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 degrees 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. Graphical illustration of biosurfactant produced from a crude oil utilizing-bacterium (isolated from oilfield, Vung Tau, Vietnam) and application of bioremediation for petroleum hydrocarbon contaminated environments. image