Biosurfactant production by a crude oil‐utilizing bacterium towards petroleum hydrocarbon biodegradation applications

Biosurfactants produced by microorganisms are green amphiphilic biomolecules. They have numerous advantages compared to chemical surfactants including a lower toxicity, better environmental compatibility and effective and stable properties under extreme conditions such as a wide range of temperature, pH and salinity. A highly bio‐surfactant‐producing strain of Bacillus, VTVK15 was selected among the Bacillus isolates from marine environment and oil contaminated sites in Ba Ria—Vung Tau. Sequence analysis of 16S rDNA showed that the VTVK15 strain was 99% similar with 16s rDNA sequence of Bacillus megaterium. The suitable conditions for the bio‐surfactant production by the strain VTVK15 were 37 °C, pH 7; 2% w/v and 0.4% w/v for temperature, initial solution pH, concentration of carbon substrate (crude oil), and concentration of nitrogen substrate ((NH4)2SO4), respectively. The emulsification index (E24) increased from 51.8% to 67.7% with suitable conditions. The petroleum hydrocarbon degradation (TPH) efficiency by the strain Bacillus megaterium VTVK15 in crude oil estimated using TPH analysis was 72% after 14 days. These results revealed that the strain VTVK15 exhibited a tremendous potential for bioremediation of petroleum hydrocarbon contaminants.