Isolation, identification, and characterization of Bacillus subtilis SMP-2 from panitenga and exploring its potential for biosurfactant production

A traditional Assamese fermented food, Panitenga, was explored for potential probiotic isolation. A potent bacterial strain exhibiting biosurfactant production ability was isolated, characterized, and identified as Bacillus subtilis SMP-2. Environmental parameters were optimized for maximum cell growth and biosurfactant production that was found to be pH 6, 30°C, 130 rpm, with glycerol as the carbon (C) source, yeast extract as the nitrogen (N) source, and a C/N ratio of 3:1. At these optimized conditions, the strain yielded 8.13 ± 0.9 g/L of lipopeptide biosurfactant. This biosurfactant remarkably reduced the surface tension of water from 72 mN/m to 37 ± 0.36 mN/m, possessed a low critical micelle concentration (CMC) of 125 mg/L, and exhibited antimicrobial properties. It persisted to be stable across a wide range of physical conditions, including variations in pH, temperature, and salinity. The significantly high production yield and noteworthy properties of the biosurfactant from Bacillus subtilis SMP-2 make it a promising candidate for applications in microbial-enhanced oil recovery (MEOR), bioremediation of oil spills, production of cosmetics and pharmaceuticals, contributing to economic growth and sustainable development.