Enhancement of solubilization and biodegradation of diesel oil by biosurfactant from Bacillus amyloliquefaciens An6

The strain Bacillus amyloliquefaciens An6 was found to be a potent producer of biosurfactant when cultivated Landy medium. The produced biosurfactant showed high physicochemical properties in terms of the surface activities. It was able to reduce surface tension to less than 30 from 72 mN/m and its critical micelle concentration (CMC) is 100 mg/L. The emulsifier produced was found to be an alternative to chemically synthesized surfactants since it shows high solubilization efficiency towards diesel oil (71.54% at 1 g/L), better than SDS and Tween 80. Further, it showed good stability over a wide range of pH, temperature and salinity. It was found that it can enhance the diesel oil degradation efficiency of the An6 strain. Moreover, it was found that it can solubilize diesel more effectively than SDS and Tween 80 and therefore has potential applications in bioremediation. •B. amyloliquefaciens An6 was an efficient degrader of diesel oil.•An6 was potential source for biosurfactant production.•Biosurfactant An6 reduced surface tension and it exhibited a high emulsifying activity.•Biosurfactant An6 was effective over wide range of temperature, pH and salinity.•Biosurfactant An6 shows high solubilization efficiency towards diesel oil.