Exploring prospective forested wetland — Actinomycetes for biodeterioration of genotoxic textile azo dyes

Abstract

Disposal of synthetic textile dye effluents into waterbodies is a major cause of water pollution and undesirable toxicity on aquatic organisms affecting their metabolic and hormonal cycles. Moreover, it affects human health significantly by carcinogenic and mutagenic effects. Therefore, this study targets the biotreatment of azo dyes as a green eco-friendly tool using the tropical mangrove actinomycete, Streptomyces coelicolor strain SPR7, that manifests versatile decolourization of azo dyes. The highest decolourization rate (97.5%) was achieved using Methylene Blue (MB) within 72 h under the optimal conditions. Molecular docking analysis was accomplished by Autodock software, to discern docking score, binding pocket residues and interaction of azoreductase, DyP-type peroxidase and laccase with MB. The in vitro findings were highly correlating with in silico appraisals. UV-vis spectrometry, HPLC and FTIR were validating the MB biodecolourization and degradation. Interestingly, the strain detoxified MB viz. further validated by the Vigna radiata toxicity assay. Supplementarily, azo reductase was assessed to be the key biocatalyst for decolourization, while other two enzymes were involved in further mineralization of decolourized metabolites. Henceforth, a coupled in silico cum biological dye deterioration is a booming strategy for an economical, eco-friendly and time saving bioremediation to reuse textile wastewater.