Enzyme based cleavage strategy of Bacillus lentus BI377 in response to metabolism of azoic recalcitrant

► Elucidation on enzyme dependant color removal strategy by Bacillus lentus BI377. ► Decolorization of diazo Reactive Red 141 was foremost than monoazo Reactive Red 2. ► Azoreductase cleaves azo bond in diazo RR141 whereas peroxidase mediated in RR2. ► Intermediate metabolites of RR2 and RR141 lead to mineralization via TCA cycle. Bacillus lentus BI377 (B. lentus BI377) an alkaliphilic strain has accomplished the discriminate color removal strategy for Reactive Red sulfonated azoic recalcitrant irrespective of their molecular structure. During the decolorization experiment, it was observed that the diazo dye first followed chromophoric cleavage by azoreductase via typical azoreduction whereas, in case of monoazo dye, cleavage took place by peroxidase via successive electron transfers to oxide surface resulting in the asymmetric cleavage of the azo bond. Dismutation of oxidative stress by reactive metabolites has confirmed by superoxide dismutase activity. Carbon monoxide (CO) binding spectra, the content of cytochrome P450 and spectroscopy analysis by GCMS, FTIR and 1H NMR of intermediate metabolites indicated the differentiate pattern of diazo and monoazo dye decolorization fuse to central metabolic pathway. Declined percentage of TOC and the cytotoxicity (MTT) study confirmed that environmentally benign intermediates may lead to mineralization.