• The Plant Pathology Journal
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• 제16권4호
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• pp.189-199
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• 2000

To search for the antifungal substances, various actino-mycete isolates were obtained from various soils of Korea using plate dilution method on the humic acid vitamin agar plates. In the screening procedures using a dual culture method, 32 actionomycete isolates were selected, which showed the inhibitory activity against mycelial growth of plant pathogenic fungi Altirnaria mali, Colletotrichum gloeosporides, Fusarium oxysporum f.sp. cucumerinum, Magnaporthe grisea, Phytophthora capsici, and Rhizoctonia solani. Bioassay of the crude extracts from culture filtrates and mycelial mets revealed that 12 antagonistic actionomycetes produced highly active antifungal substances. Actinomycete strain S5-55 which showed the substantial antifungal activity against the tested fungi was selected for production of the antifungal substances. Based on the cytochemical and morphological characteristics, strain S5-55 was identified as a Streptomyces species. The results of the numerical identification using the TAXON program confirmed that Streptomyces strain S5-55 was identical with Streptomyces humidus including in TAXON major cluster 19. The production of antifungal substance was most favorable when S. humidus strain S5-55 was cultivated for 10 dats on soluble starch broth supplemented with $K_2$HPO$_4$. The antifungal substances active against the plant pathogenic fungi P. capsici and M. grisea were partially purified using $\textrm{C}_{18}$ reversed-phase column chromatography.

• 약학회지
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• 제40권6호
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• pp.713-719
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• 1996

Identification of soil microorganism strain B-6. a producer of acyl CoA synthetase inhibitor, based on its morphological, physiological, biochemical and chemotaxonomical charact eristics was performed. The strain B-6 was identified as Bacillus subtilis. Ihe acyl CoA synthetase inhibitor produced by this strain was highly achieved in fermentation medium that contained glucose 1.0%, soluble starch 1.0%, NH$_4$Cl 0.3%, oatmeal 1.0%, pharmamedia 1.0%, basic magnesium carbonate 0.5%. pH 7.5 at 30$^{\circ}$C for 7 days. The optimal pH and temperature for growth were 9.0 and 30$^{\circ}$C, respectively. Butanol extract of culture filterate of strain B-6 in acyl CoA synthetase inhibitor production medium containing corn steep liquor exhibited high acyl CoA synthetase inhibitor activity and antimicrobial activity against C. albicans. But chloroform extract of culture filterate of strain B-6 in medium containing NH$_4$Cl, ($NH_4)_2SO_4$ or urea instead of corn steep liquor exhibited higher antimicrobial activity against C. albicans than that of butanol extract.

• 한국미생물·생명공학회지
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• 제23권3호
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• pp.304-310
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• 1995

A thermophilic bacterium producing the extracellular cellulase-free xylanase was isolated from soil and has been identified as Bacillus sp. The optimal growth temperature was 50$\circ$C and the optimal pH, 7.0. Under the optimal growth condition, maximal xylanase production was 2.2 units/ml in the flask culture. The enzyme production was induced by xylan and xylose, but was repressed by sucrose or trehalose. The partially purified xylanase was most active at 70$\circ$C. It was found that the enzyme was stable at 65$\circ$C for 10 hours with over 75% of the activity. The enzyme was most active at pH 7.0 and retained 90% of its maximum activity between pH 5.0 and pH 9.0 though Bacillus sp. was not grown on alkaline conditions (>pH 8.0). In addition, the activity of xylanase was over 60% at pH 10.0. At the ambient temperature, the enzyme was stable over a pH range of 5.0 to 9.0 for 10 h, indicating that the enzyme is thermostable and alkalotolerant. The activity of xylanase was completely inhibited by metal ions including Hg$^{2+}$ and Fe$^{2+}$, while EDTA, phenylmethylsulfonyl fluoride (PMSF), $\beta$-mercaptoethanol and SDS didn't affect its activity. The enzyme was also identified to exert no activity on carboxymethylcellulose, laminarin, galactomannan, and soluble starch.

• 한국미생물·생명공학회지
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• 제13권3호
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• pp.223-232
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• 1985

한국의 토양에서 분리한 균 중 bacterial $\alpha$-amylase에 저해효과가 있는 균주를 분리하여 DMC-47 균주라 명명하였고, 이 균주는 Streptomyces 속의 균임을 확인하였다. 이 균주를 옥수수 전분 배지에서 진탕 배양한 결과 4일후에 최대 저해 효과를 나타내었다. 이 균주가 생성한 저해물질은 bacterial $\alpha$-amylase, pancreatic $\alpha$-amylase, salivary $\alpha$-amylase, glucoamylase에 저해효과를 보였고, $\beta$-amylase 에는 저해효과가 없었다.

• 소음진동
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• 제9권6호
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• pp.1247-1258
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• 1999

This paper presents vibration control of a CD-ROM(compact disc-read only memory) drive feeding system consisting of a new type of CD-ROM mount using an electro-rheologocal(ER) fluid. Chemically treated starch particles and silicon oil are used for EF fluid, and its field-dependent yield stresses are experimentally distilled under both the shear and the flow modes. On the basis of the yield stress, an appropriate size of ER CD-ROM mount adapted to conventional feeding system is designed and manufactured. Vibration isolation performance of the proposed mount is evaluated in the frequency domain and compared with that of conventional rubber mount. The ER CD-ROM mount is then installed to the drive feeding system and the system equation of motion is derived. The skyhook controller is then incorporated with the fuzzy technique to improve the performance of ER CD-ROM mount. A set of fuzzy parameters and control rules are obtained from a relation between vertical displacement and pitching motion of the feedng system. Followingthe formulation of the fuzzy-skyhook controller, computer simulation is undertaken in order to evaluate vibration suppression of the CD-ROM drive feeding system subjected to various excitations.

• Journal of Plant Biotechnology
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• 제4권2호
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• pp.59-65
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• 2002

ADP-glucose pyrophosphorylase (AGPase) catalyzes the key regulatory step in starch biosynthesis. Two cDNA clones encoding AGPase subunits were isolated from the leaf cDNA library of Chinese cabbage (Brassica campestris L. spp. pekinensis). One was designated as BCAGPS for the small subunit and the other as BCAGPL for the large subunit. Both cDNAs have uninterrupted open reading frames deriving 57 kDa and 63 kDa polypeptides for BCAGPS and BCAGPL, respectively, which showed significant similarity to those of other dicot plants. Also, However, the deduced amino acid sequence of BCAGPL has a unique feature. That is, it contains two regions (Rl and R2) lacking in all other plant enzymes. This is the first report of BCAGPL containing Rl and R2 among plant large subunits as well as small subunits. From the genomic Southern analysis and BAC library screening, we inferred the genomic status of BCAGPS and BCAGPL gene.

• 한국미생물·생명공학회지
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• 제3권2호
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• pp.73-82
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• 1975

In the course of studies on the production of thermostable amylases by thermophilic actinomycetes isolated from soils the investigation was carried out on the production of $\alpha$-amylase by G-1011 strain which had presented the most remarkable $\alpha$-amylase formation ability among 128 amylolytic isolates. The results were as follows ： 1. Characteristics of G-1011 strain were compared with those descriptions of thermophilic actinomycetes given in Bergey's Manual. The strain was identical to these species of actinomycetes. The details of physiological properties of the strain luould he published in near future. 2. The optimum temperature for incubation of the cell growth of G-1011 strain and $\alpha$-amylase production by the strain was revealed to 5$0^{\circ}C$. 3. The effective medium for $\alpha$-amylase formation by the strain was consisted of 3.0%, soluble starch, 1.0%, peptone, 0.5%, yeast extract, 0.5%, NaCl, 0.1%, MgSO$_4$ㆍ7$H_2O$ 0.02%, $K_2$MPO$_4$and 0.002% FeSO$_4$ㆍ7$H_2O$. The pH of the medium was ajusted to 7.0 with phosphate buffer solution. 4. The maximum production of $\alpha$-amylase (3420 D. U/ml) by G-1011 strain resulted when it was grown for 16 hours with the culture of reciprocal shaking.

• Animal cells and systems
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• 제4권1호
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• pp.23-30
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• 2000

Horizontal starch gel electrophoresis for 29 populations (n=543) of the wrinkled frog, Rana rugosa, from Korea and Japan was peformed to assess the degree of genic variation and genetic diversity, and to understand the biogeographic pattern of distribution and speciation. A sum of 22 presumptive loci was screened from 17 enzymes and general proteins. Four loci, Aco, Est-3, Me-2, and Pgm, demonstrated high levels of polymorphism. The degree of average genetic variation of R. rugosa was P=22.7% (9.1-40.9%), Ho=0.086 (0.048-0.165) and He=0.090 (0.042-0.168). In the south-eastern region of the Korean peninsula (Chongsong, Yongchon, Ulsan, Kyongju, Pohang, yongdok and Ulchin), a few unique alleles in the Mpi locus were detected and their biogeographic implications were considered. The degree of genetic differentiation among the Korean populations was moderate (S=0.900), whereas the degree of genetic diversity between Korean and Japanese populations was notably high (S=0.687, D=0.293). This result corresponds with the data obtained by the mitochondrial cytochrome b gene sequence (Lee et al., 1999) suggesting that the Korean and Japanese R. rugosa might have evolved a specific level of genetic differentiation since their geographic isolation.

• Journal of Animal Science and Technology
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• 제48권1호
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• pp.77-90
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• 2006

본 연구는 꽃사슴과 Holstein 젖소의 반추위와 대장에 서식하는 미생물중 섬유소 분해력이 강한 혐기성 박테리아를 순수 분리하여 분리된 미생물들을 동정하고 이들 미생물들의 효소 특성을 구명하고자 수행되었다. 배지의 종류에 관계없이 젖소에서 분리된 박테리아가 꽃사슴에서 분리된 미생물에 비하여 섬유소 분해효소 활력이 우수하였고 탄소 공급원의 종류에 의해 섬유소 분해 효소의 활력에 영향을 미쳤으며 특히, cellulose 단독 공급시 보다 starch, glucose와 cellobiose를 복합한 탄소 공급원을 제공시 일반적으로 높은 효소의 활력을 나타내었다. API kit를 이용한 생화학 및 당발효 시험 결과 알려진 강력한 섬유소 분해 박테리아는 동정되지 않았고 대부분의 박테리아가 Peptostreptococcus spp., Bifidobacterium spp., Prevotela ruminicola/buccae, Clostridium beijer/butyricum 및 Streptococcus intemedis로 동정되었다. 분리된 균들의 다당류 및 단당류를 분해할 수 있는 가수분해 효소인 Avicelase, xylanase, β-D-glucosidase, α-L-arabino- furanosidase 및 β-xylosidase의 효소활력은 이용하는 배지조성 특히 탄소 공급원의 종류에 의하여 효소의 활력에 영향을 미치며 가수분해 효소의 종류에 따라 각 분리된 균주들마다의 다른 분포를 나타내었다. 결론적으로 분리된 혐기성 박테리아들이 공급되는 탄수화물 기질의 종류에 따라 효소의 활력에 변화를 일으켰고 이것은 기질에 따른 박테리아의 효소생산 특이성과 성장률의 변화에서 기인하였기 때문이다.

• 한국균학회지
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• 제13권4호
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• pp.203-212
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• 1985

전국 각지 토양으로 부터 채취한 토양균을 screening하여 ${\alpha}-amylase$를 저해하는 물질을 생성하는 균주인 Streptomyces DMC-72를 선발하였다. 이 균주가 생성하는 저해제를 acetone 침전 및 이온 교환 수지인 Amberlite IRC-50, Amberlite CG-50과 SP-Sephadex C-25를 이용하여 분리하였다. 이 물질은 ${\alpha}-amylase$ 뿐만아니라 다른 amylase와 기타 효소에 대해서도 억제작용을 나타내었다. 이 물질은 기질인 soluble starch의 가수분해에 대해서 non-competitive하게 저해작용을 보이주고 있으며 열 및 넓은 범위의 pH에서 안정한 물질이었다. 이 물질은 anthrone 시험과 IR spectrum에 의해서 oligosaccharide계 화합물임을 알 수 있었다.