• Korean Journal of Microbiology
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• v.54 no.2
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• pp.158-160
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• 2018

Streptomyces sp. P3 was isolated from potato scab diseased tubers in Pyeongchang, Gangwon-do, Republic of Korea in 2017. Here, we report the draft genome sequences of P3 with 9,851,971 bp size (71.2% GC content) of the chromosome. The genome comprises 8,548 CDS, 18 rRNA and 66 tRNA genes. Although strain P3 did not show pathogenicity both potato tuber assay and radish seedling assay, it possesses tomatinase (tomA) gene among conserved pathogenicity-related genes in well characterized pathogenic Streptomyces. Thus, the genome sequences determined in this study will be useful to understand for pathogenic evolution in Streptomyces species, which already adapted to potato scab pathogens.

• Journal of Microbiology
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• v.41 no.4
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• pp.271-276
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• 2003

The inoculation of some microorganisms into a microcosm containing soil from a barren lakeside area at Lake Paro in Kangwon-do enhanced plant growth significantly. The direct and viable counts of soil bacteria and soil microbial activities measured by electron transport system assay and fluorescein diacetate hydrolysis assay were higher in inoculated soil. The plant growth promoting effect of this inoculation may be caused by phytohormone production and the solubilization of insoluble phosphates by the inoculated bacteria. Three inoculated strains of Pseudomonas fluorescens produced several plant growth promoting phytohormones, including indole-3-acetic acid (auxin), which was confirmed by thin layer chromatography and GC/MS. P. fluorescens strain B16 and M45 produced 502.4 and 206.1 mg/l of soluble phosphate from Ca3(PO4)2 and hydroxyapatite, respectively. Bacillus megaterium showed similar solubilization rates of insoluble phosphates to those of Pseudomonas spp. We believe that this plant growth promoting capability may be used for the rapid revegetation of barren or disturbed land.

• Korean Journal of Microbiology
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• v.41 no.4
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• pp.269-274
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• 2005

We evaluated the PCR assay and two commercialized PCR kits for the detection of mycoplasma in veterinary via live vaccines. The PCR assay could specifically detect all the tested Mycoplasma spp. and Acholeplasma spp., whereas two commercialized PCR kits did not. Also, the specificity of the PCR assay showed that 4 reference strains and 7 field isolates belonging to avian mycoplasma species could be all detected. The sensitivity of the PCR assay was determined using pure cultured Mycoplasma spp. and Acholeplasma spp. with a range of 1 to 100 colony forming units/ml in 9 CFR Mycoplasma broth. To test the availability of the PCR assay for veterinary live viral vaccines, A. laidlawii was artificially inoculated into the swine transmissible gastroenteritis-rota virus combined vaccine and canine parvovirus vaccine, respectively and the sensitivity of the PCR assay was similar with the result of cultured samples. In this study, the PCR assays could be used as rapid and sensitive methods for the detection of mycoplasma in veterinary live viral vaccines.

• Journal of Microbiology
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• v.38 no.1
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• pp.24-30
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• 2000

US3 gene is a member of the human cytomegalovirus (HCMV) immediate early gene. Although the precise functions of the US3 gene in HCMV replication and pathogenesis are not known, it has been reported to play a role in inhibiting major histocompatibility class I antigen presentation. For further knowledge of US3 gene expression, rabbit polyclonal antiserum of the US3 gene product was used for indirect immunofluorescence assay. In permissive human foreskin fibroblast (HFF) cells, US3 gene expression was detectable as crescent or half-moon shape in the perinuclear region at immediate early times after virus infection. HFF cells infected with mutant HCMV lacking US3 open reading frames were negative for US3 immunofluorescence assay. Double immunofluorescence assay using monoclonal antibody to gamma adaptin (specific for the Golgi complex) and rabbit anti-US3 antiserum revealed that US3 gene product could be localized to the Golgi complex. At later time after HCMV infection, US3 gene products were detected as globular aggregates in the cytosol. These aggregates were positive for gamma adaptin and stained with preimmune serum, suggesting a nonspecific reaction to the Golgi complex. Northern blot analysis revealed that transcription of US3 was observed only during immediate early times after virus infection (until 6 h postinfection). Therefore US3 gene expression appears to be confined to immediate early time and its gene products are localized to the Golgi complex as crescent shaped forms in the perinuclear cytoplasm.

• Korean Journal of Microbiology
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• v.52 no.1
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• pp.116-119
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• 2016

Stable maintenance of telomere is required for cell proliferation and survival. Although telomerase is the primary means for telomere maintenance, recombination is another important pathway to maintain telomeres. In this study, we developed a genetic assay for telomere recombination using the internal $TG_{1-3}$ repeats present in subtelomeric regions of yeast. The recombination frequencies were dependent on the presence of the internal $TG_{1-3}$ repeats. PCR amplification of the regions near URA3 and CAN1 markers using genomic DNA isolated from $FOA^rCan^r$ colonies indicated that each isolate had lost the chromosome end including the markers. In addition, the recombination frequencies increased with longer internal $TG_{1-3}$ repeats. Our results suggest that the $FOA^rCan^r$ colony formation is the consequence of recombination between the internal and terminal $TG_{1-3}$ repeats.

• Journal of Microbiology
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• v.42 no.2
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• pp.99-102
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• 2004

Bacteriophage PM2 has a closed circular form of double stranded DNA as a genome. This DNA from the phage is a useful source for nick-circle endonuclease assay in the fmol range. Due to difficulties in the maintenance of viral infectivity, storage conditions of the phage should be considered for the puri-fication of PM2 DNA. The proper condition for a short-term storage of less than 2 months is to keep the PM2 phage at 4$^{\circ}C$; whereas the proper condition for a long-term storage of the PM2 phage for over 2 months is to keep it under liquid nitrogen in 7.5 ％ glycerol. The optimal conditions for a high yield of phage progeny were also considered with the goal to achieve a successful PM2 DNA preparation. A MOI(Multiplicity Of Infection) of 0.03, in which the OD$\sub$600/ of the host bacteria was between 0.3 and 0.5, turned out to be optimal for the mass production of PM2 phage with a burst size of about 214. Considerations of PM2 genome size, and the concentrations and radiospecific activities of purified PM2 DNA, are required to measure the endonuclease activity in the fmol range. This study reports the proper quantitation of radioactivity and the yield of purified DNA based on these conditions.

• Korean Journal of Microbiology
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• v.34 no.4
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• pp.231-235
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• 1998

We have introduced a genetic assay to study the existence of intramolecular triplexes in Escherichia coli. A plasmid containing the gene that encodes a temperature-sensitive EcoRI methylase was cotransformed with different plasmids containing inserts, $(G)_9AATTC(G)_9$ and $(GAA)_9TTC(GAA)_8$, that are able to form intramolecular triplexes in vitro. Inhibition of methylation in vivo was found for $(G)_9AATTC(G)_9$ and $(GAA)_9TTC(GAA)_8$, suggesting that the pur pyr sequences adopt unusual strucures in E. coli. In addition, experiments using two dimensional gel electrophoresis confirmed that intramolecular triplexes are formed for the pur pyr sequences under negative supercoiling. These results demonstrate the existence of intramolecular triplexes in E. coli.

• Journal of Microbiology
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• v.42 no.4
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• pp.336-339
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• 2004

The antibacterial actions of two amino acid oxidases, a D-amino acid oxidase from hog kidney and a L-amino acid oxidase from the venom of Agkistrodon halys, were investigated, demonstrating that both enzymes were able to inhibit the growth of both Gram-positive and Gram-negative bacteria, and that hydrogen peroxide, a product of their enzymatic reactions, was the antibacterial factor. However, hydrogen peroxide generated in the enzymatic reactions was not sufficient to explain the degree to which bacterial growth was inhibited. A fluorescence labeling assay showed that both of these two enzymes could bind to the surfaces of bacteria. To the best of our knowledge, this is the first report regarding the antibacterial activity of the D-amino acid oxidases.

• Journal of Microbiology
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• v.45 no.6
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• pp.583-589
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• 2007

The promoter region of pyrC (dihydroorotase) gene of Escherichia coli was shown to have Fur protein binding properties by gel retardation assay. In vivo regulation of the pyrC expression was studied by measuring dihydroorotase activity and ${\beta}$-galactosidase level in the $fur^+$ and $fur^-$ genetic background. The expression of chromosomal dihydroorotase activity and ${\beta}$-galactosidase activity of pyrC-lacZ fusion plasmid was repressed to about 30% and 17%, respectively in the $fur^+$ strain compared to those in the $fur^-$ strain. Divalent ions such as $Fe^{2+}$ and $Zn^{2+}$ were not required for the repression. PyrC expression was also reduced to one half by 1 mM uracil. The effect of uracil was independent on the fur gene.

• Journal of Microbiology
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• v.42 no.3
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• pp.239-242
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• 2004

This study examined the detection rate of the hepatitis B virus (HBV) and Mycobacterium tuberculosis (Mtb) in serum and saliva samples, respectively, from 120 dental patients who were unaware if they have or had either hepatitis or tuberculosis. The frequencies of HBsAg and anti-HBs were determined using an immunochromatic assay. Mtb positivity was determined by the PCR method. Of the 120 patients, 7 (5.8％) were HBV positive and 30 (25.0％) were Mtb positive. This highlights the fact that dental health care workers (DHCWs) can be exposed to the risk of infection from blood- or saliva-borne pathogens as a consequence of their work. Therefore, it is very important to prevent cross infection between patients and dental personnel. Accordingly, laboratory tests prior to surgical treatment are needed to determine the infectious state of dental patients in order to prevent the transmission of infectious diseases in dental clinics.