Evaluation and functional characterization of a biosurfactant produced by Lactobacillus plantarum CFR 2194.

The study details the investigations on the ability of Lactobacillus plantarum CFR 2194, an isolate from kanjika, a rice-based ayurvedic fermented product, to produce biosurfactant. Surfactant production, as a function of fermentation time, indicates that the maximum production occurred at 72 h under stationary conditions. Isolation, partial purification, and characterization of the biosurfactant produced have been carried out, and Fourier transform infrared spectroscopy (FTIR) spectra demonstrated that biosurfactants were constituted by protein and polysaccharide fractions, i.e., possessed the structure typical of glycoprotein, which is affected by the medium composition and the phase of growth of the biosurfactant-synthesizing strain. Critical micelle concentration (cmc) of the biosurfactant was found to be 6 g l(-1). The emulsification index (EI), emulsification activity (EA), and emulsion stability (ES) values of the biosurfactant have confirmed its emulsification property. Aqueous fractions of the produced biosurfactant exhibited a significant antimicrobial activity against the food-borne pathogenic species: Escherichia coli ATCC 31705, E. coli MTCC 108, Salmonella typhi, Yersinia enterocolitica MTCC 859, and Staphylococcus aureus F 722. More importantly, the biosurfactant from L. plantarum showed antiadhesive property against above food-borne pathogens. The results thus indicate the potential for developing strategies to prevent microbial colonization of food contact surfaces and health-care prosthesis using these biosurfactants.