Isolated bacterial strain of Achromobacter sp. MTCC 5605 and a highly enantioselective epoxide hydrolase isolated therefrom

A process for the purification of epoxide hydrolase from the bacterial strain of Achromobacter sp MTCC 5605 isolated from petroleum contaminated sludge sample comprising the steps of:

• [a] isolating said bacterial strains by transferring 1.0 g of the sludge sample in 100 ml of enrichment medium comprising mineral salts medium with an epoxide as sole carbon source and incubating at 35° to 40° C. for one week to form an isolate after which the isolates was purified 2-3 times on nutrient agar plates;
• [b] checking the purified isolates as obtained in step [a] for enantioselectivity and growth on a fermentation medium for enzyme enrichment;
• [c] selecting the strain Achromobacter sp. MTCC 5605 as the best producer of enantioselective epoxide hydrolase;
• [d] purifying the epoxide hydrolase from Achromobacter sp. MTCC 5605 selected in step [c] after growing the strain in a fermentation medium with epoxide as the sole carbon source, followed by homogenization to form a homogenate;
• [e] centrifuging the homogenate of step [d] at pH 7.0 to form a pellet and resuspending the pellet in Tris-HCl buffer of pH 8.5 to form a suspension, and;
• [f] centrifuging the suspension of step [e] to obtain the supernatant having the desired enantioselective epoxide hydrolase, followed by desalting concentrating and separation using a centrifugal concentrators to further purify the epoxide hydrolase.