Wastewater effluents from azo dye production and other dye-stuff using industries contain significant amounts of highly resistant azo dyes that require special treatment processes to prevent groundwater contamination. The present study is based on the approach of aerobic followed by anaerobic step for biodegradation and decolorization of azo dye. The main objective of this work was the adaptation, isolation and preparation of mixed microbial culture, from laboratory collection, catabolically able to biodegrade under aerobic conditions bordo azo dye present in mother lye after industrial production of that dye. The anaerobic step needed for biodegradation of azo dye was performed by the use of adapted active anaerobic sludge from a wastewater treatment plant of the sugar industry. The adapted aerobic and anaerobic microbial cultures demonstrated significant biodegradative enzymatic potential and can be further used for development of a continuous aerobic – anaerobic process for the treatment of wastewater from industrial production of azo dye.