Extraction, Isolation and Biological Activity of Two Glycolipids from Bangia fusco-purpurea.

In order to explore the extraction and activity of macroalge glycolipids, six macroalgae (Bangia fusco-purpurea, Gelidium amansii, Gloiopeltis furcata, Gracilariopsis lemaneiformis, Gracilaria sp. and Pyropia yezoensis) glycolipids were extracted with five different solvents firstly. Considering the yield and glycolipids concentration of extracts, Bangia fusco-purpurea, Gracilaria sp. and Pyropia yezoensis were selected from six species of marine macroalgae as the raw materials for the extraction of glycolipids. The effects of the volume score of methanol, solid-liquid ratio, extraction temperature, extraction time and ultrasonic power on the yield and glycolipids concentration of extracts of the above three macroalgae were analyzed through a series of single-factor experiments. By analyzing the antioxidant activity in vitro, moisture absorption and moisturizing activity, the extraction process of Bangia fusco-purpurea glycolipids was further optimized by response surface method to obtain suitable conditions for glycolipid extraction (solid-liquid ratio of 1:27 g/mL, extraction temperature of 48 °C, extraction time of 98 min and ultrasonic power of 450 W). Bangia fusco-purpurea extracts exhibited a certain scavenging effect on DPPH free radicals, as well as good moisture-absorption and moisture retaining activities. Two glycolipids were isolated from Bangia fusco-purpurea by liquid-liquid extraction, silica gel column chromatography and thin-layer chromatography, and they showed good scavenging activities against DPPH free radicals and total antioxidant capacity. Their scavenging activities against DPPH free radicals were about 60% at 1600 µg/mL, and total antioxidant capacity was better than that of Trolox. Among them, the moisturizing activity of a glycolipid was close to that of sorbierite and sodium alginate. These two glycolipids exhibited big application potential as food humectants and antioxidants.

Exploration of Polysaccharides from Phyllanthus emblica: Isolation, Identification, and Evaluation of Antioxidant and Anti-Glycolipid Metabolism Disorder Activities.

Phyllanthus emblica is a natural medicinal herb with diverse bioactivities. Certain extracts from this herb have been confirmed to possess anti-glycolipid metabolic disorder activity. To further develop its utility value and explore its potential in combating glycolipid metabolic disorders, we designed a series of experiments to investigate the structure, antioxidant activity, and anti-glycolipid metabolic disorder activity of Phyllanthus emblica polysaccharides. In this study, we extracted and purified polysaccharides from Phyllanthus emblica and thoroughly analyzed their structure using various techniques, including NMR, methylation analysis, and surface-enhanced Raman spectroscopy. We investigated the hypolipidemic and anti-glycolipid metabolism disorder activity of Phyllanthus emblica polysaccharides for the first time utilizing oleic acid (OA) and advanced glycation end products (AGEs) as inducers. Additionally, the antioxidant activity of Phyllanthus emblica polysaccharides was assessed in vitro. These findings lay the groundwork for future investigations into the potential application of Phyllanthus emblica polysaccharides as an intervention for preventing and treating diabetes.

First Isolation and Structure Elucidation of GDNT-ß-Glu - Tetraether Lipid Fragment from Archaeal Sulfolobus Strains.

Due to their special chemical structure, tetraether lipids (TEL) represent essential elements of archaeal membranes, providing these organisms with extraordinary properties. Here we describe the characterization of a newly isolated structural element of the main lipids. The TEL fragment GDNT-ß-Glu was isolated from Sulfolobus metallicus and characterized in terms of its chemical structure by NMR- and MS-investigations. The obtained data are dissimilar to analogically derived established structures - in essence, the binding relationships in the polar head group are re-determined and verified. With this work, we provide an important contribution to the structure elucidation of intact TEL also contained in other Sulfolobus strains such as Solfulobus acidocaldarius and Sulfolobus solfataricus.

Seeking faster, alternative methods for glycolipid biosurfactant characterization and purification.

Biosurfactants have been investigated as potential alternatives for synthetic surfactants in several areas, for example, in environmental and pharmaceutical fields. In that regard, extensive research has been carried out with sophorolipids and rhamnolipids that also present various biological properties with therapeutic significance. These biosurfactants are obtained as complex mixtures of slightly different molecules, and thus when studying these microbial glycolipids, the ability to identify and purify the produced compounds is of extreme importance. This study aimed to develop improved methodologies for the identification, separation, and purification of sophorolipids and rhamnolipids. Therefore, an ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was modified to ensure faster characterization of both sophorolipids and rhamnolipids, enabling the identification and fragmentation pattern description of 10 and 13 congeners, respectively. The separation and purification of these biosurfactants was achieved with novel reversed-phase solid-phase extraction methods guaranteeing the isolation of different glycolipids, including those considered for their significant biological activity (e.g. antimicrobial, anticancer). It was possible to isolate sophorolipids and rhamnolipids with purity of 94% and 99%, respectively. The methods presented herein can be easily implemented and are expected to make purification of these biosurfactants easier, facilitating the study of their individual properties in further works.

Isolation and purification of glycoglycerolipids to induce apoptosis in breast cancer cells.

Monogalactosyldiacylglycerol (MGDG) is the most abundant type of glycoglycerolipid found in the plant cell membrane and mostly in the chloroplast thylakoid membrane. The amphiphilic nature of MGDG is attractive in pharmaceutical fields for interaction with other biological molecules and hence exerting therapeutic anti-cancer, anti-viral, and anti-inflammatory activities. In this study, we investigated the therapeutic efficacy of cyanobacteria derived MGDG to inhibit breast cancer cell growth. MGDG was extracted from a cyanobacteria Synechocystis sp. PCC 6803 followed by a subsequent fractionation by column chromatographic technique. The purity and molecular structure of MGDG were analyzed by nuclear magnetic resonance (NMR) spectroscopy analysis. The presence of MGDG in the extracted fraction was further confirmed and quantified by high-performance liquid chromatography (HPLC). The anti-proliferation activity of the extracted MGDG molecule was tested against BT-474 and MDA-MB-231 breast cancer cell lines. The in vitro study showed that MGDG extracted from Synechocystis sp. PCC 6803 induced apoptosis in (70 ± 8) % of BT-474 (p < 0.001) and (58 ± 5) % of MDA-MB-231 cells (p < 0.001) using ~ 60 and 200 ng/ml of concentrations, respectively. The half-maximal inhibitory concentration, IC50 of MGDG extracted from Synechocystis sp. PCC 6803 were (27.2 ± 7.6) and (150 ± 70) ng/ml in BT-474 and MDA-MB-231 cell lines, respectively. Quantification of caspase-3/7 activity using flow cytometry showed (3.0 ± 0.4) and (2.1 ± 0.04)-fold (p < 0.001) higher protein expressions in the MGDG treated BT-474 and MDA-MB-231 cells, respectively than untreated controls conferring to the caspase-dependent apoptosis. The MGDG did not show any significant cytotoxic side effects in human dermal fibroblasts cells. A commercially available MGDG control did not induce any apoptotic cell death in cancer cells substantiating the potential of the MGDG extracted from Synechocystis sp. PCC 6803 for the treatment of breast cancer cells through the apoptosis-mediated pathway.

Exploring the potential of chitosan-based particles as delivery-carriers for promising antimicrobial glycolipid biosurfactants.

Driven by the need to find alternatives to control Staphylococcus aureus infections, this work describes the development of chitosan-based particulate systems as carriers for antimicrobial glycolipids. By using a simple ionic gelation method stable nanoparticles were obtained showing an encapsulation efficiency of 41.1 ± 8.8 % and 74.2 ± 1.3 % and an average size of 210.0 ± 15.7 nm and 329.6 ± 8.0 nm for sophorolipids and rhamnolipids chitosan-nanoparticles, respectively. Glycolipids incorporation and particle size was correspondingly corroborated by FTIR-ATR and TEM analysis. Rhamnolipids chitosan nanoparticles (RLs-CSp) presented the highest antimicrobial effect towards S. aureus (ATCC 25923) exhibiting a minimal inhibitory concentration of 130 µg/mL and a biofilm inhibition ability of 99 %. Additionally, RLs-CSp did not interfere with human dermal fibroblasts (AG22719) viability and proliferation under the tested conditions. The results revealed that the RLs-CSp were able to inhibit bacterial growth showing adequate cytocompatibility and might become, after additional studies, a valuable approach to prevent S. aureus related infections.

Antibacterial Efficacy and Mechanism of Mannosylerythritol Lipids-A on Listeria monocytogenes.

Mannosylerythritol lipids-A (MEL-A) is a novel biosurfactant with excellent surface activity and potential biomedical applications. In this study, we explored the antibacterial activity and the underlying mechanisms of MEL-A against the important food-borne pathogen Listeria monocytogenes. The bacterial growth and survival assays revealed a remarkable antibacterial activity of MEL-A. Since MEL-A is a biosurfactant, we examined the cell membrane integrity and morphological changes of MEL-A-treated bacteria by biochemical assays and flow cytometry analysis and electron microscopes. The results showed obvious damaging effects of MEL-A on the cell membrane and morphology. To further explore the antibacterial mechanism of MEL-A, a transcriptome analysis was performed, which identified 528 differentially expressed genes (DEGs). Gene ontology (GO) analysis revealed that the gene categories of membrane, localization and transport were enriched among the DEGs, and the analysis of the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways demonstrated significant changes in the maltodextrin ABC transporter system and stress response system. Furthermore, the growth of L. monocytogenes could also be significantly inhibited by MEL-A in milk, a model of a real food system, suggesting that MEL-A could be potentially applied as an natural antimicrobial agent to control food-borne pathogens in the food industry.

Neutral Lipids, Glycolipids, and Phospholipids, Isolated from Sandfish (Arctoscopus japonicus) Eggs, Exhibit Anti-Inflammatory Activity in LPS-Stimulated RAW264.7 Cells through NF-κB and MAPKs Pathways.

Total lipids were extracted from sandfish (Arctoscopus japonicus), and then they were separated into the following three lipid fractions: neutral lipids, glycolipids, and phospholipids. In this study, we analyzed the lipid fractions of A. japonicus eggs and we determined their anti-inflammatory activity in RAW264.7 macrophage cells. In these three lipid-fractions, the main fatty acids were as follows: palmitic acid (16:0), oleic acid (18:1n-9), docosahexaenoic acid (DHA, 22:6n-3), and eicosapentaenoic acid (EPA, 20:5n-3). Among the lipid fractions, phospholipids showed the highest concentration of DHA and EPA (21.70 ± 1.92 and 18.96 ± 1.27, respectively). The three lipid fractions of A. japonicus significantly suppressed the production of NO in macrophages. Moreover, they also significantly inhibited the expression of iNOS, COX-2, IL-6, IL-1ß, and TNF-α, in a dose-dependent manner. Furthermore, the lipid fractions of A. japonicus suppressed the nuclear translocation of NF-κB p65 subunits in a dose-dependent manner. In addition, they attenuated the activation of MAPKs (p38, ERK1/2, and JNK) phosphorylation in LPS-stimulated RAW264.7 cells. These results indicate that all the lipid fractions of A. japonicus exert anti-inflammatory activity by suppressing the activation of NF-κB and MAPK pathways. Therefore, the lipid fractions of A. japonicus might be potentially used as anti-inflammatory agents.

Lipid Composition of Liposomal Membrane Largely Affects Its Transport and Uptake through Small Intestinal Epithelial Cell Models.

Lipid composition of liposomal bilayer should alter the cell response for permeability, transport, and uptake in small intestine. This work was done to investigate the transport and uptake of liposomes composed of docosahexaenoic acid-enriched phosphatidylcholine (PtdCho), phosphatidylserine (PtdSer), and sulfoquinovosyl diacylglycerol (SQDG) derived from marine products on multilamellar vesicles (MLV) in small intestinal epithelial cell models. The results showed that addition of PtdSer and SQDG as liposomal bilayer could improve the efficiency entrapment of liposomes. The liposomes containing PtdSer showed higher transport and uptake through both Caco-2 cell and M cell monolayers as compared to PtdCho-MLV. SQDG-containing liposomes exhibited only higher transport through M cell monolayer, while its uptake effect was higher both in Caco-2 cell and M cell monolayers. The results of experiments done with endocytosis inhibitors indicated that PtdCho-MLV must be transported via macropinocytosis and uptaken by phagocytosis in M cell monolayer model. PtdCho/PtdSer-MLV and PtdCho/SQDG-MLV might be transported and uptaken through M cell monolayer by phagocytosis. The result also indicated that PtdCho/SQDG-MLV could open the tight junction of small intestinal epithelial cell monolayers. Furthermore, our findings demonstrated that the surface status of cholesterol-containing liposomes were smooth, but they did not affect their transport and uptake through Caco-2 cell and M cell monolayers.

Separation of Glycolipids/Sphingolipids from Glycerophospholipids on TiO2 Coating in Aprotic Solvent for Rapid Comprehensive Lipidomic Analysis with Liquid Microjunction Surface Sampling-Mass Spectrometry.

In lipidomic analysis by direct mass spectrometry (MS), high abundance lipids with high ionizability (such as glycerophospholipids) would cause ion suppression to lipids with poor ionizability and low abundance (such as glycolipids, sphingolipids, or glycerides), which largely limits the detection coverage for lipidomics. In this work, TiO2-based liquid microjunction surface sampling (LMJSS) coupled with MS was used for separation of glycerides, phospholipids and glycolipids/sphingolipids in biological samples and rapid analysis of lipids in different classes with high lipidome coverage. We found that, in nonaqueous aprotic solvents, lipids with a glycosyl or sphingosine group could be selectively separated from lipids with a phosphate group (selectivity >10) after being coenriched on TiO2 by tuning the solvent composition. Accordingly, a selective multistep extraction method was developed by loading the biosamples on TiO2 slides in neutral aprotic solvent, and sequentially eluting glycerides in pure acetonitrile, glycerophospholipids in 6% ammonia-94% acetonitrile (v/v) and glycolipids/sphingolipids in 5% formic acid-95% methanol (v/v) by LMJSS probe from TiO2 slide. Each eluate from TiO2 slide was directly delivered by LMJSS to MS for analysis. The total detection time with three desorption steps would be controlled in 3 min. The method performance for each lipid class was evaluated using lipid standards, including matrix effects (107-128%), RSDs (0.4-16%), linearity (0.98-0.99), detection limits (5-3000 ng/mL), the adsorption equilibrium constants (102-104) and adsorption capacity (1-38 µg/mm2) of TiO2 coated slides to lipids. Finally, the TiO2-based-LMJSS-MS method was applied to lipidomic analysis for blood plasma and brain tissue, and compared with direct infusion MS. Results showed that (2-5)-fold more sphingolipids/glycolipids and 40-50 more glycerophospholipids/glycerides were identified in both plasma and brain extract by the new method comparing with direct infusion MS method. Detected lipids were quantified with standard addition calibration method, and the absolute quantitation results measured by TiO2-based-LMJSS-MS were verified with that by the traditional LC-MS method (correlation coefficient >0.98, slope of correlation line = 0.87-1.05).

Production and investigation of the physico-chemical properties of MEL-A from glycerol and coconut water.

This work reports the production of MEL-A using coconut water as the carbon source. Proximate analysis of coconut water indicated the presence of nutrients necessary for growth of the organism and production of desired metabolite. The amount of MEL produced using coconut water was 3.85 g/L (± 0.35) with 74% of it being MEL-A when compared to 2.58 g/L (± 0.15) with 60% being MEL-A using glycerol, a conventional carbon source. MEL-A from coconut water consisted of 38.1% long-chain saturated fatty acids (C16:0 and C18:0) whereas with glycerol it was 9.6%. The critical micellar concentration of the biosurfactant from coconut water was 2.32 ± 0.21 µM when compared to 4.41 ± 0.25 µM from glycerol. The stability of O/W emulsion was reduced by 50% and 90% after incubation for 8 h in the case of MEL-A from coconut water and glycerol respectively when compared to synthetic surfactant, Tween-20. MEL-A from both the sources exhibited free radical scavenging activity (DPPH assay) in a dose-dependent manner wherein MEL-A from coconut water showed two fold higher activity than the other. The interaction of coconut water MEL-A with DPPC for drug encapsulation applications was also studied. The DSC measurements showed the differences in the interaction of drugs with DPPC/MEL-A liposome. The differences were also observed in the solubility of drugs after encapsulation with DPPC/MEL-A liposome.

Asymmetric Total Synthesis of Mycobacterial Diacyl Trehaloses Demonstrates a Role for Lipid Structure in Immunogenicity.

The first asymmetric total synthesis of three structures proposed for mycobacterial diacyl trehaloses, DAT1, DAT2, and DAT3 is reported. The presence of two of these glycolipids, DAT1 and DAT3, within different strains of pathogenic M. tuberculosis was confirmed, and it was shown that their abundance varies significantly. In mass spectrometry, synthetic DAT2 possessed almost identical fragmentation patterns to presumptive DAT2 from Mycobacterium tuberculosis H37Rv, but did not coelute by HPLC, raising questions as the precise relationship of the synthetic and natural materials. The synthetic DATs were examined as agonists for signaling by the C-type lectin, Mincle. The small differences in the chemical structure of the lipidic parts of DAT1, DAT2, and DAT3 led to drastic differences of Mincle binding and activation, with DAT3 showing similar potency as the known Mincle agonist trehalose dimycolate (TDM). In the future, DAT3 could serve as basis for the design of vaccine adjuvants with simplified chemical structure.

Selective enrichment of milk fat globules using functionalized polyvinylidene fluoride membrane.

We report on the development of a functionalized membrane-based technology for selective enrichment of milk fat globules from raw bovine milk. Functionalization was conducted by in situ polymerization of acrylic acid within a polyvinylidene fluoride membrane, followed by the electrostatic attachment of a cationic polymer to impart a net positive charge. The functionalized membrane-based technology enabled a one-step method of selective separation of globules directly from milk-based on size and charge. The presence of globules in the eluate was confirmed by fluorescence microscopy. Quantification of the extracted phospholipids from globules in the eluant revealed a significantly higher amount of polar lipids than the permeate. Our study describes a comprehensive analysis of selective enrichment of fat globules using a functionalized membrane and demonstrates the beneficial effect of extracted phospholipids from enriched fat globules.

Diagnostic strategy for females suspected of Fabry disease.

A total of 11 948 females suspicious of Fabry disease were tested by a combined biochemical and genetic approach. The enzyme activity, together with the concentration of lyso-GL-3 (lyso-Gb3) biomarker in dried blood spots (DBS), substantially improved the diagnostic detection of Fabry disease in females compared to the enzyme activity alone. Abnormal values for both were highly suspicious of Fabry disease (97% positive predictive value [PPV], similar to PPV in males). In cases with one abnormal biochemical value, elevated lyso-GL-3 is a far more important indicator than low enzyme activity (39% PPV vs 6% PPV). Cases with clearly negative results for both biochemical parameters are unlikely to have Fabry disease, even in clinically highly suspicious cases.

Antibacterial Activity of Sophorolipids from Candida bombicola Against Human Pathogens

Abstract Sophorolipids are glycolipids that have natural antimicrobial properties and present great potential in the pharmaceutical field. The present study aimed to produce sophorolipids from Candida bombicola using a chicken fat-based medium and evaluate the antimicrobial activity against Gram-negative (Proteus mirabilis, Escherichia coli, Salmonella enterica subsp. enterica) and Gram-positive bacteria (Enterococcus faecium, Staphylococcus aureus and Streptococcus mutans). The production of sophorolipids reached 27.86 g L-1. Based on the structural characterization, 73.55% of the sophorolipids present a mixture of acidic monoacetylated C18:2 and lactonic diacetylated C16:0, and 26.45% were present in the diacetylated C18:1 lactonic form. Bacteria submitted to sophorolipid exposure showed a reduction in viability at doses of 500 μg mL-1 and 2,000 μg mL-1 against Gram-positive and Gram-negative bacteria, respectively. These results suggest that sophorolipids produced in chicken fat medium may be used as antimicrobial agents to prevent or eliminate contamination by different pathogens.

Characterization of a New Rhamnolipid Biosurfactant Complex from Pseudomonas Isolate DYNA270.

The chemical and physical properties of extracellular rhamnolipid synthesized by a nonfluorescent Pseudomonas species soil isolate, identified as DYNA270, is described, along with characteristics of rhamnolipid production under varying growth conditions and substrates. The biosurfactant is determined to be an anionic, extracellular glycolipid consisting of two major components, the rhamnopyranoside ß-1-3-hydroxydecanoyl-3-hydroxydecanoic acid (GU-6) and rhamnopyranosyl ß→ß2-rhamnopyranoside-ß1-3-hydroxydecanoyl-3-hydroxydecanoic acid (GL-2), of molecular weight 504 and 649 daltons, respectively. These glycolipids are produced in a stoichiometric ratio of 1:3, respectively. The purified rhamnolipid mixture exhibits a critical micelle concentration of 20 mg/L, minimum surface (air/water interface) tension of 22 mN/m, and minimum interfacial tension values of 0.005 mN/m (against hexane). The pH optimum, critical micelle concentration, and effective alkane carbon number were established for Pseudomonas species DYNA270 and compared to those of rhamnolipid produced by Pseudomonas aeruginosa PG201. Significant differences are documented in the physical properties of extracellular rhamnolipids derived from these two microorganisms. The surface properties of this rhamnolipid are unique in that ultra-low surface and interfacial tension values are present in both purified rhamnolipid and culture broth containing the rhamnolipid complex (GU6 and GL2). We are not aware of prior studies reporting surface activity values this low for rhamnolipids. An exception is noted for an extracellular trehalose glycolipid produced by Rhodococcus species H13-A, which measured 0.00005 mN/m in the presence of the co-agent pentanol (Singer et al. 1990). Similar CMC values of 20 mg/L have been reported for rhamnolipids, a few being recorded as 5-10 mg/L for Pseudomonas species DSM2874 (Lang et al. 1984).

Dirhamnolipid Produced by the Pathogenic Fungus Colletotrichum gloeosporioides BWH-1 and Its Herbicidal Activity.

Fungal phytotoxins used as ecofriendly bioherbicides are becoming efficient alternatives to chemical herbicides for sustainable weed management. Previous study found that cultures of the pathogenic fungus Colletotrichum gloeosporioides BWH-1 showed phytotoxic activity. This study further isolated the major phytotoxin from cultures of the strain BWH-1 using bioactivity-guided isolation, by puncturing its host plant for an activity test and analyzing on the HPLC-DAD-3D mode for a purity check. Then, the active and pure phytotoxin was characterized as a dirhamnolipid (Rha-Rha-C10-C10) using the NMR, ESIMS, IR and UV methods. The herbicidal activity of dirhamnolipid was evaluated by the inhibition rate on the primary root length and the fresh plant weight of nine test plants, and the synergistic effect when combining with commercial herbicides. Dirhamnolipid exhibited broad herbicidal activity against eight weed species with IC50 values ranging from 28.91 to 217.71 mg L-1 and no toxicity on Oryza sativa, and the herbicidal activity could be synergistically improved combining dirhamnolipid with commercial herbicides. Thus, dirhamnolipid that originated from C. gloeosporioides BWH-1 displayed the potential to be used as a bioherbicide alone, or as an adjuvant added into commercial herbicides, leading to a decrease in herbicides concentration and increased control efficiency.

Recovery of milk fat globule membrane (MFGM) from buttermilk: effect of Ca-binding salts.

In this Research Communication we present a study of the effect of Ca-binding salts on the recovery of milk fat globule membrane (MFGM) from buttermilk. Sodium phosphate buffer was used for the purpose of MFGM recovery from buttermilk for the first time and we showed that 0.1 M buffer at pH 7.2 was the most effective for the recovery of MFGM. The fact of high efficacy of sodium phosphate buffer in recovery of MFGM from buttermilk allowed us to suggest that MFGM in buttermilk is present in association with casein through Ca- bridges formed between phospholipids of MFGM and phosphate groups of casein, primarily with k-casein as the peripheral protein of casein micelles.

Rice based distillers dried grains with solubles as a low cost substrate for the production of a novel rhamnolipid biosurfactant having anti-biofilm activity against Candida tropicalis.

In this study, rhamnolipid (RL) production by Pseudomonas aeruginosa SS14 utilizing rice based Distillers Dried Grains with Solubles (rDDGS) as the sole carbon source was evaluated and the production parameters were optimized using response surface methodology. Highest RL (RL-rDDGS) yield was 14.87 g/L in a culture medium containing 12% (w/v) rDDGS and 11% (v/v) inoculum concentration after 48 h of fermentation at 35 °C. RL-rDDGS was produced as a mixture of mono and di-RL congeners with four novel homologues Rha-C18:2, Rha-C19, Rha-C9, and Rha-Rha-C19. The RL reduced the surface tension of water to 34.8 mN/m at a critical micelle concentration (CMC) value of 100 mg/L, exhibited high stability at a wide range of pH (6-12), heating time (0-120 min), and salinity (2-12% NaCl). Furthermore, RL-rDDGS demonstrated appreciable biofilm disruptive property against Candida tropicalis. This is the first report on the usage of rDDGS for sustainable and low cost production of RL.

The outer membrane glycolipids of bacteria from cold environments: isolation, characterization, and biological activity.

Lipopolysaccharides (LPSs) are the main components of the external leaflet of the outer membrane of Gram-negative bacteria. Microorganisms that colonize permanently or transiently cold habitats have evolved an array of structural adaptations, some of which involve components of bacterial membranes. These adaptations assure the perfect functionality of the membrane even at freezing or sub-freezing growth temperatures. This review summarizes the state-of-the-art information concerning the structural features of the LPSs produced by cold-adapted bacteria. The LPS structure has recently been elucidated from species mainly belonging to Gammaproteobacteria and Flavobacteriaceae. Although the reported structural heterogeneity may arise from the phylogenetic diversity of the analyzed source strains, some generalized trends can be deduced. For instance, it is clear that only a small portion of LPSs displays the O-chain. In addition, the biological activity of the lipid A portion from several cold-adapted strains is reported.