• Reproductive and Developmental Biology
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• v.39 no.4
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• pp.105-115
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• 2015

Toll-like receptor 7 (TLR7) is critical for the triggering of innate immune response by recognizing the conserved molecular patterns of single-stranded RNA (ssRNA) viruses and mediated antigenic adaptive immunity. To understand how TLR7 distinguish pathogen-derived molecular patterns from the host self, it is essential to be able to identify TLR7 receptor interaction interfaces, such as active sites or R848-agonist binding sites. The functional interfaces of TLR7 can serve as targets for structure-based drug design in studying the TLR7 receptor's structure-function relationship. In contrast to mammalian TLR7, chicken TLR7 (chTLR7) is unknown for its important biological function. Therefore, it has been targeted to mediate contrasting evolutionary patterns of positive selection into non-synonymous SNPs across eleven species using TLR7 conservation patterns (evolutionary conserved and class-specific trace residues), where protein sequence differences to the TLR7 receptors of interest record mutation that have passed positive section across the species. In this study, we characterized the Lys609 residue on chTLR7-ECD homodimer interfaces to reflect the current tendency of evolving positive selection to be transfer into a stabilization direction of the R848-agonist/chTLR7-ECDs complex under the phylogenetically variable position across species and we suggest a potential indicator for contrasting evolutionary patterns of both the species TLR-ECDs.

• Journal of Microbiology and Biotechnology
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• v.25 no.10
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• pp.1734-1741
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• 2015

Few research had investigated the secretion of phospholipase and aspartyl proteinase from Candida spp. causing infection in females with type 2 diabetes mellitus. This research aimed to investigate the prevalence of vulvovaginal candidiasis (VVC) in diabetic versus non-diabetic women and compare the ability of identified Candida isolates to secrete phospholipases and aspartyl proteinases with characterization of their genetic profile. The study included 80 females with type 2 diabetes mellitus and 100 non-diabetic females within the child-bearing period. Candida strains were isolated and identified by conventional microbiological methods and by API Candida. The isolates were screened for their extracellular phospholipase and proteinase activities by culturing them on egg yolk and bovine serum albumin media, respectively. Detection of aspartyl proteinase genes (SAP1 to SAP8) and phospholipase genes (PLB1, PLB2) were performed by multiplex polymerase chain reaction. Our results indicated that vaginal candidiasis was significantly higher among the diabetic group versus nondiabetic group (50% versus 20%, respectively) (p = 0.004). C. albicans was the most prevalent species followed by C. glabrata in both groups. No significant association between diabetes mellitus and phospholipase activities was detected (p = 0.262), whereas high significant proteinase activities exhibited by Candida isolated from diabetic females were found (82.5%) (p = 0.000). Non-significant associations between any of the tested proteinase or phospholipase genes and diabetes mellitus were detected (p > 0.05). In conclusion, it is noticed that the incidence of C. glabrata causing VVC is increased. The higher prevalence of vaginal candidiasis among diabetics could be related to the increased aspartyl proteinase production in this group of patients.

• Journal of Microbiology and Biotechnology
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• v.18 no.2
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• pp.383-391
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• 2008

The glycans linked to the insect cell-derived glycoproteins are known to differ from those expressed in mammalian cells, partly because of the low level or lack of glycosyltransferase activities. GnT II, GnT IV, GnT V, and ST3Gal IV, which play important roles in the synthesis of tetraantennarytype complex glycan structures in mammalian cells, were overexpressed in Trichoplusia ni cells by using a baculovirus expression vector. The glycosyltransferases, expressed as a fusion form with the IgG-binding domain, were secreted into the culture media and purified using IgG sepharose resin. The enzyme assay, performed using a pyridylaminated-sugar chain as an acceptor, indicated that the purified glycosyltransferases retained their enzyme activities. Human erythropoietin expressed in T. ni cells (rhEPO) was subjected to in vitro glycosylation by using recombinant glycosyltransferases and was converted into complex-type glycan with terminal sialic acid. The presence of Nacetylglucosamine, galactose, and sialic acid on the rhEPO moiety was detected by a lectin blot analysis, and the addition of galactose and sialic acid to rhEPO was confirmed by autoradiography using $UDP-^{14}C-Gal\;and\;CMP-^{14}C-Sia$ as donors. The in vitro glycosylated rhEPO was injected into mice, and the number of reticulocytes among the ed blood cells was counted using FACS. A significant increase in the number of reticulocytes was not observed in the mice injected with in vitro glycosylated rhEPO as compared with those injected with rhEPO.

• Journal of Microbiology and Biotechnology
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• v.12 no.1
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• pp.106-113
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• 2002

One-hundred and twenty-four trimethoprim-resistant Shigella sonnei isolates extracted in Korea during the last two decades were investigated for their epidemiological relationship and mechanisms of resistance to trimethoprim. The S. sonnei isolates were distributed into two groups by three different epidemiological tools: biotyping, antibiogram, and pulsed-field gel electrophoresis. One group contained the isolates from the 1980s and the other group included the isolates from the 1990s. The geometric mean MICs of trimethoprim in S. sonnei isolates from the 1980s and 1990s were found to be $672.9{\mu}g/ml\;and\;>2,048{\mu}g/ml$, respectively. Trimethoprim resistance was associated with dfrA5, dfrA12, and dfrA13 genes in the isolates from the 1980s, dfrA1, dfrA5, and dfrA12 in the isolates from 1991, and dfrA1 and dfrA12 in the isolates from 1992 to 1999. The dfrA1 gene was located downstream of the intI2 gene in Tn7, which was located on chromosome. Some dfrA12 genes were found as gene cassettes in the class 1 integron. The dfrA5 and dfrA13 genes were located on conjugative plasmids. These results suggested that a clonal change occurred in S. sonnei isolates in Korea during the last two decades and that dfr genes located on different transposable genetic elements had gradually changed.

• Microbiology and Biotechnology Letters
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• v.14 no.5
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• pp.359-363
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• 1986

S. diastaticus hydrolysised $\alpha$-1.4 linkage of the starch and was known fermenting yeast strain, but poorly hydrolized $\alpha$-1.6 linkage of the starch. To improve the starch fermentation ability of yeast, we tried that protoplast fusion between S. diastaticus and C. tropicalis and finally two starins of fusant (FPDC42, FPDC43) were obtained. C. tropicalis well hydrolysis both $\alpha$-1.4 and $\alpha$-1.6 linkanges in the starch. The protoplast of parental auxotrophic cells were fused in the presence of 10mM CaCl$_2$ and 35% of polyethylene glycol (M. W. 4,000). The fusion frequency was 10$^{-5}$ to 10$^{-6}$. Properties of the fusants(genetic stability, assimilation of carbon sources, random spore formation, copper resistance, NaCl tolerance, DNA content, cell size and growth rate) were investigated.

• Journal of Microbiology and Biotechnology
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• v.17 no.11
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• pp.1818-1825
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• 2007

S-Adenosylmethionine (SAM) was previously documented to activate secondary metabolism in a variety of Streptomyces spp. and to promote actinorhodin (ACT) and undecylprodigiosin (RED) in Streptomyces coelicolor. The SAM-induced proteins in S. coelicolor include several ABC transporter components (SCO5260 and SCO5477) including BldKB, the component of a well-known regulatory factor for differentiations. In order to assess the role of these ABC transporter complexes in differentiation of Streptomyces, SCO5260 and SCO5476, the first genes from the cognate complex clusters, were individually inactivated by gene replacement. Inactivation of either SCO5260 or SCO5476 led to impaired sporulation on agar medium, with the more drastic defect in the SCO5260 null mutant (${\Delta}SCO5260$). ${\Delta}SCO5260$ displayed growth retardation and reduced yields of ACT and RED in liquid cultures. In addition, SAM supplementation failed in promoting the production of ACT and RED in ${\Delta}SCO5260$. Inactivation of SCO5476 gave no significant change in growth and production of ACT and RED, but impaired the promoting effect of SAM on ACT production without interfering with the effect on RED production. The present study suggests that SAM induces several ABC transporters to modulate secondary metabolism and morphological development in S. coelicolor.

• Journal of Microbiology and Biotechnology
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• v.17 no.7
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• pp.1079-1082
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• 2007

Chromosome microdissection and the reverse FISH technique is one of the most useful methods for the identification of structurally abnormal chromosomes. In particular, the laser microbeam microdissection (LMM) method allows rapid isolation of a target chromosome or a specific region of chromosomes without damage of genetic materials and contamination. Isolated chromosomes were directly amplified by the degenerate oligonucleotide-primed polymerase chain reaction (DOP-PCR), and then the FISH probes labeled with spectrum green- or spectrum red-dUTP were generated by nick-translation. Whole chromosome painting (WCP) probes were successfully generated from only 5 copies of the chromosome. With this method, we produced 24 WCP probes for each human chromosome. We also tried to characterize a marker chromosome, which seemed to be originated from chromosome 11 on conventional banding technique. The marker chromosomes were isolated by the LMM method and analyzed by reverse FISH. We elucidated that the marker chromosome was originated from the short arm of chromosome 5 ($5p11{\to}pter$). A fully automated and computer-controlled LMM method is a very simple laboratory procedure, and enables rapid and precise characterization of various chromosome abnormalities.

• Journal of Microbiology and Biotechnology
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• v.21 no.10
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• pp.1021-1025
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• 2011

A Bacillus subtilis strain was isolated from the intestine of Sebastiscus marmoratus (scorpion fish) that was identified as Bacillus subtilis CH2 by morphological, biochemical, and genetic analyses. The chitosanase of Bacillus subtilis CH2 was best induced by fructose and not induced with chitosan, unlike other chitosanases. The strain was incubated in LB broth, and the chitosanase secreted into the medium was concentrated with ammonium sulfate precipitation and purified by gel permeation chromatography. The molecular mass of the purified chitosanase was detected as 29 kDa. The optimum pH and temperature of the purified chitosanase were 5.5 and $60^{\circ}C$, respectively. The purified chitosanase was continuously thermostable at $40^{\circ}C$. The specific acitivity of the purified chitosanase was 161 units/mg. The N-terminal amino acid sequence was analyzed for future study.

• Microbiology and Biotechnology Letters
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• v.45 no.3
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• pp.243-249
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• 2017

An agar-degrading bacterium, designated as the GNUM08123 strain, was isolated from samples of red algae collected from the Yongil Bay near East Sea, Korea. The isolated GNUM08123 strain was gram-negative, aerobic, motile, and beige-pigmented, with $C_{16:0}$ (25.9%) and summed feature 3 (comprising $C_{16:1}{\omega}7c/iso-C_{15:0}2-OH$, 34.4%) as its major cellular fatty acids. A similarity search based on the 16S rRNA gene sequence revealed that it belonged to class Gammaproteobacteria and shared 97.7% similarity with the type strain Vibrio chagasii $R-3712^T$. The DNA G+C content of strain $GNUM08123^T$ was 46.9 mol%. The major isoprenoid quinone was ubiquinone-8. The results of DNA-DNA relatedness and 16S rRNA sequence similarity analyses, in addition to its phenotypic and chemotaxonomic characteristics, suggest that strain GNUM08123 is a novel species within genus Vibrio, designated as Vibrio sp. GNUM08123. Agarase production by strain GNUM08123 was induced by agar and sucrose, but was repressed probably owing to carbon catabolite repression by glucose and maltose.

• Mycobiology
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• v.32 no.2
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• pp.88-94
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• 2004

Protoplasts of the wild type strain of Pleurotus osteatus were mutagenized with UV light, and 3,000 colonies were examined for abnormal mycelial and fruiting phenotypes. Forty one strains displayed variant phenotypes in mycelia and fruiting processes. The variant phenotypes were classified into 6 groups: (1) auxotrophic strains, which are incapable of growing on minimal media and can only grow when provided with their specific requirements; (2) abnormal vegetative strains, which grow very slowly on minimal and complete media; (3) primordiumless strains, which fail to develop to the formation of primordia; (4) maturationless strains, which form primordia, but do not form mature fruiting bodies; (5) specifically colored strains, which have Specific bluish grey or bluish white pileus; (6) poorly spored strains, which fail to produce basidiospore or which produce few spores. These variant strains may be useful in genetic breeding programs and for the studies of fungal development and genetics.