Pseudomonas sp. JH007에 의한 DL-2-Chloropropionic Acid로부터 D-Lactic Acid의 생산

For the production of D-lactic acid from DL-2-chloropropionic acid, about 80 strains of bacteria capable of assimilating DL-2-chloropropionic acid as a sole carbon and energy source were isolated from the soil. JH-007 strain that showed the higest productivity of D-lactic acid and didn't produce L-lactic acid from DL-2-chloropropionic acid was selected from them and identified as Pseudomonas sp. The optimal conditions for the production of D-lactic acid from DL-2-chloropropionic acid were examined. The resting cells of JH-007 cultured in LB medium containing 3 g/l of DL-2-chloropropionic acid were used as an enzyme source. The reaction mixtures for the maximal production of D-lactic acid were consist of 10 g/l of resting cells and 3 g/l of DL-2-chloropropionic acid in 125 mM sodium carbonate buffer. The optimal pH for the reaction was 10.0 and the optimal temperature was 30$\circ$C. When 1 g/l of DL-2-chloropropionic acid was added intermittently to the reaction mixture under the above condition, 5.72 g/l of D-lactic acid was produced after incubation of 5 hrs. This amount of D-lactic acid corresponded to a 98.4% yields and the optical purity was 99.8%.