• 한국미생물·생명공학회지
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• 제25권2호
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• pp.151-158
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• 1997

For the production of potent chitinolytic enzyme from bacteria, screening was carried out. Of 100 samples from soil, fresh water and sea water collected from the Kyung-gi area, 7 strains of chitinolytic bacteria were isolated. Among them, Aeromonas hydrophila 5-3K showed the highest chitinolytic activity. Culture conditions of Aeromonas hydrophila for the production of chitinolytic enzyme were inverstigated and lytic enzyme was fractionated by the use of ammonium sulfate and Sephadex G-100. Maximum production of chitinolytic enzyme was obtained at pH 7.0 and 30$\circ$C with chitin concentration between 0.2% and 1.0%. Conditions for the enzyme production were optimized including fermentor cultivation. The chitinolytic system of Aeromonas hydrophila 5-3K was composed of two enzymes, chitinase and chitobiase.

• 한국식물병리학회지
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• 제11권1호
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• pp.47-52
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• 1995

One hundred and thirty bacterial isolates with high chitinolytic activity on chitin agar media were isolated and identified. Most of the isolates were Aeromonas hydrophila (110 isolates), and the others were Serratia marcescens (11 isolates), Aeromonas caviae (3 isolates), Chromobacterium violaceum strain C-61 (2 isolates), Chromobacterium violaceum strain C-72 (1 isolate) and unknown species (3 isolates). Among them, C. violaceum strain C-61 had highest chitinolytic activity and fungal growth inhibition on PDA. This bacterium also inhibited the growth of Rhizoctonia solani, Sclerotinia scelrotiorum, Phytophthora capsici and Pythium ultimum, but it didn't inhibit the growth of Fusarium oxysprum and Fusarium solani. C. violaceum strain C-61 suppressed damping-off of eggplant caused by R. solani. Populations of the chitinolytic bacteria such as Aeromonas hydrophila, Serratia marcescens, Aeromonas caviae, Chromobacterium violaceum strain C-61 and Chromobacterium violaceum strain C-72 introduced into R. solani-infested soil were continuously decreased until 20 days after treatment, but their populations except A. caviae were not changed significantly and maintained over 5$\times$104 CFU per g of soil thereafter.

• Fisheries and Aquatic Sciences
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• 제2권1호
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• pp.105-111
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• 1999

In order to produce functional chitin oligosaccharides, a chitinolytic bacterium was newly screened from the viscera of Korean bony fishes, and identified as Bacillus sp. LJ-25. For the production of chitinolytic enzymes, $1.0\%$ nutrient broth and $0.3\%$ colloidal chitin were used as nitrogen and carbon source, respectively. The optimal temperature, initial pH and concentration of NaCl for the enzyme production by Bacillus sp. LJ-25 were $30^{\circ}C$ 6.5-7.0 and $1.0\%$, respectively. The enzyme activity of Bacillus sp. LJ-25 increased until the incubation time of 168 hr, followed by a decrease in activity.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 1998년도 수산관련공동학술대회발표요지집
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• pp.222-223
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• 1998

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 1986년도 추계학술대회
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• pp.522.3-523
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• 1986

A Screening test was carried out for chitin-decomposing bacteria. In 100 samples from soil, fesh water and sea water, 7 strains of Chitinolytic bacteria were isolated. 5-3K which exhibited the highest chitinase activity was identified as Aeromonas hydrophila and cultural conditions from maximum chitinase production were determined. Optimum Chitinase production was obtained at pH 7, 33eC and with chitin concentration greater tham 0.2% Under optimal conditions, high yields of Chitinase were obtained in 16-30 hours. Chitinase was purified by ammonium sulfate precipitation and sephadex G-100 gel-filtration from the culture filtrgte.

• 식물병연구
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• 제20권2호
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• pp.112-118
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• 2014

본 연구는 키틴분해세균, 키틴 및 그들의 산물이 함유된 미생물제가 오이의 뿌리혹선충을 어느 정도 방제할 수 있는가를 알아보기 위하여 실시되었다. 미생물제는 3종의 키틴분해세균(Chromobacterium sp. C-61, Lysobacter engymogenes 및 Serratia plymuthica)을 키틴 + 최소기본배지에서 배양함으로서 조제되었다. 포트 조건에서 미생물제는 대조구에 비하여 오이의 생육을 증진시키고, 뿌리혹과 뿌리혹선충의 밀도를 감소시켰다. 비닐하우스에서 정식한 날부터 물 대신에 75배 희석된 미생물제를 5일 간격으로 6회 오이에 점적 관수하면, 30일 후 오이의 초장이 7% 증가하고 근권의 뿌리혹선충 밀도는 78% 감소되며, 60일 후에는 10%의 초장 증가와 69%의 밀도 감소를 나타냈다. 아울러, 이러한 효과는 미생물제가 직접 접촉된 부분에서만 일어났다. 한편, 뿌리혹선충에 심하게 감염되어 생육이 저조한 오이에 미생물제 원액을 10일 간격 3회 토양 관주하였을 경우에는 무처리구에서 37%의 오이가 죽었지만 처리구에서는 한 주도 죽지 않고, 37%의 생육 증가와 82%의 선충 감소를 보여 주었다. 따라서 본 미생물제는 오이 뿌리혹선충의 방제에 활용 가능하리라 판단되었다.

• 한국식물병리학회지
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• 제11권3호
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• pp.258-264
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• 1995

Production and some properties of chitinolytic enzymes were investigated by 80% ammonium sulfate precipitates (crude enzymes) from culture supernatant of antagonistic bacteria, Chromobacterium violaceum strain C-61 and strain C-72, Aeromonas hydrophila, Aeromonas caviae, and Serratia marcescens. The maximum production of chitinase was obtained from the 3-day culture at 28$^{\circ}C$ in C. violaceum stains, the 6-day culture in S. marcescens, and the 2-day culture in A. hydrophila and A. caviae. In the optimum culture periods, chitinase activity of C. violaceum strains C-61 was 1.5, 5.5, 12.0 and 11.3 times higher than those of strain C-72, S. marcescens, A. hydrophila and A. caviae, respectively. However, N,N'-diacetylchitobiase activity was 3.2 times higher in S. marcescens than in C. violaceum strain C-61, and that of Aeromonas spp.was very low. On gels containing glycol chitin, chitinase of C. violaceum strains showed four isoforms of 54-, 52-, 50- and 37-kDa, whereas there were four isoforms of 58-, 52-, 48- and 38-kDa in S. arcescens, three isoforms of 70-, 58- and 54-kDa in A. hydrophila and six isoforms of 90-, 79-, 71-, 63-, 58- and 38-kDa in A. caviae. The chitinase of C. violaceum strain C-61 was most active at pH 7.0 and at 5$0^{\circ}C$ and was stable in ranges of pH 5.0~10.0 for 2 hours and of 0~5$0^{\circ}C$ for 30 min.

• 식물병연구
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• 제13권1호
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• pp.40-44
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• 2007

비닐하우스에서 고추 흰가루병은 1년 내내 발생하는 가장 문제시되는 병해중의 하나이다. 본 연구에서는 키틴 함유배지에서 자란 L. enzymogenes strain C-3와 Chromobacterium sp. strain C-61의 혼합배양액에 의한 흰가루병 방제효과를 평가하였다. 모든 실험에서 고추 잎 뒷면에 분포하는 흰가루는 혼합배양액 살포 3일 후 완전 사라졌다. 그러나 동일 부위에서 새로운 흰가루가 나타나기까지의 기간(방제지속기간)은 살포후의 환경조건에 따라 크게 달랐다. 특히, 오전 9시보다 오후 6시에 살포되었을 경우, 그리고 살포 다음날 비가 왔을 경우에는 그 방제지속기간이 훨씬 더 길었다. 이것은 살포 후의 환경 조건이 병 방제효과에 크게 영향을 미칠 것이라는 것을 암시한다. 배양 원액은 병 발생이 심한 포장에서 5일 간격, 병 발생이 시작되는 포장에서 7일 간격 살포함으로서 95% 이상의 완전한 방제효과를 보여 주었다. 10배 희석 액도 동일 방법으로 살포하였을 경우 81% 이상의 방제 효과를 나타냈다. 따라서 본 배양액은 고추 흰가루병 방제에 실제 이용 가능할 것으로 판단된다.

• 한국어병학회지
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• 제21권3호
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• pp.247-257
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• 2008

To understand the activity of non-specific defence factors in cultured Sebastes, the antibacterial effect of the serum, skin mucus and homogenate of various organs from cultured oblong rockfish (Sebastes oblongus) and rockfish(Sebastes schlegeli) against pathogenic bacteria, Aeromonas hydrophila, Edwardsiella tarda, Vibrio anguillarum, and Streptococcus sp. was compared with that of flounder(Paralichthys olivaceus) and seabass(Leteolabrax japonicus). And the activities of proteolytic enzyme, chitinolytic enzyme and haemolycin as non-specific defence factor were investigated on the oblong rockfish and rockfish. Samples from oblong rockfish showed the highest antibacterial activity by lysoplate assay on agar plate mixed with pathogens, followed in descending order by rockfish, seabass, and flounder. Turbidimetric assay was carried to evaluate the lysozyme activity of fish samples against lyophilized cells of Micrococcus lysodeiktikus. The serum, kidney, liver, stomach, intestine and eyeball of oblong rockfish and the mucus and gill of rockfish appeared to have the highest lysozyme activity among the fish strains investigated. All samples except skin mucus, liver, and eyeball of oblong rockfish and rockfish showed proteolytic enzyme activity. Chitinolytic enzyme activity was showed in random sampling and haemolytic activity was remarkable in oblong rockfish. Therefore, Sebastes strain was proved to have effective defense mechanisms based on the antibacterial activities, and lysozyme, proteolytic enzyme, chitinolytic enzyme, and haemolycin were considered to act as the non-specific defence factor of Sebastes.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권6호
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• pp.482-493
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• 2005

Biomass is originally photosynthesized from inorgainic compounds such as $CO_2$, minerals, water and solar energy. Recent studies have shown that anaerobic bacteria have the ability to convert recalcitrant biomass such as cellullosic or chitinoic materials to useful compounds. The biomass containing agricultural waste, unutilized wood and other garbage is expected to utilize as feed, food and fuel by microbial degradation and other metabolic functions. In this study we isolated several anaerobic, cellulolytic and chitinolytic bacteria from rumen fluid, compost and soil to study their related enzymes and genes. The anaerobic and cellulolytic bacteria, Clostridium thermocellum, Clostridium stercorarium, and Clostridium josui, were isolated from compost and the chitinolytic Clostridium paraputrificum from beach soil and Ruminococcus albus was isolated from cow rumen. After isolation, novel cellulase and xylanase genes from these anaerobes were cloned and expressed in Escherichia coli. The properties of the cloned enzymes showed that some of them were the components of the enzyme (cellulase) complex, i.e., cellulosome, which is known to form complexes by binding cohesin domains on the cellulase integrating protein (Cip: or core protein) and dockerin domains on the enzymes. Several dockerin and cohesin polypeptides were independently produced by E. coli and their binding properties were specified with BIAcore by measuring surface plasmon resonance. Three pairs of cohesin-dockerin with differing binding specificities were selected. Two of their genes encoding their respective cohesin polypeptides were combined to one gene and expressed in E. coli as a chimeric core protein, on which two dockerin-dehydrogenase chimeras, the dockerin-formaldehyde dehydrogenase and the dockerin-NADH dehydrogenase are planning to bind for catalyzing $CO_2$ reduction to formic acid by feeding NADH. This reaction may represent a novel strategy for the reduction of the green house gases. Enzymes from the anaerobes were also expressed in tobacco and rice plants. The activity of a xylanase from C. stercorarium was detected in leaves, stems, and rice grain under the control of CaMV35S promoter. The digestibility of transgenic rice leaves in goat rumen was slightly accelerated. C. paraputrificum was found to solubilize shrimp shells and chitin to generate hydrogen gas. Hydrogen productivity (1.7 mol $H_2/mol$ glucos) of the organism was improved up to 1.8 times by additional expression of the own hydrogenase gene in C. paraputrficum using a modified vector of Clostridiu, perfringens. The hydrygen producing microflora from soil, garbage and dried pelletted garbage, known as refuse derived fuel(RDF), were also found to be effective in converting biomass waste to hydrogen gas.