• Microbiology and Biotechnology Letters
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• v.46 no.1
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• pp.40-44
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• 2018

An isolate capable of inhibiting the growth of gram-positive bacteria was obtained from the soil of Mushim stream, Cheongju. The isolate was identified as Pseudomonas otitidis PS by 16S rRNA gene sequence analysis. P. otitidis PS produced antibiotics as a secondary metabolite when cultured in 1% soybean meal with 0.5% glucose. The maximum yield was about 0.1%. The antibiotic substance of P. otitidis PS extracted using ethyl acetate displayed a minimum inhibitory concentration of $2{\mu}g/ml$ for Staphylococcus aureus KCTC 1261. The antibiotic substance produced an orange halo on chrome azurol S agar due to siderophore activity. Growth inhibition was decreased when the iron was depleted. Since the antibiotic activity was lost upon the addition of the reducing agent ascorbic acid or during anaerobic culture, it was considered that antibiotic of P. otitidis PS strain exerts its bactericidal effect by the generation of reactive oxygen species.

• Korean Journal of Microbiology
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• v.48 no.3
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• pp.220-224
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• 2012

In order to reduce harmful biogenic amines in the traditionally fermented soybean products, five isolates with biogenic amines-degrading property were obtained from 83 traditionally fermented soybean products. The strains were found to reduce biogenic amines including histamine, tyramine, putrescine, and cadaverine by 27 to 92% in the cooked soybean containing 5.3% of each biogenic amine over 10 days of incubation. The morphological and biochemical tests and the phylogenetic relationships based on 16S rRNA gene sequences indicated that the five isolates were most closely related to Bacillus subtilis or B. amyloliquefaciens. The use of selected strains would be a potential control measure in manufacturing traditionally fermented soybean products that are difficult to control biogenic amine levels.

• Journal of fish pathology
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• v.31 no.2
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• pp.87-92
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• 2018

A case of disease was occurred in tiger puffer, Takifugu rubripes, reared in circulated system (water temperature was about $20^{\circ}C$) on land in Korea. Diseased fish showed a unique external sign, the cloudy skin ulcer in various sizes. We investigated the cause of disease, and isolated one pure cultured bacterium, TP01. This had 99.7% homology with Vibrio atlanticus by sequence analysis of the 16S rRNA and rpoA genes. TP01 showed some differences with other reported V. atlanticus strains in the biochemical characteristics as like Voges-Proskauer test and gelatin hydrolysis.

• Journal of Veterinary Clinics
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• v.32 no.2
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• pp.158-161
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• 2015

Bacterial dermatitis is common disease that is necessary to treat with antibiotics. In recent, antibiotic-resistant bacteria is being increased in worldwide. The purpose of the present study was to evaluate the prevalence of resistant genes in Staphylococcus (S.) pseudintermedius isolated from dogs, and to compare the resistant gene profile with the result of antibiotic disc diffusion test. A total of seven S. pseudintermedius was included in the study. Bacterial identification was performed by 16S ribosomal RNA gene sequence analysis. S. pseudintermedius isolates had more than one antibiotic resistant gene (mecA, blaZ and aac(6')/aph(2"). While all isolates were PCR positive to blaZ gene, only two isolates were resistant to amoxicillin/clavulanate. Among five isolates harboring gentamicin resistance, one isolate was negative to aac(6')/aph(2")-targeted PCR. Taken together, the results suggest that resistant gene-targeted PCR and disc diffusion test are complementary to detect antibiotic resistance.

• Journal of Life Science
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• v.23 no.12
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• pp.1486-1494
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• 2013

A high protease-producing strain was isolated and identified from the digestive tract of octopus vulgaris by detecting a hydrolysis circle of protease and its activity. The strain was identified by morphology observation, biochemical experiments, and 16S rRNA sequence analysis. The protease obtained from the strain was purified by a three-step process involving ammonium sulfate precipitation, carboxy methyl-cellulose (CM-52) cation-exchange chromatography, and DEAE-Sephadex A50 anion-exchange chromatography. The properties of protease were characterized as well. The strain Bacillus sp. QDV-3, which produced the highest activity of protease, was isolated. On the basis of the phenotypic and biochemical characterization and 16S rRNA gene-sequencing studies, the isolate was identified as follows: domain: Bacteria; phylum: Firmicutes; class: Bacilli; order: Bacillales; family: Bacillaceae; and genus: Bacillus. The isolate was shown to have a 99.2% similarity with Bacillus flexus. A high active protease designated as QDV-E, with a molecular weight of 61.6 kDa, was obtained. The enzyme was found to be active in the pH range of 9.0-9.5 and its optimum temperature was $40^{\circ}C$. The protease activity retained more than 96% at the temperature of $50^{\circ}C$ for 60 min. Phenylmethylsulfonyl fluoride (PMSF) inhibited the enzyme activity, thus confirming that this protease isolated from Bacillus sp. QDV-3 is an alkaline serine protease. Metal ions, $Mn^{2+}$ and $Mg^{2+}$, were determined to enhance the protease activity, whereas $Ba^{2+}$, $Zn^{2+}$, and $Cu^{2+}$ were found to inactivate the enzyme.

• The Korean Journal of Pesticide Science
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• v.20 no.3
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• pp.189-196
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• 2016

Several microorganisms in particular Bacillus subtilis group have been isolated from diverse places such as soils and the gastrointestinal tract of ruminants etc., and used as biocontrol agent against various plant pathogens and utilized as plant growth promoting agents. Among them, Bacillus is well known as one of the most useful bacteria for biocontrol and plant growth promotion. Bacterium GH1-13 was isolated from a reclaimed paddy field in Wando Island and identified as Bacillus velezensis using phylogenetic analysis on the basis of 16S rRNA and gyrB gene. It was confirmed that GH1-13 produced indole acetic acid (IAA) associated with promoted growth of rice root. GH1-13 showed characteristics of antagonization against the main pathogen of rice as well as diverse pathogenic fungi. GH1-13 had biosynthetic genes, bacillomycin, bacilycin, fengycin, iturin, and surfactin which are considered to be associated closely with inhibition of growth of pathogenic fungi and bacteria. This study showed that GH1-13 could be used as a multifunctional agent for biocontrol and growth promotion of crop.

• Toxicological Research
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• v.21 no.3
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• pp.209-218
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• 2005

We investigated effects of recombinant human erythropoietin (rHuEPO) on profiles of mRNA transcripts in 6 male cynomolgus (M. fascicularis) monkey's spleen for 4 weeks. Six monkeys, composed of control and treatment group (Control : M1, M2, M3: Treatment : M4, M5, M6) were intravenously administered 3 times per week without or with a dose of rHuEPO 2730 IU/0.1 ml/kg. After 4 weeks rHuEPO treatment, spleen was removed for RNA isolation. Splenic gene expression was assessed using Affymetrix U133A 2.0 arrays containing 18,400 transcripts and variants, including 14,500 well-characterized human genes. Gene expression pattern was very different between individuals even in same treatment. In rHuEPO treated groups showed number of genes were up- or down-regulated (M4: 79: M5: 48; M6: 73 genes). Six genes (epidermal growth factor receptor, calgranulin A, estrogen receptor binding site associated antigen, matrix metalloproteinase 19, zinc finger and BTB domain containing 16, progestin and adipoQ receptor) were commonly expressed in rHuEPO treated group. The different individual response could be major considering factor in monkey experiment. Further study is needed to clarify the different individual response to rHuEPO in molecular level. This study will be valuable in the fundamental understanding and validation of molecular toxicology for bio-generic drugs including rHuEPO in cynomolgus monkey.

• Korean Journal of Microbiology
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• v.45 no.1
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• pp.26-31
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• 2009

This study was aimed at the analysis of prokaryote communities in Korean traditional fermented food, jeotgal, and isolation of a novel strain from jeotgal by using culture-dependent and molecular biological approaches. Seventeen kinds of jeotgal were selected on the basis of its origins and sources. The samples were inoculated on 12 kinds of media. 308 isolates were selected randomly by morphological features, and its 16S rRNA gene sequences was amplified by PCR technique with bacteria and archaea specific primers (8F, 21F, and 1492R). The 16S rRNA gene sequences were compared with those in EzTaxon and GenBank databases. DNA-DNA hybridization was performed to identify a novel strain. As a result, the majority of the isolates were lactic acid bacteria (Leuconostoc, Weisella, Lactococcus, Lactobacillus, Carnobacterium, Marinilactibacillus), Bacillus, Pseudomonas, Micrococcus, Brevibacterium, Microbacterium and Kocuria in 17 kinds of jeotgal. The strains belonging to Salinicoccus, Halomonas, Cobetia, Lentibacillus, Paracoccus, and Psychrobacter were isolated as minor ones. Fourteen novel species were identified based on phylogenetic analysis.

• Microbiology and Biotechnology Letters
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• v.41 no.4
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• pp.462-468
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• 2013

Jeotgal is a generic term given to the high-salt-fermented seafood of Korea. This study aimed at developing an overview of the bacterial community present in Ojingeo-jeotgal, a highly consumed type of jeotgal, which is made with squid. Bacteria were isolated and purified from two samples on six different kinds of media and identified by 16S rRNA gene sequence analysis. Among the 121 total isolates, the most dominant genus was Bacillus, followed by coagulase-negative staphylococci (CNS) and lactic acid bacteria (LAB). CNS were detected in both samples, but LAB were observed in only a single sample. Six strains of Bacillus species inhibiting the growth of food pathogens, Staphylococcus aureus and Vibrio parahaemolyticus, were selected from the 121 isolates. These were found to inhibit the growth of both pathogens in addition to displaying proteolytic activities on media containing 6% NaCl and 2% skim milk.

• Korean Journal of Microbiology
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• v.50 no.3
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• pp.233-238
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• 2014

For the collection of starters suitable for the brewing of traditional liquor, an alcohol-resistant strain of lactic acid bacteria with low level of acid production was isolated from traditional fermented soybean lumps. The strain named as JBE 30 was identified as Lactobacillus brevis by 16S rRNA sequence analysis and additional biochemical tests. The strain could grow well at a MRS medium containing 8% (v/v) ethanol for 96 h of cultivation at $30^{\circ}C$. The final pH after cultivation was 4.5. It also inhibited the growth of food spoilage and pathogenic bacteria including Escherichia coli, Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus, Micrococcus luteus, and Pseudomonas aeruginosa. These results showed that Lactobacillus brevis JBE 30 could be used as a promising starter in brewing process of traditional liquor.