Melanodins are amino-carbonyl complex, predominantly present in sugarcane molasses based distillery wastewater as major source of colourant. The indiscriminate discharge of post methanated distillery effluent (PMDE) from distilleries is a major source of soil and water pollution which directly or indirectly affects the animals and human beings. Adequate treatment is therefore imperative before the effluent is discharged. The effect of pH on melanoidin extraction from PMDE and its decolorization by a developed potential consortium of Proteus mirabilis (IITRM5; FJ581028), Bacillus sp. (IITRM7; FJ581030), Raoultella planticola (IITRM15; GU329705) and Enterobacter sakazakii (IITRM16, FJ581031) was studied. Melanoidin was extracted with isopropanol at different pH. The most effective pH for melanoidin extraction was noted at pH 11.0 (2.87%, w/v) from PMDE of color range 80000-85000 Co-Pt with high BOD (29120±10.00 mg/l) and COD (58018.33±23.63 mg/l). Subsequently, the maximum de-colorization (70.00%) of PMDE was noted in the presence of glucose (1%, w/v), peptone (0.05%) at pH 7.0 and minimum at pH 11.0 (11.66%, w/v) within 168 h bacterial incubation. Further, the results also revealed that the pH directly affected melanoidin extraction and bacterial de-colorization of PMDE. The cultures of these strains have better color removal ability after melanoidin extraction and thus can be utilized for bioremediation of PMDE affected sites.
