Alliinase-like Enzymes in Fruiting Bodies of Lentinus edodes: Their Purification and Substrate Specificity

3-Chloro-d-alanine chloride-lyase, which occurs in the cells of Pseudomonas putida CR 1-1, catalyzes not only the α,β-elimination reaction of 3-chloro-d-alanine to form pyruvate, but also its β-replacement reaction in the presence of a high concentration of sodium hydrosulfide to form d-cysteine. Using the β-replacement reaction, the enzymatic synthesis of d-cysteine by resting cells was investigated. The culture conditions for cell production of the bacterium with high d-cysteine-producing activity and the reaction conditions for d-cysteine production were optimized. Under these optimal reaction conditions, 100% of the added 3-chloro-d-alanine could be converted to d-cysteine and, as the highest yield, 20.6 mg of d-cysteine per 1.0 ml of reaction mixture could be synthesized.