• 한국균학회지
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• 제23권2호통권73호
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• pp.190-195
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• 1995

고추탄저병(Colletotrichum gloeosporioides)에 대한 생물학적방제 능력을 가지는 엽권미생물을 선발하기 위하여 38과 87종의 약용식물로부터 243균주의 세균과 51균주의 사상균 그리고 30균주의 효모를 분리하여 이들에 대하여 항진균활성검정을 in vitro 및 in vivo에서 실시한 결과는 다음과 같다. 분리된 엽권미생물 중에서 PDA 배지 대치배양에서 10 mm 이상의 생육저지대를 형성하는 4개의 엽권미생물이 선발되었다. 선발된 4개의 세균균주 KB6, KB12, KB13 및 KB14의 PDB 배양여액 중에서 KB12 균주가 균사생장 억제율이 가장 높았다. 액체배양여액 처리에서 푸른 고추보다 붉은 고추에서 방제효과가 컸다. Bacterial cell 처리에서는 푸른 고추나 붉은 고추에서도 높은 방제효과가 있었다. 선발된 4개의 세균균주들은 모두 Bacillus subtilis로 동정되었다.

• Mycobiology
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• 제36권4호
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• pp.266-269
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• 2008

Twenty isolates of Bacillus species obtained from livestock manure composts and cotton-waste composts were tested for their antagonistic effects in vitro against three green mold pathogens of mushrooms (Trichoderma harzianum, T. koningii, and T. viridescens). However, there exists a possibility Bacillus species may have antagonistic effects against mushrooms themselves, and thus the same 20 isolates were tested in vitro against three species of mushrooms (Flammulina velutipes, Lentinus edodes, and Pleurotus ostreatus). Of the 20 Bacillus species isolates tested, two inhibited mycelial growth of T. harzianum, seven that of T. koningii, and eight that of T. viridescens. Importantly, the bacterial isolates M27 and RM29 strongly inhibited mycelial growth of all the Trichoderma spp. isolates tested. The isolate M27 was subsequently identified as the most effective in inhibiting mycelial growth of all the Trichoderma species. Interesting results of the effect Bacillus isolates had upon the mushroom species followed. It was found that most Bacillus isolates except 5T33 at least somewhat inhibited mycelial growth of the three mushroom species or some of the mushrooms. Furhermore, the antagonistic effects of the bacterial isolates against the three species of mushrooms varied depending on the mushroom species, suggesting a role for mushroom type in the mechanism of inhibition. The bacterial isolates M27 and RM29 were identified as having the most antagonistic activity, inhibiting mycelial growth of all the Trichoderma spp. as well as mycelial growth of the three species of mushrooms. These results suggest that the bacterial isolates and their antagonistic effects on green mold pathogens should be further studied for their practical use for biological control of green mold in the growing room of the mushrooms.

• The Plant Pathology Journal
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• 제23권4호
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• pp.239-244
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• 2007

MicroTom is a miniature tomato plants with various properties that make it as a model system for experiments in plant molecular biology. To extend its utility as a model plant to study a plant - bacterial wilt system, we investigated the potential of the MicroTom as a host plant of bacterial wilt caused by Ralstonia solanacearum. We compared the disease progress on standard tomato and MicroTom by two inoculation methods, root dipping and soil drenching, using a race 1 strain GMI1000. Both methods caused the severe wilting on MicroTom comparable to commercial tomato plant, although initial disease development was faster in root dipping. From the diseased MicroTom plants, the same bacteria were successfully reisolated using semiselective media to fulfill Koch's postulates. Race specific and isolate specific virulence were investigated by root dipping with 10 isolates of R. solanacearum isolated from tomato and potato plants. All of the tested isolates caused the typical wilt symptom on MicroTom. Disease severities by isolates of race 3 was below 50 % until 15 days after inoculation, while those by isolates of race 1 reached over 50% to death until 15 days. This result suggested that MicroTom can be a model host plant to study R. solanacearum - plant interaction.

• Fisheries and Aquatic Sciences
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• 제9권2호
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• pp.57-63
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• 2006

A bacterial strain capable of hydrolyzing carrageenan was isolated from the coast of Busan in Korea. The isolated strain (HS5322) is aerobic, gram-negative, rod-shaped, and motile. Comparison of the 16S rDNA of the isolate with that of known Pseudomonas sp. showed that sequence similarity was at most 95%, implying that the isolate is a new Pseudomonas species. The organism grew optimally at NaCl concentrations of 2.0 to 2.5%. The optimum temperature and pH for carrageenase production in a 72-h flask culture containing 1% carrageenan was $20^{\circ}C$ and pH 8.5, respectively. Of the synthetic substrates tested, the highest enzyme activity was obtained with p-nitrophenyl ${\beta}$-D-galactopyranoside.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.88.1-88
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• 2003

Antogonistic bacteria against Rhizoctonia solani and Pythium spp., causing serious damage to golf course grasses, were isolated from the top soil of several golf courses in Korea. The isolate of Limk0102 was selected as the biological agent by characterization of antifungal activity, large scale preparation, fungicides tolerance and ecological fitness to the targe environment. The isolate was identified as Bacillus subtilis by biochemical and physiological characterization, and 165 rDNA sequence analysis. The bacterial agent was formulated as a granule type by seeding it on fine sand. The formulated agent showed high recovery rate (more than 10$\^$8/ cells/g sand) even after 6 month-storage at room temperature with similar antifungal activity with that of original cells. In vitro, the biological agent successfully exhibited antagonistic performance on bentgrass inoculated with R. solani or Pythium spp. isolated from the diseased grasses on golf courses. Field evaluation on disease control activity and ecological fitness of the agent is now under going on several golf courses.

• Journal of Microbiology and Biotechnology
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• 제16권5호
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• pp.731-739
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• 2006

A bacterial strain HJ-14 was isolated as a producer of antioxidants from the coast of Jinhae in Korea. The isolate showed 43.4mol% of G+C content, and contained dihydrogenated ubiquinone with Q8 as a major quinone. Chemotaxonomic analysis as well as phylogenetic analysis, based on the 16S rDNA sequence, identified the isolate as a member of Alteromonas macleodii. For antioxidant production, the optimum medium composition was determined to be 3% dextrin, 0.5% ammonium sulfate, and 2-6% sodium chloride. Optimum culture conditions for production of antioxidant materials with strain HJ-14 were at pH 6.0-8.0 and $25-37^{\circ}C$. The chloroform extract of strain HJ-14 broth showed 1.96-17.5-fold higher antioxidant activity than other organic solvents in term of electron donating ability.

• Journal of Microbiology and Biotechnology
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• 제20권2호
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• pp.410-414
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• 2010

A bacterial strain, 13-$25^T$ with xylanolytic activity isolated from a single soil sample, was characterized with respect to its phenetic and phylogenetic characteristics. The cells of the isolate are Gram-staining variable rods, but spore formation was not observed. This strain is catalase- and oxidase-positive, and able to degrade starch and xylan. The predominant fatty acids are anteiso-$C_{15:0}$, $C_{16:0}$, and iso-$C_{16:0}$. The major respiratory quinone is menaquinone 7(MK-7), with a polar lipid profile consistent with the genus Cohnella. The DNA G+C content is 54.3 mol%. The 168 rRNA gene sequence analysis indicates that this organism belongs to the genus Cohnella, with Cohnella panacarvi as the closest phylogenetic neighbor. Low levels of 168 rRNA gene sequence similarity (<97.0%) with respect to other taxa with published names and the identification of distinctive phenetic features in the isolate indicate that the strain 13-$25^T$ represents a novel species of the genus Cohnella, for which the name Cohnella damensis sp. novo is proposed. The type strain is 13-$25^T$ (=CCTCC AB $208103^T$=KCTC $13422^T$).

• 한국식품과학회지
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• 제31권3호
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• pp.734-738
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• 1999

우리밀을 이용하여 AACC method 10-10B로 만든 식빵을 이용하여 균을 검출하여 A color of atlas of Bacillus species에 나와있는 동정법에 의해 실험한 결과, rope bacteria로 알려진 Bacillus subtilis의 종류인 것으로 잠정적으로 확인하였다. 이 균의 활성은 pH 6.0을 기점으로 그 이상에서는 매우 좋았으며, pH 5.6 이하에서는 억제되었다. 또한 $90^{\circ}C$에서 10분간의 열처리에서도 다시 활성이 일어나는 것으로 조사되었다. 결국 rope bacteria의 발생은 제조공정에서 적절한 발효과정을 실행하여 제품의 pH를 낮추거나, 충분한 굽기과정으로 내부의 온도를 높이면 억제될 수가 있는 것으로 사료된다.

• 미생물학회지
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• 제36권1호
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• pp.58-63
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• 2000

공업단지 폐수로부터 benzoate에 대하여 분해능을 보이는 균주를 분리하여 생화학적 특성과 세포 지방산 분석을 실시하여 동정한 결과 Klebsiella oxytoca로 밝혀졌다. 따라서 이 균주를 Klebsiella oxytoca strain C3O2라 명명하였으며 여러 가지 방향족 탄화수소에 대한 분해특성을 알아본 결과, benzoate 외에 catechol, protocatechuate, 4-hydroxybenzoate에 대한 분해능이 우수하였으며, 특히 benzoate와 catechol에 대하여 높은 분해능을 보였다. Klebsiella oxytoca C3O2 균주의 catechol 분해능에 대한 환경요소의 영향을 실험한 결과, $30^{\circ}C$와 pH 7.0에서 그리고 0.5~1.0 mM의 농도에서 왕성한 생장과 분해능을 보였다.

• Journal of Microbiology and Biotechnology
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• 제19권6호
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• pp.588-595
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• 2009

A bacterial strain, YK-2, was isolated as a producer of trans glutaminase from a forest soil sample of Daegu, Korea. The isolate showed a G+C content of 72.7 mol%, contained meso-$A_2pm$ as the cell-wall amino acid, and possessed menaquinone MK-9 ($H_6$) and menaquinone MK-9 ($H_8$) at a ratio of 6:4. The chemotaxonomic analysis, as well as phylogenetic analysis based on the 16S rDNA sequence, identified the isolate as a member of Streptomyces platensis. For transglutaminase production, the optimum medium composition was determined to be 2% glucose, 1% polypeptone, 1% soy tone, and 0.1% $MnCl_2$. The transglutaminase was stable within the pH range of 5.0-9.0 and $30-45^{\circ}C$, and the optimum pH and temperature were pH 8.0 and $45^{\circ}C$, respectively, without any requirement for $Ca^{2+}$.