Characterization of Crude Oil Degrading Marine Bacterium Bacillus licheniformis
摘要
The spillage of petroleum hydrocarbons, one of the most versatile energy resources, leads to disastrous environmental pollution. The present study aims to degrade oil using enzymes from bacterial strains. A total of 39 bacteria were isolated from six different soil samples collected from Ullal Beach, Mangalore, Karnataka, located at 12°52′N latitude and 74°49′E longitude, India. All 39 bacterial isolates were screened for the production of four industrially important extracellular enzymes. Among these isolates, ten showed the highest lipase production. These cultures were further screened for bio-surfactant assays, including oil displacement and drop collapse assay and Emulsification Index. EBPL0613-F2 exhibited the best reaction in crude oil degradation. A polyphasic taxonomical approach identified the crude oil-degrading bacterium EBPL0613-F2 as Bacillus licheniformis and submitted in NCBI and the Accession Number is PP059616. It was then cultivated in ocean water media with tween 20 and 1% crude oil as the sole carbon and energy source. The strain was screened for lipase quantitative and qualitative assay and the protein content was also estimated. The identified bacterial strain Bacillus licheniformis EBPL0613-F2 demonstrated moderate lipase activity, with 76 U/ml and 24 U/ml, respectively, after 48–72 h of incubation in the crude oil substrate. For Tween 20 substrates, it exhibited 36 U/ml and 34 U/ml, respectively. FTIR analysis was used to examine the properties of crude oil following the biodegradation. The results suggest that, EBPL0613-F2 recorded the highest degradation rate so this culture has the potential for use in the degradation of crude oil in a greener manner.