Abstract: The acdS gene encoding an ACC deaminase was amplified by PCR from genomic DNA of Pseudomonas koreensis JDM-2,and the PCR product was ligated into the pMD18-T vector and then sequenced.The acdS gene was excised from plasmid pMD18ACDS by double digestion with BanHⅠand HindⅢ,and cloned into the prokaryotic expression vector pQE30 to provide plasmid of pQE30ACDS.The ACC deaminase was expressed in Escherichia coli BL21 harboring the plasmid pQE30ACDS by IPTG induction.The sequence analyses showed that the acdS gene was 1 017 bp in length,DNA homology of the acdS genes between the Pseudomonas koreensis JDM-2 and the previously reported different bacterial strains in GenBank was 86% to 99%.The SDS-PAGE analyses showed a single protein band with a molecular weight of 39 kDa expressed in Escherichia coli BL21,and its enzyme activity was 0.214 U/mg.

Key words: Pseudomonas koreensis JDM-2, acdS gene, ACC deaminase, expression