/+//Biodecolorization of Reactive Black5 and Reactive Red120 azo dyes using bacterial strains isolated from dairy effluents

In a biological treatment of an industrial effluent, the indigenous bacteria have already been used. In this study, the three bacteria strains which are potent in the decolorization of azo dyes were isolated from dairy effluent and used for decolorization of Reactive Black5 and Reactive Red120 azo dyes and decolorization test of each dye was conducted at five concentration levels (10, 50, 100, 150, and 200 mg/l). The pH of which was adjusted to 7 and incubated at 37 °C for 3 days. The strains were identified as Staphylococcus sp. and Micrococcus luteus strains by 16S rRNA gene sequences analysis. The strains were deposited in GenBank with accession numbers of KX180131, KX180132, and KX180133 and submitted to laboratory identifier named Staphylococcus sp. MEH038S, Micrococcus luteus strain SEH038S, and Micrococcus luteus strain FEH038S. Three days into incubation, the lowest efficiency was at a concentration level of 200 mg/l for each dye. Decolorization efficiencies for Staphylococcus sp. MEH038S, Micrococcus luteus strain SEH038S, and Micrococcus luteus strain FEH038S at the concentration level of 200 mg/l for Reactive Red120 were 89.7, 87.1, and 89.3, and for Reactive Black5 were 90.8, 90.0, and 89.9, respectively. Based upon this study, dairy effluents can be used as a suitable alternative to the decolorization of textile wastewater. This study demonstrates a report on grounds of elucidation for the use of non-indigenous bacteria in the treatment of industrial wastewater. © 2018, Islamic Azad University (IAU)