BACKGROUND AND OBJECTIVES Azo dyes used in textile, pharmaceutical, and food industries have emerged as a major environmental hazard due to their toxic and carcinogenic properties. Conventional wastewater treatment methods are often insufficient in effectively removing these recalcitrant compounds, leading to their discharge into water bodies, resulting in severe ecological and health issues. As a promising alternative, microbial degradation has gained significant attention as an eco-friendly approach for the efficient removal of azo dyes from contaminated sewage. Isolation and investigation of microorganisms which are able to remediate food industry azo dyes were the aims of the current study. MATERIALS AND METHODS To isolate the microbial consortium able to decolorize azo dyes, samples were collected from the activated sludge in a food industrial wastewater treatment system. The edible azo dyes consisted of tartrazine, sunset yellow, and carmosin. The collected samples were inoculated into 100 ml of R2A medium containing 50 mg L-1 of individual dyes, and were then incubated at 28 °C for 7 days. Microbial decolorization was monitored using a spectrophotometer. RESULTS AND DISCUSSION Results demonstrated that the microbial consortium were able to decolorize the dyes for approximately 60% after 24 hours. The sunset yellow and carmosin dyes were decolorized more than 90% after 48 and 72 hours, respectively. Furthermore, tartrazine was decolorized more than 40% after 72-96 hours. These results revealed that the microbial consortium was able to decolorize food azo dyes and can be applied in industrial wastewater treatment plants. CONCLUSION These results revealed that the use of a microbial consortium with the capacity to decolorize azo dyes is an encouraging approach towards sustainable wastewater treatment system. This microbial consortium exhibits promising capabilities to decolorize azo dyes. These findings enhance our understanding of microbial decolorization processes and offer new prospects for addressing the growing concerns of azo dye pollution.
