Biodegradation of malachite green by Kocuria rosea MTCC 1532

Malachite green (50 mg/L) was completely decolorized under static anoxic condition within 5 h by bacteria Kocuria rosea MTCC 1532; however decolorization was not observed at shaking condition. K. rosea have also shown decolorization of azo, triphenylmethane and industrial dyes (cotton blue, methyl orange, reactive blue 25, direct blue-6, reactive yellow 81, and red HE4B). Semi-synthetic media containing molasses, urea and sucrose have shown 100, 91, 81% decolorization respectively. Induction in the activities of malachite green reductase and DCIP reductase was observed during MG decolorization suggesting their involvement in the decolorization process. UV-Visible absorption spectrum, HPLC and FTIR analysis showed degradation of MG. Toxicity study revealed the degradation of MG into non-toxic products by K. rosea.