• KSBB Journal
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• 제18권1호
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• pp.8-13
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• 2003

재조합 trehalose synthase 반응을 통하여 트레할로스를 생산하였고, 그 반응조건의 특성들을 조사하고 트레할로스를 정제하였다. 초기 효소반응 조건으로 최적화된 $45^{\circ}C$, pH 7.0를 기본으로 하여 트레할로스 생산을 극대화하기 위해 반응조건들을 장시간 동안 수행하여 조사하였다. 기질농도는 저농도인 1 g/l에서 가장 높은 65.2 % 트레할로스 생산수율을 나타내었다. 초기 효소 반응에서는 $65^{\circ}C$ 까지는 트레할로스 생성량에 차이가 없었으나 장시간 $60^{\circ}C$ 에서 반응할 경우 트레할로스 생성률은 32.9 %로 상당히 낮은 생성률을 나타내었다. 반면 $25^{\circ}C$에서 반응 할 경우 최대 69.2%의 트레할로스 생성량을 보였다. 효소 양에 따른 트레할로스 최종 생산수율은 10, 25, 50 U/g의 효소 양에 따라 각각 62.3, 62.3, 59%로 유사하였으나 최종 트레할로스 생산수율에 이르는 시간이 최대 6시간 앞당겨 짐을 알 수 있었다. 효소반응 크기를 2-L로 증가 시켜 반응하였을 때 그 양상을 조사한 결과 소규모 반응(10 ml 미만)의 경우와 큰 차이가 없이 트레할로스생성량은 60%내외였다. 따라서 이 결과들을 통하여 본 효소를 이용한 트레할로스 생산은 비교적 산업적으로 적용이 용이 할 것으로 사료된다.

• 한국유전체학회:학술대회논문집
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• 한국유전체학회 2003년도 The 12th Korea Genome Conference
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• pp.43.1-43.1
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• 2003

• Journal of Species Research
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• 제6권2호
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• pp.91-100
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• 2017

Five bacterial strains, ES10-3-3-1, KKM10-2-2-1, Ant11, JM10-4-1-3, and KMS4-11 assigned to the genus Deinococcus were isolated from soil samples collected from Namyangju-si in Gyeonggi-do, Gangnam-gu and Dongdaemun-gu in Seoul, Korea. In addition, four bacterial strains, KKM10-2-7-2, JM10-2-5, JM10-2-6-2, and KKM10-2-3 assigned to the genus Hymenobacter were isolated from soil samples collected from Gangnam-gu and Dongdaemun-gu in Seoul, in South Korea. The five Deinococcus species were Gram-stain positive, pink-pigmented, and short-rod or coccus shaped. The four Hymenobacter species were Gram-stain negative, red-pigmented, and short-rod shaped. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strains ES10-3-3-1, KKM10-2-2-1, Ant11, JM10-4-1-3, and KMS4-11 were most closely related to Deinococcus citri $NCCP-154^T$ (with 99.8% similarity), Deinococcus grandis DSM $12784^T$ (99.0%), Deinococcus marmoris DSM $12784^T$ (98.8%), Deinococcus claudionis $PO-04-19-125^T$ (98.7%), and Deinococcus radioresistens $8A^T$ (99.8%), respectively. KKM10-2-7-2, JM10-2-5, JM10-2-6-2, and KKM10-2-3 were most closely related to Hymenobacter algoricola $VUG-A23a^T$ (99.1% similarity), Hymenobacter elongatus $VUG-A112^T$ (99.1% similarity), Hymenobacter gelipurpurascens $Txg1^T$ (99.1% similarity), and Hymenobacter psychrotolerans $Tibet-IIU11^T$ (99.3% similarity), respectively. These nine species have never been reported in Korea; thus, five Deinococcus species are reported in the family Deinococcaceae, order Deinococcales, class Deinococci, phylum Deinococcus-Thermus and four Hymenobacter species are reported in the family Cytophagaceae, order Cytophagales, class Cytophagia, phylum Bacteroidetes.

• Asian-Australasian Journal of Animal Sciences
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• 제17권12호
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• pp.1751-1757
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• 2004

Recombinant heterologous proteins can be produced as insoluble aggregates partially or perfectly inactive in Escherichia coli. One of the strateges to improve the solubility of recombinant proteins is fusion with a partner that is excellent in producing soluble fusion proteins. To improve the production of soluble $\beta$-galactosidase, the gene of Thermus thermophilus KNOUC112 $\beta$-galactosidase (KNOUC112 $\beta$-gal) was fused with thioredoxin gene, and optimization of its expression in E. coli TOP10 was performed. KNOUC112 $\beta$-gal in pET-5b was isolated out, fused with thioredoxin gene in pThioHis C, and transformed to E. coli TOP10. The $\beta$-galactosidase fused with thioredoxin was produced in E. coli TOP10 as dimer and trimer. The productivity of fusion $\beta$ -galactosidase expressed via pThioHis C at 37$^{\circ}C$ was about 5 times higher than that of unfused $\beta$-galactosidase expressed via pET-5b at 37$^{\circ}C$. Inclusion body of $\beta$-galactosidase was formed highly, regardless of the induction by IPTG when KNOUC112 $\beta$ -gal was expressed via pET-5b at 37$^{\circ}C$. Fusion $\beta$ -galactosidase expressed at 37$^{\circ}C$ via pThioHis C without the induction by IPTG was soluble, but the induction by IPTG promoted the formation of inclusion body. Lowering the incubation temperature for the expression of fusion gene under 25$^{\circ}C$ prevented the formation of inclusion body, optimally at 25$^{\circ}C$. 0.07 mM of IPTG was sufficient for the soluble expression of fusion gene at 25$^{\circ}C$. The soluble production of Thermus thermophilus KNOUC112 $\beta$-galactosidase could be increased about 10 times by fusion with thioredoxin, and optimization of incubation temperature and IPTG concentration for induction.

• Journal of Species Research
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• 제7권2호
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• pp.161-180
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• 2018

Fourteen bacterial strains, low10-4-1, J11015, 17J27-22, 17G22-9, 17G9-4, 17Bio_15, 17gy_33, 17SD1_21, Strain8, 17Sr1_17, J21014T, H31021, 17J49-9, and 17J80-6 assigned to the phylum Actinobacteria, Bacteroidetes, Deinococcus-Thermus, and Firmicutes were isolated from soil samples. Phylogenetic analysis based on 16S rRNA gene sequence revealed that strains low10-4-1, J11015, 17J27-22, 17G22-9, 17G9-4, 17Bio_15, 17gy_33, 17SD1_21, Strain8, 17Sr1_17, J21014T, H31021, 17J49-9, and 17J80-6 were most closely related to Marmoricola aurantiacus (98.9%), Calidifontibacter indicus (99.8%), Gordonia soli (98.8%), Rhodococcus globerulus (99.5%), Pseudarthrobacter siccitolerans (99.1%), Hymenobacter qilianensis (98.7%), Hymenobacter terrae (99.0%), Deinococcus yunweiensis (99.2%), Deinococcus proteolyticus (99.7%), Domibacillus indicus (99.2%), Exiguobacterium mexicanum (100.0%), Kurthia senegalensis (99.1%), Lysinibacillus composti (99.6%), and Bacillus loiseleuriae (99.3%). These fourteen species have never been reported in Korea, therefore we report them here for the first time.

• 한국유전체학회:학술대회논문집
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• 한국유전체학회 2002년도 The 11th Korea Genome Conference
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• pp.49.1-49.1
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• 2002

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.83-86
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• 2002

Thermus caldophilus로부터 TDP-glucose 4,6-degydratase (TDPDH) 유전자를 분리하고 염기서열을 결정하고, 결정된 염기서열에 해당하는 유전자를 발현벡터에 삽입하고, 발현벡터를 대장균에 형질전환시켜 배양함으로써 TDP-glucose 4,6-dehydratase를 대량 생산하였다. 본 연구의 TDP-glucose 4,6-dehydratase는 주반응으로 TDP-4-keto-6-glucose를 합성하고, 여러 가지 당을 디옥시당으로 합성하는 효과가 있다.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2001년도 Proceedings of 2001 International Symposium
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• pp.165-168
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• 2001

Regulation of pyrimidine nucleotide synthesis has been studied extensively in enteric bacteria and Bacillus species. Varieties of control modes have been proposed for regulation of pyrimidine nucleotide biosynthetic (pyr) genes. In Bacillus caldolyticus and B. subtilis, it has been proved that pyrimidine de novo biosynthetic operon is controlled by a regulatory protein PyrR-mediated attenuation. Another Gram-positive bacteria including Enterococcus faecalis, Lactobacillus plantarum, and wctococcus lactis have been found to constitute a pyr gene cluster containing the pyrR gene. In addition, it has been proposed that the structure of the 5' leader region of the Gram-negative extreme thermophile Thermus strain Z05 pyr operon provides a novel mechanism of PyrR-dependent coupled transcription-translation attenuation. Bacterial genome sequencing projects have identified the PyrR homologues in Haemophilus influenzae, Synechocystis sp., Mycobacterium tuberculosis, Streptococcus pneumoniae, S. pyogenes, and Clostridium acetobutylicum, which are currently investigating for their physiological functions.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2003년도 제39회 학술심포지움
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• pp.23-37
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• 2003

A novel inhibitor against maltose-producing a-amylase was prepared via stepwise degradation of a high molecular weight acarbose (HMWA) using Thermus maltogenic amylase (ThMA). The structure of the purified inhibitor was determined to be ${\alpha}$-D-glucopyranosyl-${\alpha}$-acarviosinyl-D-glucopyranose (GlcAcvGlc). Progress curves of p-nitrophenyl-${\alpha}$-D-maltoside (PNPG2) hydrolysis by various amylolytic enzymes, including maltogenase (MGase), ThMA, and cyclodextrinase(CDase) I-5, in the presence of acarbose or GlcAcvGlc indicated a slow-binding mode of inhibition. The inhibition potency of GlcAcvGlc for MGase, ThMA, and CDase I-5 was 3 orders of magnitude higher than that of acarbose.

• Journal of Microbiology and Biotechnology
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• 제9권4호
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• pp.381-385
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• 1999

Taq DNA polymerase from Thermus aquaticus has been shown to be very useful in a polymerase chain reaction. Taq DNA polymerase has a domain at the amino terminus (residues 1 to 290) that has 5'-3' exonuclease activity and a domain at the C-terminus that catalyzes the polymerase reaction. Taq DNA polymerase is classified into the Pol I family, which is represented by E. coli DNA polymerase I. The alignment of amino acid sequences for the 5'-3' exonuclease domains of the Pol I family DNA polymerases shows ten highly conserved carboxylic amino acids. Crystallographic studies suggested that six of the carboxylic amino acids are clustered within a 7 $\AA$ radius by chelating three metal ions in the active site. Those six carboxylic residues are mutagenized to alanines in order to better understand their function. All six carboxylic residues, Asp l8, Glu1l7, Asp1l9, Asp120, Asp142, and Aspl44, are crucial for catalysis of 5'-3' exonuclease.