• Korean Journal of Microbiology
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• v.38 no.4
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• pp.293-298
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• 2002

In order to investigate the ecological aspect of bacteria on groundwater, water samples were collected from various regions. Total of 318 strains were isolated from diluted nutrient broth (DNB) agar medium, and investigated their growth pattern on nutrient broth (NB) medium. As a result, all the isolated strains were divided into two groups, NB and DNB organisms. Growth of DNB organisms were suppressed in full strength NB medium but not in DNB medium, which were called oligotrophic bacteria in this study. Proportion of DNB organisms occurred in the frequency of 50-98% in potable groundwaters (CW, CJ, DPG, CJG1), however, it was 23,46% in polluted site (TJ, NPG1). One hundred and two strains were identified as oligotrophic bacteria and their phylogenetic characteristics were determined by using 16S rDNA sequencing. Based on the phylogenetic analysis, they were found to fall into three major phylogenetic groups: belonging to the Proteobacteria $\alpha$-(49 strains), $\beta$-(50 strains), $\gamma$ -(3 strains) subdivisions. The phylogenetic analysis suggested that microbial diversity of potable groundwater is more complex than that obtained in the past investigation.

• Korean Journal of Microbiology
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• v.39 no.1
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• pp.16-20
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• 2003

A phylogenetic analysis of bacterial populations inhabiting soil derived from serpentine was conducted. The samples were collected from adjacent metamorphic rocks and serpentinite soil at Kwangcheon. The pH of the serpentine areas ranged from 8.5 to 9.2. The number of bacteria on the DAL medium which was diluted with $10^{-2}$ of AL medium was 10~100 fold higher than that from the full strength of AL medium, and which indicates that oligotrophs are distributed in the serpentinite soil. Of a total of 76 isolates, 42 isolates were oligotrophic bacteria, which grew only on the DAL medium. Based on a phylogenetic analysis using 16S rDNA sequences, these isolates are found to fall within five major phylogenetic groups: proteobacteria $\alpha$-subdivision (3 strains), $\alpha$-subdivision (7 strains), $\gamma$-subdivision (2 trains); high G+C gram-positive bacteria (19 strains); low G+C grampositive bacteria (14 strains). Bacteria of the genus Streptomyces (high G+C division) and Bacillus (low G+C division) have been considered to form a numerically important fraction of serpentinite soil. Oligotrophic strains categorized as Afipia ($\alpha$-subdivision), Ralstonia, Variovorax ($\beta$-subdivision), Pseudomonas ($\gamma$ -subdivision), Arthrobacter (high G+C division), and Streptomyces (low G+C division).

• Proceedings of the Microbiological Society of Korea Conference
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• 2002.10a
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• pp.15-21
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• 2002

Terminal-restriction fragment length polymorphism (T-RFLP) analysis has been optimized by using in vitro model community composed of genomic DNAs of known bacterial strains and has been applied to assess the bacterial community structure in marine sediments. The specific fluorescence-labeled terminal restriction fragments (T-RFs) between 39 and 839 base long specifying each strain were precisely measured for known bacterial strains. The addition of a co-solvent (dimethylsulfoxide or glycerol) into PCR reactions has reduced differential PCR amplification. Comparative bacterial community structure was investigated for pristine and polluted sediments. A complex T-RFLP pattern showing complex bacterial community structure was obtained in the pristine sediment, whereas simple T-RFLP pattern (low bacterial diversity) was shown in polluted sediments where caged aquaculture has been conducted for several years. The results of T-RFLP analysis were compared with that of cloning and sequencing 16S rDNA clones from the same sediments. Sequence analysis of 16S rDNA clones (72) of the pristine sediment revealed a diverse collection of lineages, largely of the class Proteobacteria ($6\%$ alpha subdivision, $46\%$ gamma subdivision, $13\%$ delta subdivision, and $3\%$ epsilon subdivision), Nitrospina $(8\%)$, high G+C gram positive $(8\%)$, Verrucomicrobia $(7\%)$, and Planctomycetes $(6\%)$. In the contaminated sediments, 17 $(59\%)$ of the 16S rDNA clones (29) were related to Campylobacter and symbiont of Rimicaris exoculata belonging to epsilon subdivision of Proteobacteria. The results obtained indicated that T-RFLP analysis is a rapid and precise technique for comparative bacterial community analysis.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.1
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• pp.67-74
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• 2004

A bacterium which grow on phenol as an only carbon and energy source was isolated from the sewage sludge at Nangi municipal wastewater treatment plant in Seoul. This bacterium was found to be a Gram negative rod with high motility, and well grew on 0.05%, 0.1%, and 0.15% of phenol. No matching strain was found from the result of the BBL test. Phylogenetic analysis of the strain by comparison of the 16s-rDNA has revealed that this bacterium has 99% of similarity with Stenotrophomonas maltophilia strain of Xanthomonas group, which belongs t the Gamma (${\gamma}$) subdivision of Proteobacteria. This strain has also shown 98% of similarity with nitrogen fixing bacterium MAGDE3 and Pseudomonas cissicola strain, and 97% of similarity with Stenotrophomonas sp. LMG198 and Xanthomonas cucurbitae.

• Journal of Microbiology
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• v.37 no.4
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• pp.193-199
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• 1999

Fifty-eight strains showing different colony morphological characteristics on various media were isolated from marine coral (Plexauridae sp.) and ambient seawater near Mun-Sum, Cheju-Island in 1998. Bacterial diversity was studies by phylogenetic analysis of the partial 16S rRNA gene sequences. All isolates representing the bacterial domain included affiliates of the high G+C (59%) and los G+C (3%) subdivision of Gram positive bacteria, and the alpha (33%) and gamma (5%) subdivision of the Proteobacteria. The 16S rDNA sequence similarity of the isolates was in the 88.3 to 100% range (average, 95.6%) to reported sequence data. In the comparison of the isolates from marine coarl and ambient seawater, more diverse groups belonging to ${\alpha}$-Proteobacteria were preferentially obtained from seawater.

• 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.

• Korean Journal of Microbiology
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• v.41 no.4
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• pp.293-299
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• 2005

Many isolates from soil of Korean ginseng rhizosphere did not show remarkable growth on full strength of the conventional nutrient broth (NB medium) but grew on its 100-fold dilution (DNB medium). Six hundred-forty strains were isolated as oligotrophic bacteria. In the course of screening for new bioactive compounds from oligotrophic bacteria from soil, 8 strains which had appeared to form of clear zone on a medium containing colloidal chitin as a sole carbon source were selected for further studies. Strain CR42 hydrolyzed a fluorogenic analogue of chitin, 4-methylumbelliferyl-D-glucosaminide (MUF-NAG) . Mo st of the culture supernatant of these isolates hydrolyzed 4-methylumbelliferyl-D-N,N'-diacetylchitobioside (MUF-diNAG). The isolates were heterogeneous and categorized to gamma- and beta-proteobacteria, Bacillaceae, Actinobactepia, and Bacteroides by 16S rRNA analysis. Two strains, WR164 and CR18, had a 16S rRNA sequence of $95-96\%$ identical to uncultured bacteria. It was observed that CR2 and CR75 could inhibit the growth of Colletotrichum gloeosporioides with hyphal extention-inhibition assay on PDA plate supplemented with $1\%$ colloidal chitin.

• Korean Journal of Microbiology
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• v.39 no.4
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• pp.260-266
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• 2003

In this study bacterial community was analyzed to evaluate the impacts of long-term use of agricultural chemicals on a soil ecosystem as well as to obtain fundamental data on the relationship. Sequences of 16S rRNA clones from a non-agricultural site and a tangerine orchard soil which has a history of long-term use of agricultural chemicals over 30 years were analyzed. This revealed that bacterial community containing 5 divisions and 18 genera was distributed in a tangerine orchard soil, while bacterial community containing 9 divisions and 44 genera was distributed. In a tangerine orchard soil site, the most abundant bacteria in subdivision level were placed into Proteobacteria γ group which occupied 56% of total clones. The other bacterial clones from the ocrhcard soil exposed to agricultural chemicals over 30 years were Acidobacteria group (25%), Fimicutes group (5%), Planctomycetes group (2%), Proteobacteria α (1%), δ group (1%), and Cyanobacteria group (1%). Whereas, the clones were from the non-agricultural site were distributed among the division or subdivision Acidobacteria group (14%), Planctomycetes group (13%), Proteobacteria α (10%), β (9%), δ (9%), Fimicutes group (8%), Verrucomicrobia group (8%), Actinobacteria group (6%), Proteobacteria γ group (3%), Bacteroidetes group (3%), Gemmatimonadetes group (3%), and Cyanobacteria group (1%). This finding suggests the possibility that long-term application of agricultural chemicals or fertilizers on a tangerine orchard might result in drastic reduction or alteration in the composition of the bacterial community in the contaminated soil site.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.8
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• pp.1126-1131
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• 2010

The antiobesity effect of soymilks fermented with Bacillus subtilis KC-3 (KCCM 42923) from cheonggukjang was compared with other sources of B. subtilis KCCM 11316 and B. subtilis MYCO. The antiobesity effect was investigated by measuring the release of leptin, Oil red O staining, glycerol secretions and adipogenic transcription factor by reverse transcription-polymerase chain reaction (RT-PCR) in the 3T3-L1 adipocytes. Fermented soymilk with B. subtilis KC-3 (F-KC) led to decrease levels of leptin secretion and increase levels of glycerol secretion in the cells. In addition, F-KC reduced contents of Oil red O dye in the 3T3-L1 adipocytes. Also, mRNA expression levels of both SREBP-1c (sterol regulatory element-binding protein 1-c) and PPAR-$\gamma$ (peroxisome proliferator-activated receptor-$\gamma$), which are adipogenic transcription factor, in cells treated with F-KC were markedly down regulated. These results demonstrate that the Bacillus subtillis fermented soymilk (F-KC) decreased lipid content in 3T3-L1 adipocytes by inhibiting lipogenesis. All B. subtilis fermented soymilks had shown antiobesity activities, however, F-KC exhibited the strongest antiobesity effect in the 3T3-L1 adipocytes. Our study suggests that especially F-KC increased the potential of antiobesity effects.

• Journal of Korean Library and Information Science Society
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• v.15
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• pp.179-205
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• 1988

The purpose of this research is to analyze the differences between electronical engineering class in KDC3 and electronical engineering class in DDC 19. The results of the study can be summarized as follows ; 1. The characteristics of the classification items in classification schemes of the electronical engineering fields is that KDC is classified by the vacuum tubes, electron tubes, special tubes, computers etc and DDC is classified by the microwave electronics, short-and long-wave electronics, X-ray and gamma-ray electronics, computers etc. 2. There is a blank in KDC and there are three blanks in DDC of the electronical engineering fields, but the total classification items number is much more in DDC than in KDC. This means that DDC is more classified than in the special classification items. 3. Classification items over 70% in the total classification items of computer fields in KDC, are classified a classification items of the short-and long-wave electronics in DDC. 4. There is a blank of computer fields in KDC and there are three blanks of computer fields in DDC, but the total classification items are many eighteen items. This means that DDC is more classified than KDC. 5. The sections of computers in DDC were established the 621.38195 classification item and the subsection of analogue computers in DDC were established the 621.381957 classification item and the subsection of digital computer in DDC were established the 621.381958 classification item. As we have seen, because of the development in technology and the subdivision of knowledge, the number of items is increased, and the terminology also become simplified and specified in the field of electronic engineering in KDC and DDC.