Decolorization of Methyl Orange (As a Model Azo Dye) by the Newly Discovered Bacillus Sp

Abstract

A bacterial strain (strain PS) was isolated from the textile effluents carrying Serilene Black BNFS® (C.I. Disp. Blk. Mix) disperse dye. The isolate was able to decolorize the dye without the need for any exogenous carbon source. Full sequencing of its 16S rRNA indicated that Bacillus sp strain PS is related to Bacillus cereus groups. Silica- gel-thin layer chromatography of Serilene black dye showed that its main component is a blue dye. FT- IR analysis of this blue fraction showed that its structure corresponds to azoic dyes. Thus Bacillus sp, strain PS was used to decolorize methyl orange as a model azo dye, which it did after 2 days of incubation under aerobic conditions on a shaker incubator (30°C, 140 rpm). Comparing TLC and GC-MS analyses with the authentic sample main showed that its decomposition product is N, N-dimethyl 1, 4- phenylene diamine. Experiments with N, N-dimethyl 1, 4-phenylene diamine as a co-substrate in mineral medium showed that this component disappeared after 7 day incubation. These observations confirm that the decomposition of Serilene dye occurs in a manner similar to that of methyl orange.

Keywords

• azo dye
• bacillus
• decolorization
• methyl orange
• textile effluent