Bacillus tropicus strain:AOA-CPS1 Genome sequencing and assembly. Bacillus tropicus strain:AOA-CPS1

Pentachlorophenol (PCP) is a recalcitrant biocide that bioaccumulates in the environment due to its persistent nature and has been listed as a priority pollutant owing to its toxicological and health effects. In this study, a novel PCP-degrading Bacillus cereus was isolated from wastewater and characterized for PCP degradation PCP in a batch reactor. Degradation kinetics were elucidated via substrate inhibition models, while PCP transformation was established by spectrophotometric and GC-MS analysis. The isolate shared 95% sequence homology with Bacillus cereus XS2 and is closely related to some B. cereus strains previously reported for the degradation of PCP and other related pollutants. The isolate degraded 74% of PCP (within 9 days at initial PCP concentration of 350 mg l-1) and other congeners in batch culture of, both singly and in co-metabolism. The degradation followed first and zero-order kinetics at low and high PCP concentration, respectively with biokinetic constants: maximum degradation rate (0.0996 mg l-1 h-1); substrate inhibition constant (723.75 mg l-1); half-saturation constant (171.198 mg l-1) and R2 (0.98), suggesting the possibility of using this isolate for bulk degradation of PCP. PCP-degrading genes (cpsABCDE) and cytochrome p450 were amplified from the genome of the organism. Two different PCP degradation pathways were proposed based on the identified metabolites and genes amplified. Cloning and expression of the catabolic genes are underway to map out the concise pathway for PCP transformation by this isolate.