Purification and characterization of dehalogenase from Bacillus cereus SN1 isolated from cow dung

Aims: This study was aimed to characterize a dehalogenase derived from Bacillus cereus SN1 isolated from cow dung. Methodology and results: Cell-free extract of Bacillus cereus SN1 was purified using ion exchange and gel filtration chromatography. Fraction B2 of gel filtration gave the highest enzyme specific activity (0.155 μmol CI/min/mg). The results of SDS-PAGE showed the enzyme was 25 kDa in size. The enzyme reached its optimum activity at 30 °C at pH 6, and was inhibited by Mercury(II) sulfate (HgSO4). The Km and kcat values were 0.2 mM and 1.22/sec, respectively. The partial dehalogenase gene sequence was amplified using Group I dehalogenase primers. The amplified gene sequence was designated as DehSN1. Conclusion, significance and impact of study: Dehalogenase from Bacillus cereus strain SN1 revealed new characteristics of dehalogenase protein. The findings indicated that the DehSN1 dehalogenase is a promising candidate for further studies as a bioremediation agent for agricultural applications.