Sophorolipids Research Articles

Encapsulation nanoarchitectonics of glabridin with sophorolipid micelles for addressing biofilm hazards via extracellular polymeric substance permeation and srtA gene suppression

BackgroundBiofilm, a common drug-resistant phenotype of Staphylococcus aureus (S. aureus), demonstrates significant drug resistance and recurrence due to its extracellular polymeric substance (EPS) barrier and subsequent bacterial migration. Hence, there is an urgent need for effective solutions to mitigate the hazards posed by biofilms. ResultThis study developed a stable, low-toxicity multifunctional nanomicelle, GLA@SOL/EYL, by encapsulating glabridin (GLA) using sophorolipid (SOL) and egg yolk lecithin (EYL). Optimizations were performed for the hydration medium, the ratio of carrier materials to GLA, and EYL additions. GLA@SOL/EYL exhibited a particle size of 122.1 ± 0.8 nm and a surface potential of −66.4 ± 1.7 mV, endowing it with the ability to permeate biofilms EPS effectively. GLA@SOL/EYL encapsulated 98.3 ± 1.2 % of GLA and demonstrated a slow-release effect, significantly enhancing the bioavailability of GLA. The addition of EYL reduced the hemolytic toxicity of GLA@SOL/EYL and improved its encapsulation rate and stability. GLA@SOL/EYL reduced the minimum inhibitory concentration of GLA to 8 μg/mL and extended its inhibitory effect at low concentrations by rapidly disrupting the structural integrity of S. aureus. GLA@SOL/EYL may penetrate biofilms to disperse EPS and remove twice as much biofilm as GLA alone, thereby eliminating 99.99 % of S. aureus within biofilms, compared to 99 % bactericidal efficacy of GLA. Additionally, GLA@SOL/EYL inhibited 63.8 ± 1.8 % of biofilm formation by affecting the expression of the srtA gene, thereby reducing the expression of cell wall-anchoring protein genes. In contrast, the biofilm inhibition rates of GLA and blank micelles were less than 10 %. ConclusionGLA@SOL/EYL utilizes the nanoparticle effect to penetrate biofilms and deliver antimicrobial GLA. The SOL disperses the biofilm matrix while GLA is released to kill S. aureus, preventing bacterial dissemination and colonization. Thus, GLA@SOL/EYL presents an innovative strategy for effectively eradicating S. aureus biofilms and preventing new hazards in a one-step approach.

Sophorolipid: An Effective Biomolecule for Targeting Microbial Biofilms.

Biofilms are microbial aggregates encased in a matrix that is attached to biological or nonbiological surfaces and constitute serious problems in food, medical, and marine industries and can have major negative effects on both health and the economy. Biofilm's complex microbial community provides a resistant environment that is difficult to eradicate and is extremely resilient to antibiotics and sanitizers. There are various conventional techniques for combating biofilms, including, chemical removal, physical or mechanical removal, use of antibiotics and disinfectants to destroy biofilm producing organisms. In contrast to free living planktonic cells, biofilms are very resistant to these methods. Hence, new strategies that differ from traditional approaches are urgently required. Microbial world offers a wide range of effective "green" compounds such as biosurfactants. They outperform synthetic surfactants in terms of biodegradability, superior stabilization, and reduced toxicity concerns. They also have better antiadhesive and anti-biofilm capabilities which can be used to treat biofilm-related problems. Sophorolipids (SLs) are a major type of biosurfactants that have gained immense interest in the healthcare industries because of their antiadhesive and anti-biofilm properties. Sophorolipids may therefore prove to be attractive substances that can be used in biomedical applications as adjuvant to other antibiotics against some infections through growth inhibition and/or biofilm disruption.

Enhancing bioremediation of petroleum-contaminated soil by sophorolipids-modified biochar: Combined metagenomic and metabolomic analyses

In this study, sophorolipids (SLs)-modified biochar (BC-SLs) was used to enhance the bioremediation of petroleum hydrocarbons (PHs) contaminated soil. The biodegradation rate of petroleum hydrocarbons (PHs) by BC-SLs and BC treatments were 62.86 % and 52.64 % after 60 days of remediation experiments, respectively, higher than non-biochar treatment group (24.09 %). The metagenomic analysis showed that the abundance of petroleum-degrading bacteria Actinobacteria and Proteobacteria were increased by 3.8 % and 5.3 %, respectively in BC-SLs treatment, and the abundance of functional genes for PHs degradation, such as alkB, nidA and pcaG, were significantly increased by 12.85 %, 30.08 % and 21.01 %, respectively. The metabolomic analysis showed that BC-SLs facilitated the metabolic process of PHs, the microbial metabolism of petroleum hydrocarbons (PHs) became more active. Fatty acid degradation and polycyclic aromatic hydrocarbons (PAHs) degradation were up-regulated, indicating the promoting effect of the BC-SLs for PHs metabolism. The combined metagenomic and metabolomic analysis demonstrated the strong positive correlations between PHs metabolites and PHs-degrading bacteria, such as lauric acid vs. Actinobacteria, benzoic vs. Proteobacteria. The strong positive correlations between PHs metabolites and PHs-degrading genes were also observed, such as o-ehyltoluene vs. nahD, 4-isopropylbenzoic acid vs. etbAa. The modification of biochar with SLs increased the oxygen-containing functional groups on the surface of biochar. Meanwhile, the emulsification and solubilization of SLs promoted the bioavailability of PHs. The effects of BC-SLs on the nitrogen cycle during PHs remediation showed that it facilitated the accumulation of nitrogen-fixing genes, promoted nitrification but inhibited denitrification process. This study confirms that the application of BC-SLs is an effective remediation of PHs contamination and a sustainable method for controlling agricultural waste resources.

Polyetheramine enhanced biosurfactant/biopolymer flooding for enhanced oil recovery

The application of conventional alkali, surfactant and polymer in alkali/surfactant/polymer (ASP) flooding has exposed the inherent shortcomings of pollution and damage to reservoirs. Hence, finding new environmentally friendly alternatives is essential for the sustainable development of ASP flooding. In this paper, we proposed a novel ternary combination utilizing organic alkali polyetheramine, biosurfactant, and biopolymer as alternative chemical agents for ASP flooding. Specifically, the ASP system composed of polyetheramine D230, biosurfactant sophorolipid (SL) and biopolymer welan gum (WLG) exhibited excellent potential in improving oil recovery. The interfacial tension measurements proved that D230 could react with organic acids in crude oil to generate surface-active soaps, which cooperated with SL to reduce the oil–water interfacial tension to 10−2 mN/m. The rheological measurements demonstrated that the addition of D230 could increase the viscosity of low concentration WLG solution, but this phenomenon gradually disappeared with the rise of WLG concentration. Even at higher WLG concentration, D230 only caused a slight decrease in system viscosity, which facilitated the improvement of sweep efficiency. Emulsification and contact angle measurements indicated that D230/SL blend had outstanding emulsifying ability and successfully altered the quartz surface from oil-wet to water-wet. Core flooding experiments and micromodel experiments showed that the D230/SL/WLG system significantly enhanced oil recovery by 22.66 %, which was attributed to the high viscosity, low interfacial tension, excellent wettability reversal and emulsifying abilities of the system. The economic benefit assessment indicated that this ASP system has the potential to be economic, rendering it profitable even during periods of low oil prices. Furthermore, the EC50 value of 52,600 mg/L for D230/SL/WLG demonstrated its environmental friendliness.

Enhanced anaerobic digestion of food waste using purified lactonic sophorolipids produced by solid-state fermentation of molasses and oil waste: A circular approach

In the present work, the effect of pure lactonic sophorolipids (SL) on the anaerobic digestion of biowaste was investigated. For this purpose, crude SL were produced from organic waste (a mixture of molasses and winterization oil cake) through solid-state fermentation (SSF) in a 22L pilot-scale aerobic bioreactor using the yeast Starmerella bombicola as SL-producing microorganism. The crude material extracted from the SSF exhaust solid contained several forms of SL and it was purified using High-Performance Liquid Chromatography (HPLC) and characterized by means of Liquid Chromatography-Mass Spectrometry (LC-MS) yielding a high-purity C18 lactonic SL (>99%). This pure SL was used to enhance the batch anaerobic digestion of source-selected biowaste, mainly composed by kitchen waste. The best dosage of SL was in the range of 0.02–0.04 g SL/g TS, with an increment of methane yield of 41% in NmL/g VS. The presence of SL did not significantly alter the structure of the microbial community or general biodiversity. In summary, we propose a circular approach for waste valorisation in which different organic waste streams are combined in a biorefinery-like configuration, where the solid-state fermentation is used to produce SL and results in an enhanced bioenergy production.

The upcycling of waste frying oil and the effect on sophorolipid productivity

AbstractWaste frying oil (WFO) is a degraded form of oil that is produced from repeated exposure to high temperatures during cooking. Many research studies have focused on the use of recycled WFO. These studies are highly promoted because of the need to find new ways of reducing the negative impact of WFO on the environment. One of these studies focused on the production of sophorolipid (SL), a naturally derived eco‐friendly glycolipid biosurfactant. Unfortunately, the environmental and societal advantages brought about by the wide‐spread use of SL are offset by its high production cost. WFO is a high‐volume, inexpensive material that can be used as a substrate for SL production. As such, by utilizing WFO as a feedstock material cost reduction can be realized to improve large‐scale application potential. One drawback to the use of WFO is that its physical characteristics are different from fresh oil and its effect on SL productivity (g/day) has not been investigated. This research focused on the effect of acid value (AV), peroxide value (PV), and carbonyl value (CV) of WFO on SL productivity. It was confirmed that SL titers (111.1 vs. 106.7 g/L) did not differ significantly after using either fresh oil (CV <0.01) or WFO, respectively. In addition, this research also confirmed that higher WFO degradation required longer culture periods (from 6 days to 9 days) to reach comparable SL concentrations as that produced with fresh oil.

Preliminary study for Polycyclic aromatic Hydrocarbons mobilization from contaminated marine sediment using synthetic and natural surfactants

The persistent presence of Polycyclic Aromatic Hydrocarbons (PAHs) in soils and sediments due to their chemical properties requires new methods to mobilize and make them more available for remediation purposes. In this work, the evaluation of the abilities of eight different non-ionic sugar-based and totally biodegradable surfactants, such as synthetic alkyl polyglycosides (APGs), biological sophorolipids (SLs) and biological rhamnolipids (RLs), was conducted in order to provide a preliminary guideline for the selection of the surfactant and the technical approach for PAHs extraction from the sediment. The reference sample was a marine sediment collected from Bagnoli (Naples, Italy) that was characterized to evaluate the level of PAHs contamination, which resulted equal to 3.51 g Kg−1 of total PAHs in the sediment. By using surfactants solutions with a surfactant concentration five times greater than critical micelle concentration (Cs = 5x CMC), a preliminary washing test in batch configuration was conducted, then followed by multiple consecutive washes (MCW) of the sediment to assess the solubilization of PAHs from the sediment by the action of selected surfactants. The results show an evident advantage given by the employment of each studied surfactant in mobilizing PAHs, compared to distilled water as benchmark. In detail, the synthetic alkyl polyglycosides APG2 led to a 3.4 % of total PAHs mobilization in the preliminary washing test with a maximum peak of 9.8 % for a single compound. The MCW test demonstrates that more consecutive washes can increase the amount of total PAHs removed, with a similar contribution from each wash, and that biosurfactants can be more attractive after several washes thanks to the increased capacity of PAHs mobilization. Interestingly, the high efficiency of surfactant to mobilize PAHs makes the soil washing a more attractive technology for removing PAHs from the marine sediments.

Protective effects of microbial biosurfactants produced by Bacillus halotolerans and Candida parapsilosis on bleomycin-induced pulmonary fibrosis in mice: Impact of antioxidant, anti-inflammatory and anti-fibrotic properties via TGF-β1/Smad-3 pathway and miRNA-326

Idiopathic pulmonary fibrosis (IPF) is an irreversible disease which considered the most fatal pulmonary fibrosis. Pulmonary toxicity including IPF is the most severe adverse effect of bleomycin, the chemotherapeutic agent. Based on the fact that, exogenous surfactants could induce alveolar stabilization in many lung diseases, the aim of this study was to explore the effects of low cost biosurfactants, surfactin (SUR) and sophorolipids (SLs), against bleomycin-induced pulmonary fibrosis in mice due to their antioxidant, and anti-inflammatory properties. Surfactin and sophorolipids were produced by microbial conversion of frying oil and potato peel wastes using Bacillus halotolerans and Candida parapsilosis respectively. These biosurfactants were identified by FTIR, 1H NMR, and LC-MS/MS spectra. C57BL/6 mice were administered the produced biosurfactants daily at oral dose of 200 mg kg−1 one day after the first bleomycin dose (35 U/kg). We evaluated four study groups: Control, Bleomycin, Bleomycin+SUR, Bleomycin+SLs. After 30 days, lungs from each mouse were sampled for oxidative stress, ELISA, Western blot, histopathological, immunohistochemical analyses. Our results showed that the produced SUR and SLs reduced pulmonary oxidative stress and inflammatory response in the lungs of bleomycin induced mice as they suppressed SOD, CAT, and GST activities also reduced NF-κβ, TNF-α, and CD68 levels. Furthermore, biosurfactants suppressed the expression of TGF-β1, Smad-3, and p-JNK fibrotic signaling pathway in pulmonary tissues. Histologically, SUR and SLs protected against lung ECM deposition caused by bleomycin administration. Biosurfactants produced from microbial sources can inhibit the induced inflammatory and fibrotic responses in bleomycin-induced pulmonary fibrosis.

Updated component analysis method for naturally occurring sophorolipids from Starmerella bombicola

Sophorolipids (SLs) are promising glycolipid biosurfactants as they are easily produced and functional. SLs from microorganisms are comprised of mixtures of multiple derivatives that have different structures and properties, including well-known acidic and lactonic SL (ASLs and LSLs, respectively). In this study, we established a method for analyzing all SL derivatives in the products of Starmerella bombicola, a typical SL-producing yeast. Detailed component analyses of S. bombicola products were carried out using reversed-phase high-performance liquid chromatography and mass spectrometry. Methanol was used as the eluent as it is a good solvent for all SL derivatives. With this approach, it was possible to not only quantify the ratio of the main components of ASL, LSL, and SL glycerides but also confirm trace components such as SL mono-glyceride and bola-form SL (sophorose at both ends); notably, this is the first time these components have been isolated and identified successfully in naturally occurring SLs. In addition, our results revealed a novel SL derivative in which a fatty acid is bonded in series to the ASL, which had not been reported previously. Using the present analysis method, it was possible to easily track compositional changes in the SL components during culture. Our results showed that LSL and ASL are produced initially and that SL glycerides accumulate from the middle stage during the fermentation process.Key points• An easy and detailed component analysis method for sophorolipids (SLs) is introduced.• Multiple SL derivatives were identified different from known SLs.• A novel hydrophobic acidic SL was isolated and characterized.Graphical

Environmental evaluation of emerging bakery waste oil-derived sophorolipids production by performing a dynamic life cycle assessment

Sophorolipids (SLs) are promising biosurfactants that have gained significant attention due to their superior properties compared to their fossil-derived counterparts. However, the huge cost of the abstracts limits its massive production. This study investigates the viability of bakery waste oil (BWO) as an economically efficient and environmentally sustainable feedstock for SLs production. Although such waste valorisation minimizes the use of first-generation substrates, the systematic environmental impacts need to be assessed as the waste streams may introduce different materials and processes. For this reason, a dynamic life cycle assessment (dLCA) was employed to iteratively assess the environmental impacts of SLs production as technology evolved. To facilitate the comparison between each traversal, the functional unit (FU) is defined as the production of 1 kg of crude SLs. SimaPro software and Ecoinvent v3.5 database were used to perform the dLCA. Cumulative energy demand (CED), global warming potential (GWP), and ReCiPe 2016 Midpoint (H) methods were used as indicators. Surprisingly, this analysis reveals that the use of BWO as a feedstock for SLs production (15,803.3 MJ of CED and 1277.3 kg CO2 eq. of GWP) does not consistently lead to reduced environmental impacts compared to first-generation feedstocks like oleic acid (11,898.3 MJ of CED and 959.6 kg CO2 eq. of GWP). Then different pH regulators were added to improve the bioprocess and reduce the environmental impacts. Notably, the introduction of potassium hydroxide (KOH) as a pH regulator significantly decreased environmental footprints, with results showing a CED and GWP of 9301.1 MJ and 751.7 kg CO2 eq., respectively. In contrast, sodium hydroxide (NaOH) exacerbated these impacts, resulting in a higher CED (19,741.6 MJ) and GWP (1595.6 kg CO2 eq.). ReCiPe Midpoint results confirmed that the use of BWO significantly reduced the environmental impacts of chemicals, especially the first-generation feedstock, under the regulation of KOH. Finally, a comparison was made between the use of BWO and food waste as substrates, demonstrating that BWO has a greater potential for reducing environmental impact. Moreover, the study recommends that combining BWO and food waste, along with other productivity-enhancing techniques like fed-batch fermentation and in-situ separation, will further enhance the sustainability of SLs production.The findings from the dLCA framework provide valuable insights for achieving sustainable SLs production, simultaneously enhancing SLs yield and environmental friendliness. This study highlights the effectiveness of dLCA as a method to track and analyze emerging technologies, guiding them toward a sustainability pathway.

Biocompatibility of Brazilian native yeast-derived sophorolipids and Trichoderma harzianum as plant-growth promoting bioformulations

The replacement of agrochemicals by biomolecules is imperative to mitigate soil contamination and inactivation of its core microbiota. Within this context, this study aimed at the interaction between a biological control agent such as Trichoderma harzianum CCT 2160 (BF-Th) and the biosurfactants (BSs) derived from the native Brazilian yeast Starmerella bombicola UFMG-CM-Y6419. Thereafter, their potential in germination of Oryza sativa L. seeds was tested. Both bioproducts were produced on site and characterized according to their chemical composition by HPLC-MS and GC-MS for BSs and SDS-PAGE gel for BF-Th. The BSs were confirmed to be sophorolipids (SLs) which is a well-studied compound with antimicrobial activity. The biocompatibility was examined by cultivating the fungus with SLs supplementation ranging from 0.1 to 2 g/L in solid and submerged fermentation. In solid state fermentation the supplementation of SLs enhanced spore production, conferring the synergy of both bioproducts. For the germination assays, bioformulations composed of SLs, BF-Th and combined (SLT) were applied in the germination of O. sativa L seeds achieving an improvement of up to 30% in morphological aspects such as root and shoot size as well as the presence of lateral roots. It was hypothesized that SLs were able to regulate phytohormones expression such as auxins and gibberellins during early stage of growth, pointing to their novel plant-growth stimulating properties. Thus, this study has pointed to the potential of hybrid bioformulations composed of biosurfactants and active endophytic fungal spores in order to augment the plant fitness and possibly the control of diseases.

Handling the inhibitory role of product accumulation during sophorolipid fermentation in a bubble column reactor with an in situ foam recovery.

Sophorolipid (SL) production by Candida catenulata from sunflower fatty acids was studied in a bubble column reactor (BCR). The specific oxygen uptake rate was 0.021mggcell-1 min-1 which indicates the importance of aeration in SL biosynthesis. The measurement of oxygen transfer rate (OTR) in the BCR showed a satisfactory OTR value of about 0.093min-1 in the system. However, further SL production was stopped after 30h in the BCR mainly due to the product accumulation in the culture and its inhibitory effects on cell growth and SL synthesis. Since an extensive foam was generated in the BCR under the absence of an antifoam agent, the development of an in situ foam recovery system provided the integration of production and separation of SL to handle the problem. The application of the foam recovery system enhanced biomass and titer SL concentration by 38.5 and 28.2% in comparison with the conventional BCR, respectively. Further studies in the system were performed by monitoring the size of bubbles and their effects on the biomass and SL enrichment in the foam stream at different aeration rates where the SL enrichment varied from 900 to 100% at 12 and 50h of the fermentation.

Study on the production of Sophorolipid by Starmerella bombicola yeast using fried waste oil fermentation.

Sophorolipids (SLs) are surface active compounds that have excellent surface-lowering properties. SLs were produced by Starmerella bombicola (CGMCC1576) yeast with sunflower seed oil, fried waste oil, cooked tung oil and raw tung oil used as hydrophobic carbon sources. The results showed that the strain could use sunflower seed oil and fried waste oil as hydrophobic carbon sources to produce SLs, and the yields were 44.52 and 39.09 gl-1. It could not be used as cooked tung oil and raw tung oil. The analysis by high-performance liquid chromatography/high resolution mass spectrometry (HPLC-MS/MS) showed that the main composition and structure of SLs produced by fermentation using fried waste oil were similar to that of sunflower seed oil as hydrophobic carbon source. The yield of SLs was the highest when the fried waste oil was used as hydrophobic carbon source, glucose (8%), waste oil (6%) and yeast (0.3%). When fried waste oil was used as a hydrophobic carbon source in a parallel 4-strand fermentation tank (FT), the combination with the largest yield and the most cost saving was that 3% of fried waste oil was added into the initial medium, and another 3% was again added after 72 h of fermentation. The total yield of SLs was 121.28 gl-1, and the yield of lactone SLs was 48.07 gl-1.

Kinetic studies and dynamic modeling of sophorolipids production by Candida catenulata using different carbon sources

Abstract The kinetic study on sophorolipids (SLs) production by Candida catenulata from glucose, raw sunflower soapstock was investigated at different initial concentrations ranging from 0 to 100 g L−1. The Monod model with a maximum specific growth rate (μ max) of 0.0167 h−1 and half-saturation coefficient (K S ) of 6.91 g L−1 best described the cell growth kinetics of C. catenulata on glucose. The best-fitted constants of the Monod model for raw sunflower soapstock were μ max = 0.0157 h−1 and K S = 16.01 g L−1. Determination of Luedeking-Piret constants indicated SLs mainly produced as an associated growth product in the systems. Dynamic features of the fermentation were modeled using the obtained constants and results showed the prediction power of the developed model in describing the behavior of the process. Also, a modified kinetic model was developed for the dynamic modeling of the dual carbon sources system.

Carbon and nitrogen optimization in solid-state fermentation for sustainable sophorolipid production using industrial waste.

The use of alternative feedstocks such as industrial or food waste is being explored for the sustainable production of sophorolipids (SLs). Microbial biosurfactants are mainly produced via submerged fermentation (SmF); however, solid-state fermentation (SSF) seems to be a promising alternative for using solid waste or byproducts that could not be exploited by SmF. Applying the advantages that SSF offers and with the aim of revalorizing industrial organic waste, the impact of carbon and nitrogen sources on the relationship between yeast growth and SL production was analyzed. The laboratory-scale system used winterization oil cake as the solid waste for a hydrophobic carbon source. Pure hydrophilic carbon (glucose) and nitrogen (urea) sources were used in a Box-Behnken statistical design of experiments at different ratios by applying the response surface methodology. Optimal conditions to maximize the production and productivity of diacetylated lactonic C18:1 were a glucose:nitrogen ratio of 181.7:1.43(w w-1 based on the initial dry matter) at a fermentation time of 100h, reaching 0.54 total gram of diacetylated lactonic C18:1 with a yield of 0.047g per gram of initial dry mass. Moreover, time course fermentation under optimized conditions increased the SL crude extract and diacetylated lactonic C8:1 production by 22% and 30%, respectively, when compared to reference conditions. After optimization, industrial wastes were used to substitute pure substrates. Different industrial sludges, OFMSW hydrolysate, and sweet candy industry wastewater provided nitrogen, hydrophilic carbon, and micronutrients, respectively, allowing their use as alternative feedstocks. Sweet candy industry wastewater and cosmetic sludge are potential hydrophilic carbon and nitrogen sources, respectively, for sophorolipid production, achieving yields of approximately 70% when compared to the control group.

Acid-form Sophorolipids Exhibit Minimal Cytotoxicity, Similar to Solvents and Oils Used in Personal Care Products, despite Being Surfactants.

Surfactants are amphiphilic substances that induce surface tension reduction, washing, and emulsification and are used for various purposes. Recently, biosurfactants manufactured from renewable resources and with high biocompatibility have gained increasing attention. Sophorolipid (SL), a type of biosurfactant derived from Starmerella bombicola, possesses detergency and emulsification properties, making it suitable for household and personal care applications. However, there are limited toxicological data on SLs. In this study, we conducted cytotoxicity and skin-irritation tests using SLs, revealing that cytotoxicity and skin irritation induced by SLs were extremely low (logIC 50 = 4.76 mg/L) and equivalent to those of solvents and oils used in personal care products.

Multifunctional Biotechnological Lip Moisturizer for Lip Repair and Hydration: Development, In Vivo Efficacy Assessment and Sensory Analysis

The demand for sustainable cosmetics leads to the search for natural and biotechnological ingredients. The present study reports the development of a multifunctional lip moisturizer containing levan (LEV) from Bacillus subtilis natto, sophorolipids (SOPs) from Starmerella bombicola and Citrus paradisi (OCP) essential oil, using a simplex-centroid experimental design. The formulations were evaluated physicochemically, pharmacotechnically and by DPPH assay. The optimized formulation was selected through the Response Surface Method, and the evaluation of its efficiency in lip hydration was carried out using the bioimpedance method and sensory analysis. The formulations showed pH compatibility with lips and remained stable after a centrifuge test and thermal stress. Spreadability varied between 415.3 and 1217.1 mm2, moisture retention was above 95% and antioxidant capacity was around 50% for all formulations. The optimized formulation, containing 0.4% LEV and 0.8% SOF, maintained the lip hydration already shown by the participants; 85% of them reported improvement in this aspect. For the first time, LEV and SOP were incorporated in lip moisturizers, which is an environmentally friendly product with marketing potential. Furthermore, the use of the Skin Analyzer Digital equipment, a low-cost and non-invasive technique, to evaluate the effectiveness of lip products is innovative; this methodology may help in the development of future cosmetology studies.

The mechanistic interplay between Nrf-2, NF-κB/MAPK, caspase-dependent apoptosis, and autophagy in the hepatoprotective effects of Sophorolipids produced by microbial conversion of banana peels using Saccharomyces cerevisiae against doxorubicin-induced hepatotoxicity in rats

BackgroundDoxorubicin (DOX) is a well-known chemotherapeutic agent which causes serious adverse effects due to multiple organ damage, including cardiotoxicity, nephrotoxicity, neurotoxicity, and hepatotoxicity. The mechanism of DOX-induced organ toxicity might be attributed to oxidative stress (OS) and, consequently, activation of inflammatory signaling pathways, apoptosis, and blockage of autophagy. Sophorolipids (SLs) as a glycolipid type of biosurfactants, are natural products that have unique properties and a wide range of applications attributed to their antioxidant and anti-inflammatory properties. AimsProduction of low-cost SLs from Saccharomyces cerevisiae grown on banana peels and investigating their possible protective effects against DOX-induced hepatotoxicity. Main methodsThe yeast was locally isolated and molecularly identified, then the yielded SLs were characterized by FTIR, 1H NMR and LC-MS/MS spectra. Posteriorly, thirty-two male Wistar rats were randomly divided into four groups; control (oral saline), SLs (200 mg/kg, p.o), DOX (10 mg/kg; i.p.), and SL + DOX (200 mg/kg p.o.,10 mg/kg; i.p., respectively). Liver function tests (LFTs), oxidative stress, inflammatory, apoptosis as well as autophagy markers were investigated. Key findingsSLs were produced with a yield of 49.04% and treatment with SLs improved LFTs, enhanced Nrf2 and suppressed NF-κB, IL-6, IL-1β, p38, caspase 3 and Bax/Bcl2 ratio in addition to promotion of autophagy when compared to DOX group. SignificanceOur results revealed a novel promising protective effect of SLs against DOX-induced hepatotoxicity in rats.

Host Defense Peptide Piscidin and Yeast-Derived Glycolipid Exhibit Synergistic Antimicrobial Action through Concerted Interactions with Membranes.

Developing new antimicrobials as alternatives to conventional antibiotics has become an urgent race to eradicate drug-resistant bacteria and to save human lives. Conventionally, antimicrobial molecules are studied independently even though they can be cosecreted in vivo. In this research, we investigate two classes of naturally derived antimicrobials: sophorolipid (SL) esters as modified yeast-derived glycolipid biosurfactants that feature high biocompatibility and low production cost; piscidins, which are host defense peptides (HDPs) from fish. While HDPs such as piscidins target the membrane of pathogens, and thus result in low incidence of resistance, SLs are not well understood on a mechanistic level. Here, we demonstrate that combining SL-hexyl ester (SL-HE) with subinhibitory concentration of piscidins 1 (P1) and 3 (P3) stimulates strong antimicrobial synergy, potentiating a promising therapeutic window. Permeabilization assays and biophysical studies employing circular dichroism, NMR, mass spectrometry, and X-ray diffraction are performed to investigate the mechanism underlying this powerful synergy. We reveal four key mechanistic features underlying the synergistic action: (1) P1/3 binds to SL-HE aggregates, becoming α-helical; (2) piscidin-glycolipid assemblies synergistically accumulate on membranes; (3) SL-HE used alone or bound to P1/3 associates with phospholipid bilayers where it induces defects; (4) piscidin-glycolipid complexes disrupt the bilayer structure more dramatically and differently than either compound alone, with phase separation occurring when both agents are present. Overall, dramatic enhancement in antimicrobial activity is associated with the use of two membrane-active agents, with the glycolipid playing the roles of prefolding the peptide, coordinating the delivery of both agents to bacterial surfaces, recruiting the peptide to the pathogenic membranes, and supporting membrane disruption by the peptide. Given that SLs are ubiquitously and safely used in consumer products, the SL/peptide formulation engineered and mechanistically characterized in this study could represent fertile ground to develop novel synergistic agents against drug-resistant bacteria.

3D-printed biosurfactant-chitosan antibacterial coating for the prevention of silicone-based associated infections.

Infections associated with the surfaces of medical devices represent a critical problem due to biofilm formation and the growing resistance towards antibacterial drugs. This is particularly relevant in commonly used invasive devices such as silicone-based ones where a demand for alternative antibiofilm surfaces is increasing. In this work, an antimicrobial chitosan-biosurfactant hydrogel mesh was produced by 3D-printing. The 3D structure was designed to coat polydimethylsiloxane-based medical devices for infection prevention. Additionally, the porous 3D structure allows the incorporation of customized bioactive components. For this purpose, two biosurfactants (surfactin and sophorolipids) were biosynthesized and tested for their antimicrobial activity. In addition, the printing of surfactant-chitosan-based coatings was optimized, and the resulting 3D structures were characterized (i.e., wettability, FTIR-ATR, antimicrobial activity, and biocompatibility). Compared with surfactin, the results showed a better yield and higher antibacterial activity against Gram-positive bacteria for sophorolipids (SLs). Thus, SLs were used to produce chitosan-based 3D-printed coatings. Overall, the SLs-impregnated coatings showed the best antibacterial activity against Staphylococcus aureus planktonic bacteria (61 % of growth inhibition) and antibiofilm activity (2log units reduction) when compared to control. Furthermore, concerning biocompatibility, the coatings were cytocompatible towards human dermal fibroblasts. Finally, the coating presented a mesh suitable to be filled with a model bioactive compound (i.e., hyaluronic acid), paving the way to be used for customized therapeutics.