Journal of Microbiology

Chae, Jong Chan

4 Articles

Catabolism of 4-Hydroxybenzoic Acid by Pseudomonas sp. DJ-12: Karegoudar, Timmanagouda B. , Chae, Jong Chan , Kim, Chi Kyung; J. Microbiol. 1999;37(3):123-127.

Abstract PDF: A Pseudomonas sp. strain DJ-12 isolated by 4-cholrobiphenyl enrichment culture technique is capable of utilizing 4-hydroxybenzoic acid as a sole source of carbon and energy. The bacterium catabolized 4-hydroxybenzoic acid through the intermediate formation of protocatechuic acid, which was further metabolized. The cell free extracts of pseudomonas sp. DJ-12, grown on 4-hydroxybenzoic acid showed higher activities of 4-hydroxyenzoate 3-hydroxylase and protocatechuate 4,5-dioxygenase, but the activity of catechol 2,3-dioxygenase was lower. The results suggest that 4-hydroxybenzoic acid is catabolized via protocatechuic acid rather than catechol or gentisic acid in this bacterium and that the protocatechuic acid formed was metabolized through a metacleavage pathway by protocatechuate 4,5-dioxygenase.

Dechlorination of 4-Chlorobenzoate by Pseudomonas sp. DJ-12: Chae, Jong Chan , Kim, Chi Kyung; J. Microbiol. 1997;35(4):290-294.

Abstract PDF: 4-Chlorobiphenyl-degrading Pseudomonas sp. DJ-12 was able to degrade 4-chlorobenzoate(4CBA), 4-iodobenzoate, and 4-bromobenzoate completely under aerobic conditions. During. the degradation of 4CBA by Pseudomonas sp. DJ-12, chloride ions were released by dechlorination and 4-hydroxybenzoate was produced as an intermediate metabolite. The NotI-KNA fragments of pKC157 containing dechlorination genes hybridized with the gene encoding 4CBA:CoA dehalogenase of Pseudomonas sp. CBS3 which is responsible for the hydrolytic dechlorination of 4CBA. These results imply that Pseudomonas sp. DJ-12 degrades 4CBA to 40hydroxybenzoate via dechlorination as the initial step of its degradativ pathway. The genes responsible for dechlorination of 4CBA were found to be blcated on the chromosomal DNA of Pseudomonas sp. DJ-12.

Cloning and expression in E. coli of the HOPDA hydrolase gene from pseudomonas sp. P 20: Lim, Jong Chul , Chae, Jong Chan , Kim, Hyong Bai , Kim, Chi Kyung; J. Microbiol. 1996;34(4):349-354.

Abstract PDF: Pseudomonas sp. P20 is a natural isolate which is capable of degrading biphenyl and 4-chlorobiphenyl. From a clone of pCK1022 harboring pcbCD genes of Pseudomonas sp P20, a pcbD gene encoding 2-hydroxy-6-oxo-6-phenylhexa-2, 4-dienoic acid (HOPDA) hydrolase was subcloned in Escherichia coli XL-1-Blue by using pBluescript SK(+) vector. The 2.8-kb HindII fragment harboring the pcbD gene cloned in pCK 1024 had a single site for each of XhoI, SalI, BstXI, and XbaI restriction enzymes. Escherichia coli CK1024 had a single site for each of XhoI, SalI, BstXI, and XbaI restriction enzymes. Escherichia coli CK1024 carrying pCK0124 degraded HOPDA to benzoate and 2-hydroxypenta-2, 4-dienoate by HOPDA hydrolase encoded by pcbD gene as effectively as E coli CK 1022 HARBORING pcbCD genes.

Cloning of the Gene Responsible for Dechlorination of 4-Chlorobenzoate from Pseudomonas sp. DJ-12: Chae, Jong Chan , Kim, Young Chang , Kim, Young Soo , Kim, Chi Kyung; J. Microbiol. 1995;33(1):34-39.

Abstract PDF: The gene responsible for dechlorination of 4-chlorobenzoate(4CBA) was cloned from chromosomal DNA of Pseudomonas sp. DJ-12 in Escherichia coli XL1-Blue by using pBluescript SK(+) phagemid vector. Two recombinant plasmids of pCJ1 and pCJ2 carrying dechlorinase gene were constructed. The inserted DNAs in the pCJ1 and pCJ2 were found to have the fragment of 9.5 kb carrying dechlorinase gene, but they were oriented in opposite direction. The inserted DNA of 3.4kb in the pCJ101 subclone carrying dechlorinase gene had two restriction sites for AccI and each one site for HincII, KpnI, PstI, and SacIi but the dechlorinase gene in pCJ101 was found to be placed over the HincII site. The dechlorinase fenes in the recombinant cells of E. coli CJ1 and CJ101 were well expressed to show the dechlorination activity of 4CBA. The proteins encoded by dechlorinase genes in E. coli CJ1 and CJ101 were about 49 kDa in molecular weight. But this protein was not produced by E. coli CJ102, CJ103 and E. coli XL1-Blue. Therefore, the proteins produced by Pseudomonas sp. DJ-12 and the cloned cells of E. coli CJ1 and CJ101 were thought to be the dechlorinase enzyme which was the product of dechlorinase gene.

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