N-Carbamoyl-L-Cysteine as an Intermediate in the Bioconversion from D,L-2-Amino-Δ (2)-Thiazoline-4-Carboxylic Acid to L-Cysteine by Pseudomonas sp. ON-4a

We investigated the conversion of D,L-2-amino-Δ (2)-thiazoline-4-carboxylic acid (D,L-ATC) to L-cysteine with Pseudomonas sp. ON-4a, an ATC-assimilating bacterium. Cysteine and N-carbamoylcysteine (NCC), but not S-carbamoylcysteine (SCC), were produced from D,L-ATC by a cell-free extract from the strain. These products were isolated from the reaction mixture and then identified as the L-form. Similar results were obtained with P. putida AJ3865 and unidentified strain TG-3, an ATC-assimilating bacteria. It became clear that L-NCC is an intermediate in the conversion of D,L-ATC to L-cysteine in these Pseudomonas strains. Furthermore, it was suggested that these bacteria have L-ATC hydrolase and L-NCC amidohydrolase.