DECOLORIZATION OF DYES DIRECT RED 31 (DR 31); DIRECT BLUE 71 (DB 71) AND DIRECT BLACK 19 (DB 19) BY NEWLY ISOLATED Bacillus sp. DM1

Abstract

In this study, the decolorization potential of novel Bacillus sp. DM1 isolated from textile effluents was evaluated. Decolorization of direct red 31 dye was 89% (± 1.20); direct blue 71 dye was 90% (± 0.84) and direct black 19 dye was 81% (± 0.39) after 24 hours at 100 ppm concentration. It took 48 hours for nearly complete decolorization of red and blue dyes and 72 hours for black dye. Dextrose showed 97% (± 0.91) decolorization of blue dye, sucrose 95% (± 1.11) decolorization of black dye and lactose 98% (± 1.35) decolorization of red dye. Yeast extract showed 94% (± 0.80) and 97% (± 0.43) decolorization of black and red dye respectively, whereas sodium nitrate showed 95% (± 0.73) decolorization of blue dye. pH 7 and temperature 35 0 C was found optimum for decolorization of the dyes. 7% inoculum size for red and blue dye and 8% for black dye were optimum.