Microaerobic degradation of 2-Mercaptobenzothiazole present in industrial wastewater

•The isolated strain CSMB1 utilizes benzothiazole and its derivatives as sole carbon and energy.•Benzene ring opening of benzothiazoles is through meta cleavage under microaerobic condition.•A microaerobic degradative pathway was proposed for 2-Mercaptobenzothiazole.•The strain CSMB1 is an ideal candidate for leather industrial wastewater treatment. Microaerobic degradation of 2-Mercaptobenzothiazole (2-MBT) was investigated using an isolated bacterial strain CSMB1. It was identified as Alcaligenes sp. MH146 by genomic analysis. The isolate degraded 50mg/L concentration of 2-MBT which was measured in terms of Total organic carbon (TOC) (700mg/L). A maximum degradation of 86% with a residual TOC concentration of 101mg/L was obtained after 72h, with the biomass growth of 290mg/L. The presence of specific activity of catechol 2, 3 oxygenase was observed in all the tested derivatives of benzothiazoles and the benzene ring opening was observed through meta cleavage. By analyzing the 72h incubated culture supernatant, 2-MBT, and all its biotransformed products were degraded into polar compounds. With the analytical results obtained, a possible microaerobic degradative pathway was proposed and illustrated for 2-MBT. It is concluded that microaerophilic isolate CSMB1 was able to degrade 2-MBT and its intermediates by utilizing them as sole carbon and energy.