DYE DEGRADATION BY Bacillus subtilis AND PCR AMPLIFICATION OF CotA GENE

The effluents from textile industries contain large amounts of dyes and chemicals containing trace metals such as Chromium (Cr), Arsenic (As), Copper (Cu) and Zinc (Zn) are capable of harming the environment and human health. They also contain other organic and microbial impurities. Effluents discharged from the textile industries are subjected to various physico-chemical treatments such as flocculation, coagulation, ozonation and biological treatment for the removal of organics, nitrogen, phosphorus and metal removal. Besides, the physico-chemical processes have many disadvantages viz, they are expensive, generate large volumes of sludge and mostly require the addition of hazardous chemical substances that may pollute the environment. As an alternative, laccases are used for the decolourisation and detoxification of dyes because they are environment friendly, cost effective and also for their ability to transform toxic compounds into safer metabolites. In the current work, the dye degrading strain Bacillus subtilis was isolated from the textile industry effluents of Ayyampettai, Kanchipuram and its dye degradation activity was studied. Then the laccase producing gene (CotA) from Bacillus subtilis, was isolated and amplified using Polymerase Chain Reaction (PCR). The size of the obtained PCR product (CotA gene) was found to be 1542 bp.