Biotransformation of DL-2-Amino-Delta²-Thiazoline-4-Carbonic Acid to L-Cysteine Using a Newly Isolated Pseudomonas sp. Zjwp-14

A bacterial strain Pseudomonas sp. Zjwp-14 was screened out from soil, and used for the biotransformation of DL-2-amino-Δ²-thiazoline-4-carbonic acid to L-cysteine. This strain was identified based on its morphological, physiological characterization, 16S rDNA sequence determination and phylogenetic analysis. The bioconversion process was optimized by examining some key factors including cell cultivation time, buffer pH, metal ions, aeration (anaerobic/aerobic) and substrate concentration. L-cysteine productivity reached 4.24 g·1^-1 in 6 h under optimal conditions: cells were cultivated for 12 h, and then resuspended in pH 8.0 phosphate buffer contationing 10 g·1^-1 in of DL-ATC as substrate, with the addition of 2 mM MnSO₄·4H₂O, incubated in still culture flashing with N₂ atmosphere at 42 oC for 6 h. The results suggested that Pseudomonas sp. Zjwp-14, a bacterial isolate, has applied potential for enzymatic production of L-cysteine.