• Journal of Microbiology and Biotechnology
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• v.8 no.4
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• pp.310-317
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• 1998

Peptide synthetases are large multifunctional enzyme complexes that catalyze the nonribosomal synthesis of a structurally diverse family of peptide antibiotics. These enzymes are composed of functionally independent domains with independent enzymatic activities. Their specific linkage order of domains forms the protein template that defines the sequence of the incorporated amino acids. Within each domain, several motifs of highly conserved sequences have been identified from the sequence alignment of the various peptide synthetases ［30］. Taking advantage of the conserved nucleotide sequence of Core 1 and Core 2, we designed PCR primers to amplify the peptide synthetase genes from three different gram-positive bacterial strains. Nucleotide sequence analysis of the amplified PCR products from those three strains showed significant homology to various peptide synthetase genes, suggesting that the PCR products are parts of peptide synthetase genes. Therefore, this rapid and efficient PCR technique can be used for the isolation of peptide synthetase genes from various strains.

• Interdisciplinary Bio Central
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• v.2 no.4
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• pp.16.1-16.4
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• 2010

Cryopreservation of mouse embryos and spermatozoa has become the foremost technique for preserving large numbers of different strains of mice with induced mutations. In 1998, our mouse bank was established in the Center for Animal Resources and Development (CARD), Institute of Resource Development and Analysis, Kumamoto University, Japan, based on the Preservation, supply and development of genetically engineered animals report published by the Ministry of Education, Culture, Sports, Science and Technology. We cryopreserve mouse embryos and sperm, supply these resources, organize training courses to educate people and form part of a domestic and international network of both mutagenesis and resource centers. We currently have over 1,500 mouse strains, 842,000 frozen embryos and 26,000 straws containing frozen sperm. Moreover, we disclose information about 1,300 deposited strains. Furthermore, over 400 strains of frozen embryos or mice produced from frozen embryos and sperm are being supplied to the requesters both domestically and internationally. Additionally we hold training courses on the cryopreservation of mouse germplasm 2~3 times a year, both domestically and internationally. In the course, we teach basic reproductive engineering techniques to trainees on a man-to-man basis. We have already held 28 training courses on the cryopreservation of mouse germplasm at our center and at other institutes.

• Korean Journal of Microbiology
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• v.27 no.4
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• pp.415-421
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• 1989

Ten strains out of about 1,000 yeast strains isolated from byproducts of alcoholic industries, milk products, fruits, greens, food-related industries and soils of nature, revealed the killer activities. Two strains which have excellent killer activities among them were isolated and identified with Saccharomyces cerevisiae B 15-1 and Hansenula anomala Y 33 by investigation of the morphological, cultural and physiological properties. The optimal conditions on these strains for the production of killer toxin were investigated. The strain B 15-1 showed the highest killer toxin activities when it was cultured up to the log phase of 48 hr in YPD medium (pH 4.7) at $25^{\circ}C$. On the other hand, the strain Y33 revealed the highest activities when it was cultured up to the stationary phase of 60 hr in YPD medium (pH 4.0) at $20^{\circ}C$. The sensitive strain Kyokai 7 was found to be killed entirely by the killer toxin produced from the wild killer yeast B 15-1 when B 15-1 was cocultured with the same cell concentration ($10^{6}$ cells/ml) of Kyokai 7 after cultivation of 36 hr, and with large concentration ($9\times 10^{7}$ cells/ml) after 48 hr.

• Microbiology and Biotechnology Letters
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• v.48 no.2
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• pp.138-147
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• 2020

Various microorganisms play important roles in food fermentation, food spoilage, and agriculture. In this study, the biotype of 54 yeast and bacterial strains having high potential for utilization in food and agriculture, including Candida spp., Lactobacillus spp., and Acetobacter spp., were characterized by matrix-assisted laser desorption/ionization time-of flight mass spectrometry (MALDI-TOF MS). This characterization using a fast and robust method provides much-needed information on the selected microorganisms and will facilitate effective usage of these strains in various applications. Importantly, the unique protein profile of each microbial species obtained from this study was used to create a database of fingerprints from these species. The database was validated using microbial strains of the same species by comparing the mass spectra with the created database through pattern matching. The created reference database provides crucial information and is useful for further utilization of a large number of valuable microorganisms relevant to food and agriculture.

• Journal of the Optical Society of Korea
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• v.7 no.2
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• pp.106-112
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• 2003

In order to do continuous health monitoring of large structures, it is necessary that the distributed sensing of strain and temperature of the structures be measured. So, we present the temperature compensation of a signal from a fiber optic BOTDA (Brillouin Optical Time Domain Analysis) sensor. A fiber optic BOTDA sensor has good performance of strain measurement. However, the signal of a fiber optic BOTDA sensor is influenced by strain and temperature. Therefore, we applied an optical fiber on the beam as follows: one part of the fiber, which is sensitive to the strain and the temperature, is bonded on the surface of the beam and another part of the fiber, which is only sensitive to the temperature, is located nearby the strain sensing fiber. Therefore, the strains can be determined from the strain sensing fiber while compensating for the temperature from the temperature sensing fiber. These measured strains were compared with the strains from electrical strain gages. After temperature compensation, it was concluded that the strains from the fiber optic BOTDA sensor had good coincidence with those values of the conventional electrical strain gages.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.353-360
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• 2000

We developed large diameter sampler (we called KICT type large diameter sampler) to obtain undisturbed clay and sand samples. In-situ test carried out in the In-Chon international airport and Kim-Hae. Also we obtained undisturbed sample with a hydraulic piston sampler in the nearly site and carried out unconfined compression test, consolidation test and triaxial test. The result, unconfined compression strength, secant modules, preconsolidation pressure and undrained shear strength of samples to obtain KICT type large diameter sampler are larger than that of samples to obtain hydraulic piston sampler. But failure strains and volume changes at the consolidation of samples to obtain KICT type large diameter sampler are smaller than that of samples to obtain hydraulic piston sampler

• Applied Biological Chemistry
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• v.30 no.2
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• pp.163-168
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• 1987

A method, based upon the separation of cellular proteins by one-and two-dimensional electrophoresis was used for distinguishing butween Bradyrhizobium japonicum strains and Rhizobium fredii strains. Significant differences in protein pattern of one-dimensional SDS-PAGE vs-ere observed between Rhizobium fredii strains and Bradyrhizobium japonicum strains. The differences in six distinct main lands were observed among total 52 kinds of protein bands. Furthermore, the distribution of proteins in two groups by two-dimensional polyacrylamide gel electrophoresis was very different. The majority of visible proteins of Rhizobium fredii were acidic, whereas those of Bradyrhizobium japonicum were basic. In addition, amino acid composition was analyzed to detect the differences between two groups. No significant differences in amino acid composition were observed between Bradyrhizobium japonicum strains and Rhizobium fredii strains. The results indicate that one-and two-dimensional polyacrylamide gel electrophoresis were useful for identifying rhizobia isolates. One-dimensional SDS-PAGE of rhizobia proteins provided a rapid method for screening a large number of isolates, whereas two-dimensional electrophoresis was more of resolution and easiness for analyzing protein spots.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2000.04a
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• pp.150-156
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• 2000

Oligotrophic bacteria isolated from forest soil showed a specific community consisting of various taxonomic groups compared with those in other soil or aquatic habitats. Based on the cell shape, the isolates were divided into four groups: regular rod, curved/spiral rod, irregular rod, and prosthecate bacteria. The cellular fatty acids 60 oligotrophic isolates were analyzed. The 30 fatty acids which were identified or characterized are classified. At the dendrogram based on cellular fatty acid composition, four clusters(I-IV) were separated at a euclidian distance of about 50. Cluster 3 and 4-a strains were containing Q-8, these strains are accommodated in the Proteobacteria gamma and beta subdivision. The chemotaxonomic profiles of the cluster 4-a strains showed good agreement with those of the genus Burkholderia. Cluster 3 was characterized by the presence of branched-chain fatty acids, iso-C15:0, iso-C17:1, and iso-C17:0 as the major components. These chemotaxonomy suggested the close relationship of the isolates with Xathomonas/Sterotrophomonas group. Based on the 16S rDNA sequence analysis, the two representative strains(MH256 and MA828) of cluster 3 showed the close relation to genera, Xathomonas/Sterotrophomonas, but were not included in these genera. These strains were even further away from core Xanthomonas, and clearly were seen to branch outside the cluster formed by the Sterotrophomonas maltophilia. MH256 and MA828 16S rDNA sequence was different enough to put new genus on a separate branch. The isolates with Q-10 were also studied. They are corresponded to the two large groups in Proteobacteria alpha subdivision. One was incorporated in the genus Bradyrhizobium cluster, which also includes Agromonas, a genus for oligotrophic bacteria. The strains of the other group showed high similarity to the genus Agrobacterium.

• Applied Biological Chemistry
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• v.29 no.1
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• pp.3-9
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• 1986

A yeast strains, CJ 2, CJ 7 and CJ 8, isolated from soil and contaminated choose, mated with authentic strains of Saccharomycopsis lipolytica and were identified as Saccharomycopsis lipolytica with mating A, B and B, respectively. The strain CJ 7 produced large amount of isocitric acid in glucose and n-hexadecane medium as compared with another strains. All strains produced larger amount of citric acid in n-hexadecane medium as compared with glucose medium, and citric acid production of diploids was greater than that of the parental haploid strains. The specific activity of isocitrate lyase in n-hexadecane grown cells was $15{\sim}20$ times greater than that in glucose-grown cells, but the specific activity of citrate synthetase was not so influenced by carbon source. Little correlation between citric acid production and the specific acitivity of these enzymes was noticed irrespective of strains and ploidy.

• The Korean Journal of Mycology
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• v.52 no.2
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• pp.145-153
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• 2024

While investigation of the fungal diseases on apples collected from Cheongsong-gun and Bonghwa-gun in Gyeongbuk province, Korea, between August and September 2023 isolated five fungal strains from fruits with sooty blotch and flyspeck (SBFS) disease. The strains were designated as KNUF-23-CS02, KNUF-23-CS-06, KNUF-23-CS12, KNUF-23-BH01, and KNUF-23-BH03. When grown on potato dextrose agar and 2% water agar, the cultural characteristics of the strains were similar to those previously reported characteristics of Peltaster fructicola Pf001. The strains produced monoblastic, hyaline conidiogenous cells; the conidia were hyaline, unicellular, cylindrical to ovoidal, and 3.5-7×1.7-3.9 and 4.0-6.6×1.8-3.2 μm in size on synthetic nutrient-poor agar or water agars, respectively. Secondary conidia production by microcyclic conidiation and budding was observed. The KNUF-23-BH03 strain was shown to cause SBFS symptoms similar to those observed on the apples in the pathogenicity test. Molecular phylogenetic analyses were conducted based on the isolated species sequences of the internal transcribed spacer region, nuclear large ribosomal DNA subunit, and mitochondrial small ribosomal RNA subunit gene. The five strains were clustered with Peltaster fructicola Pf001. Based on the cultural and morphological characteristics and phylogenetic analysis, the five strains were identified as Peltaster fructicola, which has not been previously reported in Korea.