from Lactobacillus pentosus cells, under different extraction conditions, and characterized. RESULTS: During extraction, the most influential independent variable, concerning the emulsifying capacity of biosurfactant, was the operation time, followed by temperature and salt concentration. Biosurfactant from L. pentosus was evaluated by Fourier transform infrared spectroscopy and the composition of fatty acids was analyzed by gas chromatography-mass spectrometry. The hydrophobic chain of the biosurfactant from L. pentosus comprises 548 g kg(-1) linoelaidic acid (C18:2), 221 g kg(-1) oleic or elaidic acid (C18:1), 136 g kg(-1) palmitic acid (C16) and 95 g kg(-1) stearic acid (C18). In addition, emulsions of water and rosemary oil were stabilized with a biosurfactant produced by L. pentosus and compared with emulsions stabilized with polysorbate 20. CONCLUSION: The optimum extraction conditions of biosurfactant were achieved at 45 °C at 120 min and using 9 g kg(-1) of salt. In all the assays biosurfactant from L. pentosus yielded more stable emulsions and higher emulsion volumes than polysorbate 20.

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Hydrolyzed grape marc (HGM) is the solid residue generated after the acid hydrolysis of grape marc to obtain hemicellulosic sugars for biotechnological purposes. In this work, HGM containing cellulose and lignin was composted together with vinification lees to obtain plant substrates on a laboratory scale. The effects of temperature (in the range of 20-50 degrees C), concentration of vinification lees (5-100 g/100 g of hydrolyzed grape marc), and concentration of CaCO(3) on the final properties of the composted HGM were studied by means of an experimental plan with factorial structure. The interrelationship between dependent and operational variables was established by models including linear, interaction, and quadratic terms. The most influential variable on the C/N ratio and P, K and Mg contents of composted substrates was the vinification lees concentration followed by the temperature, whereas on Na content and electrical conductivity the most influential variable was the temperature followed by the vinification lees concentration. The results of the incubation experiments indicated that optimal conditions for obtaining plant substrates can be achieved by composting 1:1 mixtures of hydrolyzed grape marc and vinification lees, in the presence of 5 g of CaCO(3)/100 g of HGM. During composting the pH of the mixtures increased from 5.1-6.7 to 7.1-8.1, salinity and water-soluble carbon were reduced in most cases, and the initial phytotoxicity disappeared in all of the mixtures tested.

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Nowadays, there are no studies about the role of the major hemicellulosic sugars on the production of surface-active compounds by Lactobacillus pentosus, although it was demonstrated that the activity of these compounds can be related to the agricultural residue from which they come, as the sugar solutions obtained from different agricultural residues contain different types and ratios of hemicellulosic sugars. Therefore, in this work, an incomplete factorial design was employed to test the relationship between the type and the ratio of hemicellulosic sugars present in hydrolysates from agricultural residues and the activity of surface-active compounds (cell-bond biosurfactants and extracellular bioemulsifiers) produced by L. pentosus. This design allowed us to establish models (that include linear, interaction, and quadratic terms) between dependent and independent variables. The independent variables used and their variation limits were as follows: glucose concentration (0-10 g L(-1)), xylose concentration (5-15 g L(-1)), and arabinose concentration (0-10 g L(-1)), whereas the 13 dependent variables studied were based on the measurement of surface tension and emulsifying capability. After the study, it was found that the emulsifier capacity of extracellular bioemulsifiers produced by L. pentosus increases at high glucose and xylose concentrations, with glucose concentration as the most influential variable in the range studied. However, the increase of glucose in the absence of xylose produced biosurfactants with low surface activity, with, in this case, the xylose concentration as the most influential variable. Taking into account the xylose/glucose ratio, the best results were obtained with xylose/glucose ratios around 1.5-3.5, which can be found in hemicellulosic hydrolysates from trimming vine shoots or grape marc hydrolysates.

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This work demonstrates that the biosurfactant produced by Lactobacillus pentosus from grape marc hydrolysates can be successfully employed in reducing the water repellence of hydrophobic substrates, rather than chemical surfactants, as it can be produced from low-cost residual materials and it is less toxic than chemical surfactants. The method employed to measure the water repellence of the 11 plant substrates, consisting of pine bark, peat, and composts from various origins (biodegradable fraction of municipal solid waste, green waste, sewage sludge, manure, pine bark, and grape marc), was the molarity of ethanol droplet method (MED). Peat, pine bark, and the composts obtained from grape marc and pine bark were severely hydrophobic, having contact angles over 104 degrees , whereas the composts from municipal solid waste were less hydrophobic, with contact angles under 101 degrees . When hydrophobic substrates were treated with the biosurfactant from L. pentosus, the water repellence of the plant substrates was reduced in all but two cases (the least hydrophobic composts), achieving in most of the cases results better than those obtained using chemical surfactants.

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In this work, vinification lees from Galicia (Spain) were chemically analysed and compared with the composition of vinification lees from other regions and residues. Moreover, vinification lees were submitted to biological test employing cress, spring barley and ryegrass seeds. The evaluated vinification lees were rich in nutrients that are essential for plants, like P (2,520 mg kg(-1)), K (36,738 mg kg(-1)) and Mg (462 mg kg(-1)), but have low pH (3.9) and high C/N ratio. However, when vinification lees were submitted to biological tests, no germination was observed for garden cress and ryegrass seeds and almost no germination for spring barley seeds, showing the negative effect of discharging lees on crop fields.

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The wine industry generates a large amount of wastes, including grape marc and vinification lees. These substances can be used to produce enzymes or other food additives. Composting could be a successful strategy for the sustainable and complete recycling of grape marc. In this work, the mesophilic biodegradation of grape marc during 60 d under microaerobic conditions using several ratios of seeds, skin, and stem were studied. The presence of Penicillium spp. was detected at the beginning of the composting. Changes in chemical and biological parameters were evaluated. Biodegraded grape marc with stem showed the best organic matter properties (C/N ratio of 14 and N content of 37 g/kg) and a germination index of 155% for the growth of ray grass seeds. The results suggest that the biodegraded of grape marc could be used as fertilizer, especially for ray grass crops.

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To develop a cost-effective fermentation medium, biomass of Debaryomyces hansenii coming from xylitol production and corn steep liquor was evaluated for lactic acid production by Lactobacillus rhamnosus in glucose-containing media. Glucose consumption and lactic acid generation were followed using a variety of media made with different nutrient supplementation. Under selected conditions, media containing glucose, biomass of D. hansenii and corn steep liquor as unique components led to product yields similar to those obtained in a fully supplemented medium.

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