Microbial decolouration of azo dyes: A review

► Microbial decolouration of azo dyes is an efficient and ecofriendly way to treat textile wastewater. ► Combined advanced oxidation process and microbiological systems, microbial fuel cells and genetically modified microorganisms have demonstrated to improve the results dye removal. ► Microorganisms isolated from dye contaminates places were more efficient to the removal of azo dyes.