• Korean Journal of Microbiology
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• v.46 no.3
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• pp.296-302
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• 2010

Microcystis (Cyanobacteria, Chroococcales) is one of the green tide-causing organisms in freshwaters, and some species produce microcystin that is hepatotoxin. In the aspects of freshwater quality controls and health concerns, therefore it is necessary to manage the harmful organisms. In the present study, RNA polymerase beta subunit (rpoB) gene sequences of Microcystis were determined and characterized in order to use a potential marker for the molecular detections of the species. Microcystis rpoB showed high divergences of DNA similarity and genetic distances when compared with those of 16S rRNA, and the molecular differences were statistically significant (Student t-test, p<0.05). Parsimony analyses showed the rpoB gene evolves more than 2-fold faster than 16S rRNA. In addition, phylogeny of the rpoB gene separated each M. aeruginosa strain more clearly compared with a 16S rRNA tree. This study found that the order Chroococcales, including Microcystis, has approximately two rRNA operons and single copy of the rpoB gene in their chromosomes. These results suggest that the rpoB gene is a useful marker for the molecular phylogenetics and the detection of Microcystis.

• Korean Journal of Microbiology
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• v.38 no.2
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• pp.107-112
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• 2002

To isolate the bacteria lysing cyanobacteria, the sediment samples were collected from Dochang and Pal'tang Reservoir and Seokchon Lake. Each sample was smeared on the Anabaena cylindrica lawn and incubated in light chamber for 11 days. Bacteria having cyanobacteria-Iysing activity were isolated from the samples of Seokchon reservoir. Confirmation of cyanobacteria-Iysing activity was carried out to measure chlorophyll a and bacterial cell counting in mixed culture of Anabaena cylindrica and bacteria. Lysis was detected when extracellular meterials was added to the Anabaena cylindrica culture. The isolate was identified by analysis based on 16S rDNA sequence and morphological and physiological properties. The bacterial strain was taxonomically studied by the phylogenetic analysis based on 165 rDNA sequence. This strain was identified as a member of the genus Bacillus and designated as Bacillus sp. CHS1.

• Microbiology and Biotechnology Letters
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• v.42 no.3
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• pp.302-306
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• 2014

Ehwa nuruk (EN), a traditional Korean alcoholic rice beverage, is manufactured from pulverized wet rice and the needles of pine trees. In this study, the ethanol extract of EN and its subsequent organic solvent fractions were prepared, and their in-vitro anti-thrombosis activity evaluated. In an anti-coagulation assay, only the ethylacetate (EA) fraction of the ethanol extract showed significant extensions of thrombin time, prothrombin time and activated partial thromboplastin time. In a platelet aggregation assay, the water residue of the ethanol extract exhibited aggregation inhibitory activity. Our results suggest that the EA fraction has potential as a new anticoagulation agent and EN could be used as a novel resource for anti-thrombosis agents. This report provides the first evidence of the anti-thrombosis activity of EN.

• Microbiology and Biotechnology Letters
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• v.43 no.4
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• pp.373-377
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• 2015

The mature fruit of Sorbus commixta is known as magaja in Korea and is consumed in the form of tea and wine. In addition, it has been used to treat hypertension and articular neuralgia in folk medicine. In this study, the ethanol extract of magaja and its subsequent organic solvent fractions were prepared, and their in vitro anti-coagulation, and platelet aggregation inhibitory activities were evaluated. Among the fractions, the ethylacetate fraction demonstrated significant inhibition against thrombin, prothrombin, blood coagulation factors and platelet aggregation, without hemolysis activity up to 0.5 mg/ml. Our results suggest that the ethylacetate fraction of magaja has the potential to be used as a new anti-coagulation agent.

• Microbiology and Biotechnology Letters
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• v.38 no.2
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• pp.136-143
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• 2010

DNA fragments encoding the ketosynthase (KS) domain of polyketide synthase (PKS) genes were amplified using polymerase chain reaction (PCR) from 9 strains of Sorangium cellulosum isolated in Korea, cloned into a plasmid vector and sequenced. A total of 83 cloned DNA fragments were analyzed, and similar fragments were excluded, leaving 43 independent DNA fragments encoding the KS domains. The predicted amino acid sequences of 32 fragments were 70%-100% identical to the amino acid sequences of already known PKS genes, while the remaining 11 fragments were $\leq$67% or less identical to the known sequences, suggesting that these genes are novel PKS genes.

• The Journal of the Korean Society for Microbiology
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• v.22 no.3
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• pp.197-208
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• 1987

Chlamydia trachomatis has now shown that this interesting intracellular parasite is a cause of nongonococcal urethritis, infantile pneumonia, pelvic inflammatory disease and epididymitis, in addition to lymphogranuloma venerum and inclusion conjunctivitis. There are several diagnostic methods for C. trachomatis, but the method using monoclonal antibody is the most sensitive and specific. The hybride cell were prepared by fusion of myeloma cell($P_3X_{63}\;Ag_8{\cdot}V_{653}$) of mouse and lymphocyte of mouse(BALB/c) that were immunized with formalin killed C. trachomatis serotype D. The cell mixtures after fusion were dispensed into 640 wells of the 96 well culture plates and continuously cultured in HAT medium for 2 weeks. The supernatants of culture media in 83(13%) wells were reacted with C. trachomatis, which were determined by enzyme-linked immunosorbent assay in 96 well microplate. The clones that secreted antibody to C. trachomatis were cloned by limiting dilution. Only six monoclones secreted antibody to C. trachomatis. The antibody titer of ascitic fluid that collected from same BALB/c mice bearing hybridoma cells was above 1:100,000. These monoclonal antibodies that were IgG reacted with elementary and reticulate bodies of all serotypes(Ba, D, E, F, G, H, J and LGV type-I) using ELISA and indirect immunofluorescence stain, but there were no cross reaction with other bacteria(coagulase negative Staphylococcus, Proteus and E. coli). We concluded these six monoclones secreted the same monoclonal antibody to C. trachomatis. The sensitivity and specificity of the monoclonal antibody compared with Microtrak(confirmatory test of C. trachomatis, Syva) was 100%, respectively.

• Microbiology and Biotechnology Letters
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• v.47 no.1
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• pp.20-24
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• 2019

Moringa oleifera Lam (MOL) has been used as a traditional medicine to treat various cancers and inflammation. Whereas the bioactivities of the MOL leaf and seed are well reported, the study of the root is still rudimentary. In this study, the ethanol extract of MOL (EEMOL) and its subsequent organic solvent fractions were prepared and their anticoagulation activity in vitro and platelet aggregation inhibitory activity were evaluated. The EEMOL had negligible anticoagulation and strong platelet aggregation activities. However, the hexane and ethyl acetate fractions of EEMOL showed significant inhibition against thrombin, prothrombin, coagulation factors, and platelet aggregation, without hemolytic activity up to 1.0 mg/ml. Our results suggest that the active fractions of MOL root have potential as new anti-thrombosis agents.

• Research in Plant Disease
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• v.30 no.2
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• pp.103-113
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• 2024

Since 2009, the Korean Society of Plant Pathology has established the Committee on Common Names of Plant Disease to systematically review and determine plant disease names and related terminologies. The committee published the 6th edition of the List of Plant Diseases in Korea (LPDK) in 2022, and the list has been made publicly accessible online. The online database has significantly enhanced user accessibility, expedited update processes, and improved interoperability with other databases. As a result, the 6.1 edition of the list was released by online LPDK in 2023, detailing new disease names added over the preceding year and revisions to existing names. Subsequently, in 2024, the 6.2 edition was published, encompassing 6,765 diseases caused by 2,503 pathogen taxa across 1,432 host species. The public release of the online database has, however, introduced several challenges and tasks. Addressing these issues necessitates the development of modern, standardized nomenclature guidelines and a robust system for the registration of new disease names. Open communication and collaboration among the diverse members of the Korean Society of Plant Pathology are required to ensure the reliability of the LPDK.

• Journal of Life Science
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• v.26 no.1
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• pp.68-74
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• 2016

Perchlorate (ClO₄⁻) is an emerging pollutant detected in surface water, soil, and groundwater. Previous studies provided experimental evidence of autotrophic ClO₄⁻ removal with elemental sulfur (S⁰) particles and activated sludge, which are inexpensive and easily available, respectively. In addition, ClO₄⁻ removal efficiency was shown to increase when an enrichment culture was used as an inoculum instead of activated sludge. PCR-DGGE was employed in the present study to investigate the microbial community in the enrichment culture that removed ClO₄⁻ autotrophically. Microorganisms in the enrichment culture showed 99.71% or more ClO₄⁻ removal efficiency after a 7-day incubation when the initial concentration was approximately 120 mg ClO₄⁻/l. Genomic DNA was isolated from the enriched culture and its inoculum (activated sludge), and used for PCR-DGGE analysis of 16S rRNA genes. Microbial compositions of the enrichment culture and the activated sludge were different, as determined by their different DGGE profiles. The difference in DGGE banding patterns suggests that environmental conditions of the enrichment culture caused a change in the microbial community composition of the inoculated activated sludge. Dominant DGGE bands in the enrichment culture sample were affiliated with the classes β-Proteobacteria, Bacteroidetes, and Spirochaetes. Further investigation is warranted to reveal the metabolic roles of the dominant populations in the ClO₄⁻ degradation process, along with their isolation.

• Korean Journal of Environmental Biology
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• v.20 no.1
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• pp.20-24
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• 2002

We have from water samples of Kwalim, Dochang, and Mulwang reservoirs in Kyonggi-Do, where cyanobacteria blooming occurred. Isolated microbes which have lytic activity for cyanobacteria. Water samples were smeared on the Anabaena cylindrica lawn and incubated in light chamber at $28^\circ{C}$, under 3000 lux for 13 days. A fungus having cyanobacterial lytic activity was isolated from the samples of Dochang reservoir. The isolate was identified as Cryptococcus laurentii by Vitek system. From the culture of the isolate, four major extracellular protein bands (29, 35.2, 40.9, 51.1 kDa) have been detected and the 29 kDa protein band was more thickly appeared in the culture with cyanobacteria.