Production and Characterization of Biosurfactant from Bacillus subtilis YB7

Biosurfactants (BS) are of recent interest due to their unique properties including structural diversity, higher biodegradability, lower toxicity and exhibit stable activity at extreme conditions including pH, temperature and ionic strength. They are found to have applications in medical and environmental fields. Some of the BS are potential antimicrobial agents and are suitable alternatives to synthetic antibiotics. In this perspective, a surfactant producing microorganism has been screened and isolated from a polymer dump site, which was characterized as Bacillus subtilis YB7. This microorganism was capable of producing 0.5 g L super(-1) of crude extract (dry weight) in the mineral salt medium. The FTIR and LC/MS analysis of the crude extract showed the presence of similar functional groups and six isoforms, respectively as that of the commercially available Sigma surfactin. However, the proportions of the peaks vary from sigma surfactin. Molecular mass of the major peak in the crude extract is 1023 (M+H) super(+) which is equivalent to C sub(14) surfactin analog, whereas it is 1035 (C sub(15) surfactin) in case of sigma surfactin. The crude extract reduced the surface tension of water from 72 to 30 mN m super(-1) at the CMC of 40 M. This particular strain produced unique type of cycliclipopeptide analogs.