Isolation and characterization of bacillus amyloliquefaciens 6A: A novel kerosene oil degrading bacterium

Abstract

Abstract Bacillus amyloliquefaciens 6A, isolated from kerosene contaminated industrial wastewater, could remove 13, 39, 40 and 64% kerosene oil as compared to the microorganisms indigenously present in the industrial effluent which could degrade only 14, 16, 27 and 28% kerosene oil after 2, 4, 6 and 8 days, respectively. Kerosene biodegradation behavior was evaluated by studying biodegradation kinetics, half-life and thermodynamics to determine the suitability of the process. Kerosene biodegradation process followed pseudo first order kinetics and found greatly influenced with temperature. Moreover, extracellular lipase activity was calculated and relationship between concentration of kerosene oil and enzyme activity (oil degradation) was established by Michaelis–Menten plot. The enzyme followed the single substrate Michaelis–Menten kinetics with Vmax (maximum rate) 9.251 ( μ g/ml)/min and Km (Michaelis constant, substrate affinity) 8.325 μ g/ml for kerosene oil. Furthermore, kerosene hydrocarbon fractions before and after bacterial treatment were estimated by GC–MS and TLC which revealed the degradation of many aliphatic and aromatic hydrocarbon constituents of kerosene. It is the first Gram positive bacterium reported from Pakistan which can transform long chained hydrocarbons (C11–C34) into small metabolites. In conclusion, bacterial strain has proved cost-effective, proficient and a very expedient tool in green chemistry to decontaminate environmental hydrocarbon pollutants.