https://repository.kopri.re.kr/handle/201206/5165 2026-04-07T05:39:57Z 2026-04-07T05:39:57Z 김주영 Hong, Soon Gyu Yim, Joung Han Kim, Dockyu Cho, Kyeung Hee https://repository.kopri.re.kr/handle/201206/7839 2022-03-24T07:12:11Z 2008-01-01T00:00:00Z

Title: Benzoate Degradation at low temperature by psychrotrophic Pseudomonas orientalis KOPRI 25931 Authors: 김주영; Hong, Soon Gyu; Yim, Joung Han; Kim, Dockyu; Cho, Kyeung Hee Abstract: The psychrotrophic Pseudomonas orientalis KOPRI 25931 was originally isolated from soil on the Alps, Austria, for the ability to grow on benzoate as the sole carbon and energy source. KOPRI 25931 was able to grow on a wide range of temperatures (5-30 °C), having an optimal temperature of 30 °C and showing a capacity to degrade benzoate even at 5 °C. It indicates that KOPRI 25931 is a cold-adapted hydrocarbon degrader possessing cold-active catalytic enzymes. It was identified using phylogenetic analysis on the basis of 16S rRNA gene sequence. The growth substrate range experiments demonstrated that it has also the ability to grow on various hydrocarbon substrates including phenol, toluene, phthalate, and naphthalene. To study the benzoate degradation pathway in molecular level, PCR amplification was carried out with KOPRI 25931 genomic DNA and a degenerate primer set, which has been designed for the genes of aromatic dioxygenase large subunits. Successfully, a PCR product containing a gene fragment of multi-component aromatic dioxygenase was amplified, and then analyzed to be similar (93% identity) to an anthranilate dioxygenase large subunit from a Pseudomonas fluorescens strain. Now, RACE- and Inverse-PCR experiments are in progress to obtain a full ORF encoding a multi-component aromatic dioxygenase system, which might be a useful cold-active enzyme used in future industrial bioconversion processes.

2008-01-01T00:00:00Z Kim, Dockyu Ki Young Choi Kim, Eungbin https://repository.kopri.re.kr/handle/201206/7838 2022-03-24T07:12:00Z 2008-01-01T00:00:00Z

Title: Temperature-induced Loss of Linear Catabolic Megaplasmid (pDK2) in Rhodococcus sp. Strain DK17 Authors: Kim, Dockyu; Ki Young Choi; Kim, Eungbin Abstract: The actinomycete Rhodococcus sp. strain DK17 is able to grow on various alkylbenzenes including benzene, toluene, ethylbenzene, and o-xylene (BTEX). DK17 possesses three linear megaplasmids (380-kb pDK1, 330-kb pDK2, and 750-kb pDK3). The versatile metabolic capacity of DK17 is encoded on the catabolic linear pDK2, which has been previously shown to be partially deleted or even lost when DK17 cells exposed to UV light. However, complete loss of pDK2 at a higher rate of 2.5% was observed to spontaneously occur from several DK17 cells which were heat-treated at 37℃ for 48.8 min (the doubling time of DK17 at optimal 30℃). Due to the absence of the functional catabolic pDK2, all the mutants were unable to grow on ethylbenzene selected as a representative of alkylbenzene substrates, but retained the ability to degrade phthalate. The loss of pDK2 might be attributed to an innate instability of linear megaplasmids, especially in replication during cell division, at a higher ambient temperature above the host's optimal range. It should be further investigated to conclude whether this is a common phenomenon among linear megaplasmids or not.

2008-01-01T00:00:00Z Kim, Dockyu Jung Nam Choi Ki Young Choi Choong Hwan Lee Kim, Eungbin https://repository.kopri.re.kr/handle/201206/7800 2022-03-24T07:13:46Z 2008-01-01T00:00:00Z

Title: Initial Degradative Pathways for Tetralin and Indene by Rhodococcus sp. strain DK17 Authors: Kim, Dockyu; Jung Nam Choi; Ki Young Choi; Choong Hwan Lee; Kim, Eungbin Abstract: Rhodococcus sp. strain DK17, originally isolated for the ability to grow on o-xylene, was characterized to initiate the oxidative metabolism with alkylbenzene dioxygenase (AkbA1A2A3). Tetralin and indene are bicyclic compounds containing one aromatic ring plus one alicyclic ring, the structure of which is similar to that of o-xylene. DK17 was tested to characterize the metabolic pathway(s) of tetralin and indene. The initial metabolism of tetralin was shown to proceed via hydroxylation of the aromatic ring at positions C-1 and C-2, resulting in corresponding 5,6,7,8-tetrahydro-1,2-naphthalene diol. While the alicyclic ring of indene was dihydroxylated on an unsaturated double bond at C-1 and C-2 to indan-1,2-diol, which subsequently dehydrogenated to re-cyclized 1,2-indenediol.

2008-01-01T00:00:00Z