Differential catalytic action of Brevibacillus laterosporus on two dissimilar azo dyes Remazol red and Rubine GFL

Abstract

This comparative study disclosed the diverse catalytic activities of Brevibacillus laterosporus on two different azo dyes. It decolorized 100% of Remazol red and 95% of Rubine GFL within 30 and 48 h respectively, under static condition at 50 mg l⁻¹ dye concentration. Significant increase was observed in azo reductase, NADH-DCIP reductase, veratryl alcohol oxidase and tyrosinase in cells obtained after decolorization of Remazol red; whereas these values were much different with complete inhibition of azo reductase during decolorization of Rubine GFL. The plausible pathway of dye degradation obtained from Gas chromatography-Mass spectroscopy (GC-MS) data confirmed the different metabolic fate of these structurally unidentical dyes. FTIR and HPTLC analysis of extracted metabolites confirmed the biodegradation, while phytotoxicity study assured the detoxification of both the dyes studied. The results obtained in this study suggests, i) sulpho and hydroxyl group present at ortho position to azo group stimulated reduction of azo bond by azo reductase in Remazol red, ii) the same reduction was totally hampered due to presence of ethyl-amino propanenitrile group at para position to azo group in Rubine GFL.

Synergistic effect of biological and advanced oxidation process treatment in the biodegradation of Remazol yellow RR dye

“…Tyrosinase activity was calculated in a reaction mixture of 2 mL, containing in 0.1 M phosphate buffer (pH 7.4) with 0.01% catechol at 495 nm 24 . Azoreductase assay was carried out using Methyl red as substrate as reported by Kurade et al 33 .…”

Combined biological and advanced oxidation process for decolorization of textile dyes

“…Tyrosinase activity was calculated in a reaction mixture of 2 mL, containing in 0.1 M phosphate buffer (pH 7.4) with 0.01% catechol at 495 nm [56]. Azoreductase assay was carried out using Methyl red as substrate as reported by Kurade et al [27]. Riboflavin reductase activity was determined using riboflavin as substrate as mentioned in previously reported method [41].…”

Purification and characterization of extracellular laccase produced byCeriporiopsis subvermisporaand decolorization of triphenylmethane dyes

“…The laccase potential of synthetic dye decolorization is determined by the structure of produced enzymes, and their specificity and activity . Although some bacterial laccases can be used for synthetic dye degradation , laccases produced by white‐rot fungi have the higher redox potential and they are able to degrade resistant dyes . The structure of substrate is a key factor in dye decolorization.…”