Study on L-cystine Conversion Technology by Pseudomonasputida TS1138

Abstract:

A technology of L-cystine production was studied in this paper, which included microbial enzymatic conversion of DL-2-amino-?2-thiazoline-4-carboxylic acid (DL-ATC) to L-cysteine, subsequent oxidization of L-cysteine to L-cystine and its purification. The cells of Pseudomonas putida TS1138 could be repetitively used as the enzyme sources to convert the substrate DL-ATC to L-cysteine. After being oxidated by 2% dimethy-sulforide (DMSO), L-cystine could be harvested and further purified by the positive ion-exchange resin 001×7. High Performance Liquid Chromatography (HPLC) identified the purified L-cystine as having a total recovery of 78.55% and purity of 99.12%. This study demonstrated an efficient and convenient method for L-cystine production, which overcame the instability of enzymes, troublesome procedures and high cost of enzyme immobilization as contrasted to the traditional method. All in all, it provides a new approach for industrial production of L-cystine as well as L-cysteine.