• Journal of Environmental Health Sciences
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• v.34 no.6
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• pp.403-413
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• 2008

Toxic effect of methyl tert-butyl ether (MTBE), tert-butyl alcohol (TBA) and formaldehyde (FA) on microbial activity and diversity was compared in rice field, leek patch, and tidal mud flat soil samples. MTBE, TBA and FA with different concentrations were added into microcosms containing these soil samples, and placed at room temperature for 30 days. Then the microbial activities such as dehydrogenase and viable cell numbers and microbial community using a DGGE (Denaturing gradient gel electrophoresis) fingerprinting method were measured. Among the samples, dehydrogenase activity in rice field was inhibited the most by MTBE, TBA and FA. The toxic effect was higher according to the following orders: FA > MTBE > TBA. Dominant species in the microcosms contaminated with MTBE, TBA and FA were Chloroflex, Bacilli, gamma-proteobacteria in the rice field sample, Sphingobacteria, Flavobacteria, Actinobacteria, Bacilli, gamma-proteobacteria in the leek patch sample, and Sphingobacteria, Flavobacteria, delta-proteobacteria, gamma-proteobacteria in the tidal mud flat sample.

• Korean Journal of Veterinary Research
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• v.50 no.1
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• pp.59-62
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• 2010

A 2-year-old lineolated parakeet (Bolborhynchus lineola) was presented with abdominal distention and respiratory distress for two months. The bird was poorly fleshed and the liver was enlarged on coelomic palpation. Plain and contrast radiographic examinations exhibited hepatomegaly and distended intestinal loop, which compromised the air sacs. Multifocal hyperechogenecity was observed in the liver on ultrasonography. Postmortem gross examination revealed hepatomegaly with numerous pinpoint tan foci in the hepatic parenchyma and distended small intestine filled with adult ascarids. Microscopically, granulomatous hepatitis and enteritis infected by intrahistiocytic acid-fast bacilli were evident. Polymerase chain reaction indicated that the acid-fast bacilli were Mycobacterium avium subsp. avium.

• The Journal of the Korean Society for Microbiology
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• v.21 no.1
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• pp.53-62
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• 1986

An attempt was made to verify the antibacterial activities of the soluble extracts of Gardenia jasminoides(SEGJ) against mycobacteria other than tubercle bacilli (MOTT); M. kansasii, M. scrofulaceum, M. simiae, M. szulgai, M.xenopi, M. avium-intracellulare complex, M. gordonae and M. flarescens. In addition, the effect of the SEGJ on the yellow pigmentation and violet pigmentation (crocin reaction) of the colonies of the MOTT grown on7H10-crocin agar plates was observed. The SEGJ gave a growth stimulatory activity against most species of mycobacteria except for M. szulgai at low concentration of the SEGJ in terms of crocin pigment OD=0.02 or less, but exerted an inhibitory activity at high concentration of OD=0.04 or more. The growth-inhibitory activity of the SEGJ was dose-dependent but the yellow pigmentation of the scotochromogens was not affected by the dose of the SEGJ that was growth-inhibitory. Crocin positive reaction was observed only with M. kansasii.

• Journal of Microbiology and Biotechnology
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• v.21 no.11
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• pp.1166-1173
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• 2011

Meju is a traditional Korean fermented soy product used as a key element for soy sauce and doenjang. Bacilli with antimicrobial activity were isolated from meju prepared by traditional methods at Sunchang county, Jeollabukdo, Korea. Six isolates were identified as Bacillus amyloliquefaciens by recA gene sequencing and RAPD-PCR. One isolate, B. amyloliquefaciens MJ5-41, showed the strongest fibrinolytic activity. A 27 kDa active fibrinolytic enzyme, AprE5-41, was purified from the culture supernatant of MJ5-41 grown on LB by chromatographic methods. The optimum pH and temperature for purified AprE5-41 were 7.0 and $45^{\circ}C$, respectively. AprE5-41 quickly degraded $A{\alpha}$ and $B{\beta}$ chains but not the ${\gamma}$-chain of fibrinogen. AprE5-41 exhibited the highest specificity for N-succinyl-Ala-Ala-Pro-Phe p-nitroanilide, a known substrate for ${\alpha}$-chymotrypsin, cathepsin G, and subtilisin BPN'. The structural gene, aprE5-41, was cloned by PCR and successfully expressed in B. subtilis.

• Journal of Species Research
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• v.9 no.2
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• pp.105-116
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• 2020

A total of 37 anaerobic bacteria strains within the classes Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Bacteroidia, Flavobacteriia, Bacilli, Clostridia, and Fusobacteriia were isolated from freshwater and sediment of the Geum River in Korea. The unreported species were related with Rhizobium and Oleomonas of the class Alphaproteobacteria; Acidovorax, Pseudogulbenkiania, and Aromatoleum of the class Betaproteobacteria; Tolumonas, Aeromonas, Cronobacter, Lonsdalea, and Phytobacter of the class Gammaproteobacteria; Bacteroides, Dysgonomonas, Macellibacteroides, and Parabacteroides of the class Bacteroidia; Flavobacterium of the class Flavobacteriia; Bacillus and Paenibacillus of the class Bacilli; Clostridium, Clostridioides, Paraclostridium, Romboutsia, Sporacetigenium, and Terrisporobacter of the class Clostridia; and Cetobacterium and Ilyobacter of the class Fusobacteriia. A total of 37 strains, with >98.7% 16S rRNA gene sequence similarity with validly published bacterial species, but not reported in Korea, were determined to be unrecorded anaerobic bacterial species in Korea.

• Korean journal of food and cookery science
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• v.13 no.3
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• pp.293-298
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• 1997

The changes of microorganisms, pH, color and flavor were examined in the chicken treated with O％, 1%, 2%, and 3% lactic acid solutions during the storage at 4$^{\circ}C$. Lactic acid treatment inhibited the growth of mesophiles, psychrotrophs, and enteric bacilli as the concentration increased, however, it was not effective on yeasts and molds. Extension of lag phase for mesophilic bacteria and suppression of log phase for psychrotrophs and enteric bacilli were observed in the growth inhibition patterns. The pH of the chicken increased during the storage and antimicrobial effect of lactic acid appears to be due to mainly the decrease of pH. No flavor change of the chicken was observed by any lactic acid treatment, however, 3％ lactic acid caused discoloration of the chicken.

• Tuberculosis and Respiratory Diseases
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• v.84 no.1
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• pp.1-12
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• 2021

Mycobacterium tuberculosis has infected more than two billion individuals worldwide, of whom 5%-10% have clinically active disease and 90%-95% remain in the latent stage with a reservoir of viable bacteria in the macrophages for extended periods of time. The tubercle bacilli at this stage are usually called dormant, non-viable, and/or non-culturable microorganisms. The patients with latent bacilli will not have clinical pictures and are not infectious. The infections in about 2%-23% of the patients with latent status become reactivated for various reasons such as cancer, human immunodeficiency virus infection, diabetes, and/or aging. Many studies have examined the mechanisms involved in the latent state of Mycobacterium and showed that latency modified the expression of many genes. Therefore, several mechanisms will change in this bacterium. Hence, this study aimed to briefly examine the genes involved in the latent state as well as the changes that are caused by Mycobacterium tuberculosis. The study also evaluated the relationship between the functions of these genes.

• Biomedical Science Letters
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• v.29 no.4
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• pp.256-262
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• 2023

The purpose of this study is to investigate microbial contamination in water purifiers from two universities (A and B) in Chungcheong region and to evaluate about the harmfulness of the isolated bacteria to the human. The degree of microbiological contamination of six water purifiers at university A was investigated three times from July 2018 to September 2019, and nine water purifiers at university B were investigated in 2023. The isolated bacteria were biochemically identified using an API kit and Vitek-2 system, and then the bacteria were identified to the species level using MALDI-TOF MS. In addition, the possibility of human infection of the isolated bacteria was evaluated through a literature search. In July 2018 and September 2019, the number of bacteria isolated inside the faucet was below the acceptable standard for hot water, but exceed for cold water in all water purifiers. In January and September 2019, bacteria exceeding the acceptable standards were isolated nine times from the cold water of six water purifies (a total of 12 water purifiers). Bacteria identified by MALDI-TOF MS included anaerobic bacteria (Clostridium novyi, Clostridium themopalmarium etc.), Gram-positive bacilli (Microbacterium testaceum, Arthrobacter woluwensis etc.), and Gramnegative bacilli (Acinetobacter nosocomialis, Comamonas kerstersii etc.), which are difficult identify by biochemical methods. In conclusion, bacteria exceeding the acceptable standard were isolated from the cold water of most of the water purifiers. Most of the isolated bacteria were low-pathogenic bacteria from natural environment, but opportunistic bacteria that can cause infection in humans were also isolated from some water purifiers.

• Korean Journal of Agricultural Science
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• v.26 no.1
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• pp.77-83
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• 1999

The populations of microorganisms adhered on rice straws which had been ricked in the fields around Chungchong areas during the winter season from February to March in 1998 were investigated. The number of mesophilic bacteria including bacilli was generally high in the middle part of straw. And it appeared to be higher in the samples from rural areas than those from suburb. Thermophilic bacteria and actinomycetes were rarely to be detected in most samples. Coliform bacteria were detected in a few samples which collected from Kwanpyong-dong of Taejon-city, Jangpyong-meun and Jungsan-meun of Chongyang-koon, indicating that these areas were contaminated by sewage and livestock wastes. Following the fermentation of Chungkukgang employed the middle parts of straws from Mok-meun of Chongyang-koon as a source of microbial inoculum, qualities of the fermented products such as amino-nitrogen content, viscosity and protease activity, were examined: the application of rice straws resulted in better qualities of the fermented products when compared to the control, however the methods of application appeared to have little or no effect on the quality.

• Biomedical Science Letters
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• v.5 no.1
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• pp.17-26
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• 1999

To evaluate the spreading possibilities of the marRAB mutation of E. coli Mar mutant among gram-negative bacilli, chromosomal marRAB mutations of Mar mutants were transduced by $\lambda$placMu9 into pUC19 (Lac$^{+}$, Ap$^{r}$) cloning site in another strains of E. coli or onto the chrmosome of S. typhimurium and P. aeruginosa, selected for transduction by Mar phenotype, Lac$^{-}$, or Ap$^{r}$, and tested for their antimicrobial resistance with or without addition of salicylate (SAL). Compared with wild type strains of JM109, NM522, harboring pUC19 or not, respectively, all strains of JM109 or NM522 carrying pUC19::marRAB mutation showed higher levels of antimicrobial resistance and SAL induction of Mar phenotype than those of wild type. However, in contrast to the original Mar mutants, there were some tendencies of decreased antimicrobial resistance of JM109 or NM522 harboring pUC19::marRAB mutation with SAL induction against chlorarnphenicol (Cm) and tetracycline (Tc), or Tc and ciprofloxacin (Cp), respectively. Almost the same results, as shown as the cases of E. coli JM109 or NM522, were obtained from all transductants of S. typhimurium and P. aeruginosa, except Cp, against which increased antimicrobial resistance with SAL induction was shown. This study, employed the methods of transformation or transduction among intercellular gene transfer methods between gram-negative bacteria, shows the evidences that suggest indirectly the spreading possibilities of marRAB mutation among gram-negative bacilli.