• Korean Journal Plant Pathology
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• v.12 no.4
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• pp.407-414
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• 1996

벼 담수직파재배에서 Pythium arrhenomanes 1398에 의한 벼목썩음병의 발병 억제효과가 높은 biological control agent를 배지와 growth chamber 검정을 통하여 선발하고 생물학적 방제 효과를 온실에서 검정한 결과 공시한 66 세균 중 91-110 균주에 의해서만 벼모썩음병의 발병이 억제되었다. CMA 배지 검정에서는 P. arrhenomanes 1398 균주만을 접종한 볍씨는 100% 발병율을 보인 반면 91-110 균주와 P. arrhenomanes 1398 균주를 함께 처리한 경우에는 25.0%가 발병되었으며, 이 효과는 metalaxyl을 처리한 볍씨에서의 21.7% 발병율과 유사하였다. Growth chamber 검정에서는 P. arrhenomanes 1398 균주만을 접종한 볍씨는 27.7% 모 출아율을 보인 반면 91-110 균주와 함께 처리하면 59.1%가 출아되었다. 그러나 91-110 균주에 의한 발병 억제효과는 50% household bleach로 표면 소독한 볍씨에서만 인정되었으며, 이 소독한 볍씨를 91-110 균주의 세균 부유액에 침지하여 3시간 진탕한 후 그 부유액을 따라내고 24시간 배양한 것이 진탕하지 않고 배양한 것에 비하여 모출아율이 54.3%에서 65.7%로 증가되었다. 91-110 균주와 P. arrhenomanes 1398 균주를 함께 처리한 볍씨의 출아율은 62.3%로서 P. arrhenomanes 1398 균주만을 접종한것의 30.8%에 비하여 높았다. 이상과 같이 담수직파한 벼모썩음병의 발병 억제효과가 높은 91-110 균주는 Bacillus brevis로 동정되었다.

• Applied Biological Chemistry
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• v.33 no.3
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• pp.239-246
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• 1990

Monascus anka strains with higher pigment production were developed using UV mutation and natural selection. To obtain organic solvent soluble pigments from Monascus anka, the following culture conditions were compared : standing and shaking culture with Nishikawa's medium, and shaking culture with Lin's medium. Shaking culture in Lin's medium exhibited decrease in solvent-soluble intracellular pigments after initial increase. The decrease was accompanied by the increase in water-soluble extracellular pigments. Monascus anka preferred sucrose and ethanol among 7 carbon sources tested. Treatment of sterol biosynthesis inhibitors, $({\pm})$-miconazole and chlorocholine chloride(CCC) , directed carbon pool to the biosynthetic pathway leading to the pigments with CCC's more pronounced effect. Two dimensional TLC revealed at least 7 yellow pigments suggesting existence of hereto unreported pigment. One of the most abundant yellow pigments was isolated and found to be ankaflavin by NMR and MS analysis.

• Journal of the Korean Wood Science and Technology
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• v.24 no.4
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• pp.74-81
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• 1996

리그닌분해능(分解能)이 높은 균주(菌株)로 선발(選拔)된 Coriolus versicolor-13 (CV-13), LKY-7 및 LKY-12세 균주(菌株)에 대하여 균체외(菌體外) laccase 생산(生産)을 검토(檢討)하였다. Glucose-peptone broth에서 균체외(菌體外) laccase활성(活性)은 CV-13의 경우 3일 이상배양후(以上培養後)에 나타났고 LKY-7과 LKY-12균주(菌株)의 laccase 활성(活性)은 배양(培養) 2일째에 검출(檢出)되었다. 탄소원(炭素源)으로서는 maltose가 glucose와 비슷한 laccase 생산효과(生産效果)를 나타냈고 질소원(窒素源)으로서는 유기태질소(有機態窒素)가 무기태(無機態) 질소(窒素)보다 효과적(效果的)이었다. Laccase 유도물질(誘導物質)로서는 2,5-Xylidine이 가장 우수하였으며 1mM 이하(以下)의 농도(濃度)에서는 유도효과(誘導效果)가 크게 나타났으나 1.5mM 이상(以上)의 농도(濃度)에서는 laccase생산(生産)이 억제(抑制)되었고, 균사생장(菌絲生長) 초기(初期)에 첨가(添加)하는 것이 효과적(效果的)으로 나타났다. SDS-PAGE 후, CV-13 균주(菌株)의 균체외(菌體外) 단백질(蛋白質)에서는 약 69, 66, 25, 23, 19kDa 크기의 laccase band가 5개 나타났고 LKY-7 균주(菌株)에서는 27kDa과 19kDa 크기의 2개 band가, LKY-12 균주(菌株)에서는 22, 20, 17kDa 크기의 laccase band가 3개 나타났다.

• Journal of Bio-Environment Control
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• v.16 no.3
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• pp.252-257
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• 2007

This study was carried out to clarify the effects of antifungal Streptomyces sp. isolated from the soil grown kiwifruit on the growth inhibition of fruit rot (Botryosphaeria dothidea) infected in kiwi fruit plants in the southwestern districts of Jeonnam. Two hundred and fifty microorganisms were isolated and examined into the antifungal activity against Botryosphaeria dothidea. We screened and isolated six bacterial strains which have a strong inhibition against Botryosphaeria dothidea. And the best antifungal strain designated as the strain #120 showing 96.0% antifungal activity against Botryosphaeria dothidea was finally selected. The strain #120 was identified as Streptomyces sp. #120 based on its morphological, physiological, biochemical and chemotaxonomic characteristics.

• Journal of the Korean Wood Science and Technology
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• v.23 no.4
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• pp.108-116
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• 1995

This experiment was conducted to screen a superior wood-rotting fungi for lignin degradation and ligninolytic enzyme production by evaluation of red colored zone width on potato-dextrose agar medium and oak woodmeal medium complimented guaiacol. Relationship between the red colored zone width on GU-WA medium and klason lignin loss on woodmeal medium showed the positive correlation. Thus, the potential ligninolytic activity of wood rotting fungi which are not elucidated yet may be estimated to some extent by the evaluation of the red colored zone width on GU-WA medium. Of the isolates screened from fruit bodies and decayed woods. LKY-12, LKY-7 and C. versicolor-13 isolates having preferential lignin degradation and laccase activity were selected. These isolates exhibited characteristics of superior wood-rotting fungi as Klason lignin loss ranged from 30% to 35% and ligninolytic enzyme activity of these isolates on glucose-peptone broth was higher than that of other isolates. And then, these isolates were considered to be able to use in biological pulping and bleaching and ligninolytic enzyme production.

• Applied Biological Chemistry
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• v.40 no.5
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• pp.369-374
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• 1997

An endochitosanase-producing bacterium was isolated from soil and identified as a strain of Bacillus sp. The isolate was gram positive, rod shape $(0.4-0.6{\times}1.6-2.2{\mu}m)$, endospore-forming, catalase positive, and mobility positive, and grown at pH 4.5-11.0 and upto $42^{\circ}C$ in the medium containing 2% NaCl. RAPD analysis of the DNA purified from the strain was also performed, and the chitosanase-producing strain was named as Bacillus sp. P16. The culture supernatant of the strain showed strong liquefaction activity and rapidly decreased viscosity of chitosan solution. By TLC and HPLC, chitooligosaccharides of DP 2-7 were separated and identified from the enzyme hydrolyzates of chitosan. The chitosanase from Bacillus sp. P16 was thus regarded as an endo-splitting type.

• Applied Biological Chemistry
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• v.28 no.3
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• pp.149-155
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• 1985

590 strains of Rhizobia were isolated from root nodules of the legumes collected at 223 sites in Korea. According to their host specificities they were classified into R. japonicum(218 strains), R. phaseoli(101 strains), R. trifolii(97 strains), R. meliloti(4 strains), R. leguminosarium(1 strain), Rhizobium species(101 strains), and unidentified species(159 strains). 3 potent strains R-138, R-168, and R-214 of R. japonicum have been selected based on the infectivity to soybean cultivar and effeciency of nitrogen fixation. It was observed that the fast-growing strains of R. japonicum contained 1 to 4 plasmids of M.W. of 35-300 Md. However, plasmids were hardly detected for the slow-growing strains.

• Applied Biological Chemistry
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• v.26 no.2
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• pp.119-124
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• 1983

To investigate the possibility of ethanol production from jerusalem artichoke tubers (Helianthus tuberosus L.), various yeast strains were evaluated for their potential in metabolizing carbohydrate from jerusalem artichoke tubers to ethanol. Among them, Kluyveromyces fragilis CBS 1555 showed the highest inulase activity and ethanol fermentability. On the batch kinetic analysis, K. fragilis also showed the highest in parameters for ethanol production and substrate utilization, although lower than Saccharomyces cerevisiae Y-10 in cell mass yield and ethanol production yield.

• Current Research on Agriculture and Life Sciences
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• v.5
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• pp.119-126
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• 1987

This study was conducted to elucidate the most appropriate method to obtain auxotrophic mutants from Valsa ceratosperma, the causal fungus of apple canker, which may be used as a gene marker in detecting the transfer of the factors of avirulent strains to virulent strains. Among the 3 kinds of synthetic media tested, each have two formula for minimal and complete, the medium which has been used in study of Endothia parasitica (E. P medium) was turned out to be most appropriate for the growth of V. ceratosperma. A medium for single colony formation from pycnidiospore of this fungus was developed by adding 0.5% L - sorbose to the E. P minimal medium. The period of incubation in dark for preventing the photoreactivation after U. V irradiation was estimated as about 60hrs at which most of the spores become binucleate. Largest number of putative auxotrophs were obtained at about 50second of irradiation to the spores smeared on the medium for single colony formation, at which the survival rate of spores was 5 to 6 percent. With these method developed in this experiment, 161 isolates of putative auxotrophs were detected among which the nutrient requirement for 10 isolates were determined. Five out of 10 mutants were still virulent to apple tree and all but one could not sporulate.

• Korean Journal of Soil Science and Fertilizer
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• v.19 no.4
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• pp.345-350
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• 1986

In order to select suitable strains for utilization as soybean inoculants, the affinity between Rhizobium japonicum strains isolated from the domestic field and the several soybean varieties being distributed as recommended species was investigated by cross-inoculation experiments. The results obtained are as follows: 1. Rhizobium japonicum R-214 and R-138 showed broad affinity range to varies soybean species in terms of the nodule forming ability, the nitrogen fixing activity and the amount of total nitrogen absorption. In contrast, Rhizobium japonicum R-224 showed very low affinity to the same soybean groups. 2. The affinity of Hwang-Keum Kong and Jang-Paeck Kong to the rhizobium strains was the most signigicant, and that of Jang-Yeop Kong, Dong-Buk Tae, Paeck-Woon Kong and Dan-Yeop Kong was also significant. On the other hand, Pang-Sa Kong showed low affinity to the strains. 3. In general, the strains having high nitrogen-fixing activity seemed to possess the broad affinity range to the soybean hosts.