• 한국환경보건학회지
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• 제34권6호
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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.

• 대한수의학회지
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• 제50권1호
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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.

• 대한미생물학회지
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• 제21권1호
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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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• 제21권11호
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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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• 제9권2호
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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.

• 한국식품조리과학회지
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• 제13권3호
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• pp.293-298
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• 1997

닭고기를 멸균한 증류수, 1%, 2%, 3% 젖산용액으로 처리하여 4$^{\circ}C$에서 보관하면서 미생물 수의 변화, pH의 변화, 색과 냄새의 변화를 조사하였다. 중온성균, 저온성균, 장내세균에 대해서는 젖산의 농도가 높아질수록 성장억제 효과가 증가하였고, 효모와 곰팡이에 대한 젖산의 성장억제 효과는 높지 않은 것으로 나타났다. 성장억제는 중온성균에서는 유도기가 연장되고, 저온성균에서는 대수기가 억제되는 형태로 나타났다. 저장기간 중 닭고기의 pH는 상승하였고, 젖산의 항미 생물효과는 주로 pH 저하에 의한 것으로 추정되었다. 3%까지의 젖산용액은 닭고기의 냄새에 유의적인 변화를 일으키지 않았으며, 1%와 2% 젖산용액은 닭고기의 색에 변화를 주지 않았으나, 3% 젖산용액은 탈색을 일으켰다.

• Tuberculosis and Respiratory Diseases
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• 제84권1호
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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.

• 대한의생명과학회지
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• 제29권4호
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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.

• 농업과학연구
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• 제26권1호
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• pp.77-83
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• 1999

월등한 볏짚을 1998년 2월 말부터 3월 초순 사이에 주로 대전을 중심으로 하는 충청지역에서 회수하고 이를 부위별로 구분하여 부착 세균류 및 진균류의 분포를 조사한 결과, 도시 근교지역보다 농촌지역의 볏집에서 일반 중온성 세균수가 많고 동시에 bacilli도 많았으나 진균류는 오히려 적은 경향을 보였다. 고온성 세균과 방선균의 분포는 낮았으며, 대장균도 일부 지역에서 검출되었다. 볏짚의 부위별 분포를 보면 대체적으로 가운데 부위에서 미생물수가 높게 나타났으며 bacilli의 분포를 고려한다면 청국장 제조에는 하루보다 중부 및 상부가 접종원으로서 바람하다고 할수있다. 청국장 제조를 위한 볏짚시료로서는 어느 지역의 것이라도 무방하겠으나 하수 및 축산폐수의 오염이 없는 것을 선택할 필요가 있겠다. 볏짚의 중간부위를 미생물 접종원으로 사용하여 청국장을 발효시킨 다음 그 품질을 평가한 결과, 볏짚을 사용한 경우 그대로 발효시킨 대조구에 비하여 외관, 점성도, 아미노태 질소함량, 단백질 분해력에 있어서 현저하게 양호한 결과를 보였다. 볏짚의 사용 방법간에, 즉 실험구 사이에는 발효후 성분상의 차이가 별로 없었으므로 사용방법에 따른 영향은 적었다.

• 대한의생명과학회지
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• 제5권1호
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• pp.17-26
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• 1999

Mar (multiple-antibiotic-resistance) 대장균의 marRAB 돌연변이가 그람음성 세균들 사이로 전파 될수 있는지를 알아보기 위해서, 염색체 위의 marRAB 돌연변이를 $\lambda$placMu9 (Km$^{r}$)를 이용하여 대장균의 다른 균주내의 pUC19 (Lac$^{+}$, Ap$^{r}$)의 클로닝 사이트, S. typhimurium 및 P. aeruginosa의 염색체 위로 각각 전달시킨 후, Mar phenotype, Km$^{r}$, Lac$^{-}$, 혹은 Ap$^{r}$ 균주를 선택한 다음, salicylate (SAL)의 유도 (induction) 유무에 따른 항생제 내성검사를 실시하였다. pUC19의 보유 유무에 관계없이 대조군인 야생형 대장균 JM109, NM522에 비해서, pUC19::marRAB 돌연변이를 가진 JM109 혹은 NM522의 대부분 균주들은 항생제 내성 수준들이 훨씬 더 높았으며, Mar표현형의 유도도 SAL에 의해서 훨씬 더 높게 나타났다. 하지만 일부 소수의 항생제에 대해서는 예외적으로 내성 수준이 더 낮게 나타났는데, 야생형 JM109 균주에서는 chloramphenicol (Cm)과 tetracycline (Tc)이 , pUC19::marRAB 돌연변이를 가진 NM522 균주 에서는 Tc와 ciprofloxacin (Cp)에 대한 내성 수준이 각각 더 낮게 나타났다. S. typhimurium 및 P. aeruginosa에 대한 같은 실험의 결과도 야생형 대장균의 경우와 거의 대부분 일치하였다. 형질전환 (transformation)과 형질도입 (transduction)의 방법을 주로 사용한 이 실험의 결과는, marRAB 돌연변이가 그람음성 세균들 사이로 전파될 수 있음을 간접적으로 암시한다.