Isolation Characterization and Optimization of Malachite Green Dye Degrading Bacteria Isolated from Textile Industry Effluent

Abstract

newlineMalachite Green, a dye from the triphenylmethane group, is widely used in the textile industry and is released into the environment through textile wastewater. Due to its toxicity, mutagenicity, and carcinogenicity, malachite green is a frequent environmental hazard that poses a serious hazard to non-target creatures, including people. Water contamination brought on by the textile industries is a serious problem on a global scale. The objective of this study was to identify and characterize possible microorganisms from textile effluents that could degrade Malachite Green (MG) color. This study investigated the application of mixed biofilms formed by two Pseudomonas strains (NAA22 and NAA23) for bio- decolorization of malachite green (MG) dye. The isolated strains displayed biofilm formation and MG decolorization capabilities. Mixed biofilms exhibited significantly greater biofilm formation and MG decolorization (94.3%) compared to individual strains, suggesting synergistic interactions. This decolorization efficiency surpassed previously reported values for single strain decolorization. The mixed biofilms tolerated a broad range of temperatures (20-40°C) and pH (5- 9), with optimal decolorization at neutral or slightly acidic conditions (pH7.0). Enzyme analysis revealed laccase, NADH-DCIP reductase, and azoreductase as key contributors to MG decolorization, with significantly higher activity in mixed biofilms. Importantly, the bio- decolorization process transformed MG into non- phytotoxic compounds, demonstrated by seed germination and growth assays. These findings propose a promising and environmentally safe approach for MG bioremediation using mixed Pseudomonas biofilms.