In the present study, the decolorization and
degradation of azo dye Direct Orange 16 (DO-16) by a
potential bacterial isolate isolated from textile effluent were
evaluated. Through 16S rRNA sequence matching, the
potential isolate was identified as
Micrococcus luteus
strain
SSN2. The effects of various factors (pH, temperature, salt
and dye concentration) on decolorization were investigated.
The strain SSN2 had the ability to decolorize DO-16 with
96 %efficiency at pH 8, 37 °C and 3 % NaCl in a short time
of 6 h under static conditions. DO-16 decolorization was
assessed by UV–Vis spectrophotometer with gradual
decrease of dye peak intensity at 430 nm (λmax). Analytical
techniques (thin-layer chromatography, Fourier transform
infrared spectroscopy and high-performance liquid chromatography)
further confirmed that biodegradation of DO-
16 was due to reduction of the azo bond. The phytotoxicity
assay (with respect to seeds of
Vigna mungo
and
Vigna
radiata
) demonstrated the less toxic nature of the DO-16-
degraded products compared to the toxic azo dye.
