Functional group characterization of lactic bacterial biosurfactants and evaluation of antagonistic actions against clinical isolates of methicillin‐resistant Staphylococcus aureus

Abstract

The present study investigated the antimicrobial and antibiofilm potential of biosurfactants derived from Lactobacillus fermentum Lf1, L. fermentum LbS4 and Lactobacillus plantarum A5 against clinical isolates of methicillin‐resistant Staphylococcus aureus (MRSA). The cell wall‐bound and intracellular biosurfactants were extracted by solvent extraction method. Fourier‐transform infrared spectroscopy‐based characterization of biosurfactants revealed the heterogeneous chemical composition involving proteins, fatty acids and carbohydrate moieties in LbS4 and A5, while only the sugar and lipid fractions in Lf1. Fatty acid profiling using Gas chromatography‐mass spectrometry indicated hexadecanoic acid and stearic acid as the predominant fatty acids in the biosurfactants of all these strains. Biosurfactants demonstrated dose‐dependent antibacterial action against MRSA isolates with the highest inhibition zone diameter (30·0 ± 0·0 to 35·0 ± 0·0 mm) recorded at 400 mg ml−1. Biosurfactants showed an excellent staphylococcal antibiofilm activity by preventing the biofilm formation and disrupting the preformed biofilms. Visual inspection through scanning electron microscopy witnessed the biosurfactants‐induced alteration in the cell membrane integrity and subsequent membrane pore formation on staphylococcal cells. Taken together, our findings emphasize the prospects of biomedical applications of biosurfactants as bactericidal and biofilm controlling agents to confront staphylococcal nosocomial infections.

Two novel lactic acid bacteria, Limosilactobacillus fermentum MN-LF23 and Lactobacillus gasseri MN-LG80, inhibited Helicobacter pylori infection in C57BL/6 mice

“…27 The bacteriostatic effect of the fermentation supernatant of LAB mainly comes from the lactic acid and SCFA such as acetate, propionate, and butyrate, creating an unfavorable acidic environment for invading pathogens. 28 L. fermentum and L. gasseri can release anti-microbial agents such as bacteriocins, 29,30 biosurfactant 31,32 and hydrogen peroxide. 33,34 In line with this, our results showed that LF23 and LG80 fermentation supernatants could significantly inhibit the growth of H. pylori and reduce H. pylori infection in vivo , indicating that they can metabolize and produce bacteriostatic substances.…”

Elimination of Pathogen Biofilms via Postbiotics from Lactic Acid Bacteria: A Promising Method in Food and Biomedicine

“…BS is a compound that exhibits amphiphilic properties and is produced by a variety of microorganisms [89]. It is classified as a secondary metabolite of microorganisms and encompasses a range of structural groups, such as glycolipids, polysaccharide-lipid complexes, lipoprotein-lipopeptides, and phospholipids.…”

ESKAPEE Pathogen Biofilm Control on Surfaces with Probiotic Lactobacillaceae and Bacillus species

“…Among Lactobacillaceae, Lactiplantibacillus plantarum was the most frequently reported species, with 36 instances of growth inhibiting, bactericidal, or anti-biofilm properties against at least one ESKAPEE pathogen . Lactobacillus fermentum [21,22,28,30,31,43,[55][56][57][58][59][60][61][62][63][64][65] and Lacticaseibacillus rhamnosus [19,21,25,27,31,[66][67][68][69][70][71][72][73][74][75][76][77] were both reported 17 times, Lactobacillus acidophilus was reported 16 times [21,28,55,67,[78][79][80][81][82][83][84][85][86][87][88]…”