Abstract

Ng Hong Jing, Fatin Hanani Sulaiman, Roswanira Ab. Wahab, Rolando V. Pakinging Jr. , Noor Aini Abdul Rashid and Fahrul Huyop*

The bacterial isolate HJ1, which was identified as a Methylobacterium sp., grew on 2, 2-dichloropropionic acid as the sole carbon source and produced a 2-haloalkanoic acid hydrolytic dehalogenase. This non-stereospecific dehalogenase E (DehE) catalysed the hydrolytic dechlorination of 2, 2-dichloropropionic acid and D, L-2chloropropionic acid to produce pyruvate and lactate, respectively. The enzyme was purified to homogeneity and characterized. The molecular weight was 36 kDa by SDS-polyacrylamide gel electrophoresis and 72 kDa by gel filtration, suggesting that the enzyme is a protein dimer. The purified enzyme was only inhibited by HgSO4 and was non-stereospecific to haloalkanoic acids. The Km value for the hydrolysis of 2, 2- dichloropropionic acid was 0.25 mM. The enzyme removes chloride present on the -position, but not on the -position, of a number 2–carbon alkanoic acids.