First Report of using Response Surface Methodology for the Biodegradation of Single Azo Disperse Dyes by Indigenous Daedalea dickinsii-IEBL-2

Textile dyes accounts for 22 % of total dyes utilization and are potential pollutants due to their toxicity and carcinogenicity. Brown Rot Fungi (BRF) have great potential of biodegradation of dyestuffs due to their efficient nonspecific ligninolytic enzyme system. Current study was conducted for application of indigenous Daedalea dickinsii IEBL-2, a brown rot fungi, to degrade single azo disperse dyes i.e. disperse violet-63 and disperse orange-30. Response Surface Methodology (RSM) with Box Behnken Design was employed to optimized biodegradation process. Ligninolytic enzymes involved in biodegradation were also studied and biodegradation process was monitored by High Performance Liquid Chromatography (HPLC). There was 72.141.1% and 68.711.04% biodegradation observed after screening experiments for dye-1 and dye-2. Optimization by RSM at step-1 increases biodegradation to 80.831.35% and 78.31.16% and after step -2, 88.931.32% and 93.321.54% respectively. Study of ligninolytic enzymes i.e manganese peroxidase, lignin peroxidase and laccase revealed their involvement in biodegradation process. HPLC analysis confirmed the biodegradation process and conversion of complex dyes into simple secondary amines i.e diphenylamine and 3-methyldiphenylamine. These findings would help to reduce the environmental pollution by textile effluent and also reduces the risk of certain diseases.