• Genomics & Informatics
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• v.10 no.2
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• pp.110-116
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• 2012

Recent several studies have shown that the genetic variation of SCN5A is related with atrioventricular conduction block (AVB); no study has yet been published in Koreans. Therefore, to determine the AVB-associated genetic variation in Korean patients, we investigated the genetic variation of SCN5A in Korean patients with AVB and compared with normal control subjects. We enrolled 113 patients with AVB and 80 normal controls with no cardiac symptoms. DNA was isolated from the peripheral blood, and all exons (exon 2-exon 28) except the untranslated region and exon-intron boundaries of the SCN5A gene were amplified by multiplex PCR and directly sequenced using an ABI PRISM 3100 Genetic Analyzer. When a variation was discovered in genomic DNA from AVB patients, we confirmed whether the same variation existed in the control genomic DNA. In the present study, a total of 7 genetic variations were detected in 113 AVB patients. Of the 7 variations, 5 (G87A-A29A, intervening sequence 9-3C>A, A1673G-H558R, G3578A-R1193Q, and T5457C-D1819D) have been reported in previous studies, and 2 (C48G-F16L and G3048A-T1016T) were novel variations that have not been reported. The 2 newly discovered variations were not found in the 80 normal controls. In addition, G298S, G514C, P1008S, G1406R, and D1595N, identified in other ethnic populations, were not detected in this study. We found 2 novel genetic variations in the SCN5A gene in Korean patients with AVB. However, further functional study might be needed.

• Mycobiology
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• v.44 no.4
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• pp.191-201
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• 2016

In this study, the phylogeny and morphology of Mycosphaerella nawae (Dothideomycetes, Ascomycota) were examined using Korean and Japanese isolates, to establish the phylogenetic relationship between M. nawae and its allied species. Korean and Japanese isolates of M. nawae were collected from circular leaf spot-diseased leaves and were confirmed based on internal transcribed spacer (ITS) sequence data. Phylogenetic analysis was conducted using multiple genes, including the ITS region, 28S rDNA, ${\beta}-tubulin$, translation elongation $factor-1{\alpha}$, and actin genes. Our results revealed that M. nawae is closely related to members of the genus Phaeophleospora but are distant from the Ramularia spp. In addition, microscopic analysis revealed pseudothecia on the adaxial and abaxial surface of overwintered diseased leaves (ODL) and only on the abaxial surface of diseased leaves. Ascospores are oval to fusiform, one-septate, tapered at both ends, $1.7{\sim}3.1{\times}8.1{\sim}14.1{\mu}m$, and were observed in ODL. Conidia are oval, guttulate, one-septate, $3.5{\sim}4.9{\times}12.8{\sim}19.8{\mu}m$, and barely discernable on 30-day cultures. To our knowledge, this is the first report on the phylogeny of M. nawae, which is closely related to the genus Phaeophleospora, especially P. scytalidii.

• Food Science of Animal Resources
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• v.28 no.1
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• pp.82-90
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• 2008

Two strains of pure lactic acid bacteria capable of forming both acid and slime were isolated from the kefir made of goat milk. The isolated strains observed by morphological and physiological properties, and their 16S rDNA partial sequence were identified as Streptococcus salivarius subsp. thermophilus(LFG-1) and Lactococcus lactis subsp. lacits(LFG-2) with over 99% homology. The optimum temperature of Str. salivarius subs. thermophilus LFG-1 for growth was $40-45^{\circ}C$, and its generation time was 40.6 minutes. The final pH of cultured broth by Str. salivarius subsp. thermophilus LFG-1 and the commercial strain Str. thermophilus Body-1 for 24hr at $37^{\circ}C$ were 4.30 and 4.55, respectively. The coagulative activity of Str. salivarius subsp. thermophilus LFG-1 was almost as strong as that of commercial strain Str. thermophilus Body-1. However, the LFG-2 strain showed lower coagulative activity than Str. thermophilus Body-1. The survival rate of lactic acid bacteria were between 22-29% in 0.3% bile extract. At pH 1.0 all of the bacteria were killed, and most of lactic acid bacteria died against pH 3.0. However, all lactic acid bacteria survived well at pH 4.5.

• Journal of Microbiology and Biotechnology
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• v.32 no.7
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• pp.855-861
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• 2022

A white-pigmented, non-motile, gram-negative, and rod-shaped bacterium, designated CYS-02^T, was isolated from soil sampled at Suwon, Gyeonggi-do, Republic of Korea. Cells were strictly aerobic, grew optimally at 20-28℃ and hydrolyzed Tween 40. Phylogenetic analysis based on 16S rRNA gene sequence indicated that strain CYS-02^T formed a lineage within the family Comamonadaceae and clustered as members of the genus Variovorax. The closest members were Variovorax guangxiensis DSM 27352^T (98.6% sequence similarity), Variovorax paradoxus NBRC 15149^T (98.5%), and Variovorax gossypii JM-310^T (98.3%). The principal respiratory quinone was Q-8 and the major polar lipids contain phosphatidylethanolamine (PE), phosphatidylethanolamine (PG), and diphosphatidylglycerol (DPG). The predominant cellular fatty acids were C_16:0, summed feature 3 (C_16:1ω7c and/or C_16:1ω6c) and summed feature 8 (C_18:1ω7c and/or C_18:1ω6c). The DNA GC content was 67.7 mol%. The ANI and dDDH values between strain CYS-02T and the closest members in the genus Variovorax were ≤ 79.0 and 22.4%, respectively, and the AAI and POCP values between CYS-02^T and the other related species in the family Comamonadaceae were > 70% and > 50%, respectively. The genome of strain CYS-02^T showed a putative terpene biosynthetic cluster responsible for antioxidant activity which was supported by DPPH radical scavenging activity test. Based on genomic, phenotypic and chemotaxonomic analyses, strain CYS-02^T was classified into a novel species in the genus Variovorax, for which the name Variovorax terrae sp. nov., has been proposed. The type strain is CYS-02^T (= KACC 22656^T = NBRC 00115645^T).

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1143-1149
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• 2003

To elucidate a method of preventing dental caries, strains producing lytic enzymes were isolated and their characteristics were investigated. Among 5,00 alkalophilic strains isolated from soil, 22 strains showed lytic activity against Streptococcus mutans. Strain No. 4830, with the highest lytic activity, was selected for further study. Strain 4830 showed 94% sequence homology with the 16S rDNA sequence of Bacillus alcalophilus, but it was concluded to be different from Bacillus alcalophilus because of its biochemical characteristics. The strain was named Bacillus sp. 4830. The lytic enzyme from Bacillus sp. 4830 was purified by ethanol precipitation and CM-agarose column chromatography. The molecular weight of the lytic enzyme was determined to be 28 kDa by SDS-PAGE. The lytic enzyme was stable between pH 5.0 and pH 11 and up to $40^{\circ}C$. The optimal pH and temperature for the lytic activity was 9.0 and $50^{\circ}C$, respectively.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.2
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• pp.128-136
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• 2006

This study was conducted for developing the stability parameter in uncontrolled landfill by using a biomolecular investigation on the microbial community growing through leachate plume. Landfill J(which is in Cheonan) and landfill T(which is in Wonju) were chosen for this study among a total of 244 closed uncontrolled landfills. It addressed the genetic diversity of the microbial community in the leachate by 165 rDNA gene cloning using PCR and compared quantitative analysis of denitrifiers and methanotrophs with the conventional water quality parameters. From the BLAST search, genes of 47.6% in landfill J, and 32.5% in landfill T, respectively, showed more than 97% of the similarity where Proteobacteria phylum was most significantly observed. It showed that the numbers of denitrification genes, i.e. nirS gene and cnorB gene in the J site are 7 and 4 times higher than those in T site, which is well reflecting from a difference of site closure showing 7 and 13 years after being closed, respectively. In addition, the quantitative analysis on methane formation gene showed that J1 spot immediately bordering with the sources has the greatest number of methane formation bacteria, and it was decreased rapidly according to distribute toward the outer boundary of landfill. The comparative investigation between the number of genes, i.e. nirS gene, cnorB gene and MCR gene, md the conventional monitoring parameters, i.e. TOC, $NH_3-N,\;NO_3-N,\;NO_2-N,\;Cl^-$, alkalinity, addressed that more than 99% of the correlation was observed except for the $NO_3-N$. It was concluded that biomolecular investigation was well consistent with the conventional monitoring parameters to interpret their influences and stability made by leachate plume formed in downgradient around the uncontrolled sites.

• The Korean Journal of Mycology
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• v.41 no.2
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• pp.67-73
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• 2013

Microbial diversity of soil samples from ancient stone-lined tombs was investigated. The tombs, discovered at Eoryung Ocheon-Ri site, Korea, were estimated to be belonged to middle class people from an ancient country, Gaya, which existed till AD 559 at the southern part of Korea. Nine fungal stains and 70 bacterial strains were isolated from the twelve soil samples, which were collected from the tomb Nos. 5 and 6. Ribosomal DNA sequence analysis discovered 5 fungal and 22 bacterial strains belonged to 10 genus groups from the tomb No. 5 while 1 fungal and 28 bacterial strains belonged to 6 genus from the tomb No. 6. The higher microbial diversity suggests that the tomb No. 5 was constructed warmer season than the tomb No. 6. Moreover, the discovery of Staphylococcus warneri, which is found as part of the skin flora on human and animals, and Bacillus aquimaris, which is a marine bacterium and can be discovered from tidal flat, from the surface of large dagger suggests that the ancient people may use meat and seafood at the burial ceremony.

• Korean Journal of Microbiology
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• v.48 no.4
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• pp.298-304
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• 2012

Among 63 Bacillus strains grown at $60^{\circ}C$ from sixteen samples of homemade Korean soybean paste, one strain was selected for producing the thermostable protease. The isolate has been identified as Bacillus licheniformis on the basis of its 16S rDNA sequence, morphology and biochemical properties. Culture filtrate of the isolate showed maximal protease activity at the reaction condition of $60-65^{\circ}C$ and pH 11. The culture filtrate retained more than 87% of initial protease activity after incubation for 30 min at $60^{\circ}C$ without substrate. In order to develop the medium composition, effects of ingredients including nitrogen sources, carbon sources, metal ions and phosphate were examined for protease production of the isolate. Lactose and soytone peptone were the most effective carbon and nitrogen source for the enzyme production. After the late logarithmic growth phase the isolate began to produce the protease, and the maximum protease productivity was reached to 550 unit/ml in the optimized medium consisting of lactose (3%), soytone peptone (1.5%), $MgSO_4$ (0.1%), $K_2HPO_4$ (0.03%), and $KH_2PO_4$ (0.03%) at 28 h of incubation.

• Korean Journal of Microbiology
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• v.53 no.4
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• pp.242-250
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• 2017

Actinobacteria tolerating extreme conditions can be a rich source of bioactive compounds and enzymes. In this study filamentous actinobacteria were isolated from soils of Ulleung Island, and their physiological properties were examined. Soil samples were collected, serially diluted and spread on various agar media. The average viable counts of total bacteria were $1.28{\times}10^7CFU/g$ for soil sample 1 (ULS1) and $2.05{\times}10^7CFU/g$ for soil sample 2 (ULS2). As a result, 34 strains of actinobacteria were isolated and assigned to the genera Streptomyces (16 strains), Isoptericola (5 strains), Rhodococcus (4 strains), Agromyces (3 strains), Micrococcus (2 strains), Arthrobacter (1 strain), Williamsia (1 strain), Microbacterium (1 strain), and Oerskovia (1 strain) based on 16S rRNA gene sequence analysis. Enzyme activity and plant growth promoting potential were tested for representative isolates. Multiple strains of Streptomyces degraded starch, casein and Tween 80. As for plant growth promoting potential, strains of Oerskovia, Williamsia, Isoptericola, and Streptomyces solubilized phosphate, and those of Agromyces, Oerskovia, Micrococcus, Rhodococcus, Streptomyces, and Isoptericola produced 3-indole-acetic acid (IAA), respectively. Selected strains of Streptomyces exhibited strong antagonistic activity against Staphylococcus aureus and Bacillus subtilis as well as Candida albicans. This study confirms that actinobacteria from Ulleung Island can be a good source of novel bioactive compounds.

• Microbiology and Biotechnology Letters
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• v.39 no.2
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• pp.133-139
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• 2011

In this study, we determined the changes in microbial numbers in solar salts according to the manufacturing process and storage duration. The salt samples were harvested from salt farms in Shinan (area 2) and Yeonggwang (area 1). They were serially diluted ten-fold and then placed on 4 kinds of cultivable media (mannitol salt agar, eosin methylene blue, plate count agar, and trypticase soy agar). After incubation, we obtained 62 halophilic isolates from the salt samples. Coliform and general bacteria were not detected in all salt samples. By 16S rRNA sequencing analysis, we found 12 kinds of halophilic bacteria belonging to the genera Halobacillus, Halomonas, Bacillus, Idiomarina, Marinobacter, Pseudoalteromonas, Vibrio, Salinivibrio, Virgibacillus, Alteromonas, Staphylococcus and some un-known stains. In our study, we discovered two novel species that have a 16S rDNA sequence similarity below 97%.