• Journal of Microbiology and Biotechnology
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• 제8권3호
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• pp.191-196
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• 1998

This mini review describes the effects of water activity (${\alpha}_w$) on the kinetics, regio- and enantioselectivities of lipases, and various methods for measuring and controlling ${\alpha}_w$ in lipase catalyzed reaction in organic solvent.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2000년도 International Meeting 2000
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• pp.94-101
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• 2000

We investigated the viral contamination of water environment including tap water in Korea. River water used for source water was analyzed about monthly between 1997 and 1999 over a period 26 months. A total of 22 tap water samples were collected in 10 sites in 2 urban areas between 1997 and 1998 over a 11 months. All samples were examined for infectious enteroviruses and adenoviruses by a cell culture technique followed by PCR amplification. To identify the recovered viruses from tap water, sequence analysis of PCR products was performed. Infectious viral particles were detected in river water all year round, ranging from 0.93 to 17.3 Most Probable Number of Infectious Unit (MPNIU) /100L. Tap water samples also contained infectious viral particles. The frequency of enteroviruses and adenoviruses in tap water were $50.0\%$ (11/22) and $36.7\%$ (8/22), respectively. Both enteroviruses and adenoviruses were detected in five tap water samples $(22.7\%)$. The level of viral contamination in tap water was quite high, ranging from 0.2 to 2.9 MPNIU/100L, far above the recommended virus level in drinking water set by the U.S. EPA. Poliovirus type 1 derived from vaccine was frequently detected and the remainder comprised coxsackievirus B type or echovirus type 6, which were causative agents of aseptic meningitis in Korea in 1997 and 1998, respectively. Several types of adenovirus were detected in tap water samples and some water samples were found to contain adenoviruses which were closely related to enteric adenovirus type 40 and 41. This stusy shows that surface water and tap water in Korea may be exposed to the risk of viral contamination, especially from recently recognized viruses and this constitutes a potential public health hazard.

• Journal of Microbiology and Biotechnology
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• 제23권8호
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• pp.1092-1098
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• 2013

Cassava constitutes an abundant substrate in tropical regions. The production of butanol in ABE fermentation by Clostridium beijerinckii BA101 using cassava flour (CF) was scaled-up to bioreactor level (5 L). Optimized fermentation conditions were applied; that is, $40^{\circ}C$, 60 g/l CF, and enzymatic pretreatment of the substrate. The batch fermentation profile presented an acidogenic phase for the first 24 h and a solventogenic phase afterwards. An average of 37.01 g/l ABE was produced after 83 h, with a productivity of 0.446 g/l/h. Butanol production was 25.71 g/l with a productivity of 0.310 g/l/h, high or similar to analogous batch processes described for other substrates. Solvent separation by different combinations of fractioned and azeotropic distillation and liquid-liquid separation were assessed to evaluate energetic and economic costs in downstream processing. Results suggest that the use of cassava as a substrate in ABE fermentation could be a cost-effective way of producing butanol in tropical regions.

• 미생물학회지
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• 제53권2호
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• pp.144-145
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• 2017

Bacillus subtilis를 이용하여 청국장 발효 연구를 진행하던 중 발효능이 뛰어난 B. subtilis G24라는 균주를 새로 분리하였고, 이를 숙주로 이용하는 bacteriophage SPG24를 새로 분리하였다. 본 연구에서는 bacteriophage SPG24의 유전체 서열을 해독하였으며 전체길이 152,060 bp, G+C 함량 42.2%, 232개 ORF의 bacteriophage SPG24는 B. subtilis G24를 숙주로 이용함으로써 청국장 발효를 저해하는 것으로 확인되었다.

• 한국환경보건학회지
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• 제14권1호
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• pp.55-61
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• 1988

Study was conducted on how the phosphorus content of algae changed by the algal species and the algal growth conditions. Phosphorus contents were not so different by algal species if algae grow on the same phosphorus concentration. Phosphorus content of algae grown on higher P medium was higher than that of algae grown on lower P medium. Algae excrete P-compounds from cell to the medium when the dissolved reactive phosphorus is depleted in the medium, and the excreted P-compounds were decomposed by algae and used for the growth of algae. Phosphorus content of algae grown in the P-limited condition was about 5-1 $\mu$gP/mg dry wt., but that of algae grown in the condition not P-lirnited was above 10$\mu$gP/rng dry wt.

• Journal of Microbiology and Biotechnology
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• 제8권1호
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• pp.67-73
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• 1998

A bacterial strain that excretes hemolysins and proteases into the growth medium was isolated from sea water and designated as KYJ 961. A nearly complete nucleotide sequence of a 16S ribosomal RNA gene from the isolate was determined following the isolation and cloning of amplified genes. On the basis of the 16S ribosomal DNA sequence data, and morphological, chemotaxonomic, and physiological characteristics, strain KYJ 961 was classified as a strain of Bacillus cereus.

• Journal of Microbiology and Biotechnology
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• 제10권1호
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• pp.43-47
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• 2000

In vitro cytotoxicity and antioxidative effects of water extracts prepared from Mustard Leaf Kimchi (MLK) during its fermentation period were investigated. The cytotoxicity against HepG2 (human hepatic cancer) by water extracts from the well fermented Mustard Leaf Kimchi was higher than others (fermented for 0 to 6 days at 18$^{\circ}C$), and IC50 of water extracts at the points of 6, 8, 10, and 14days during fermentation were 213.4, 99.2, 99.9, and 109.8${\mu}{\textrm}{m}$/ml, respectively. Antioxidative activity of water extracts from MLK during various fermentation periods was higher than that of blank distilled water. However, the antioxidative activity of well-fermented water extracts of MLK (fermented for 8-14 days) did not show any difference from that of others (fermented for 2-6 days). Thus, water extracts of well-fermented MLK (fermented during 8-14 days) significantly inhibited the growth of cancer cells in vitro, but little antioxidative activity was influenced by the various fermentation periods.

• Journal of Microbiology and Biotechnology
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• 제17권5호
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• pp.853-857
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• 2007

The semi-outdoor cultivation of Spirulina platens is was attempted using an underground-water-based medium. Occurrence of contaminant organisms such as Chlorella sp. and Chlamydomonas sp. was not found from a microscopic observation and bacteria were not detected from denaturing gradient gel electrophoresis(DGGE) analysis of PCR-amplified 16S rDNA during the cultivation, owing to pH control and the high quality of the underground water. The mean productivity was high at $10.5g/m^2/d$ with a range of $4.2-12.3g/m^2/d$ despite the unfavorable weather conditions of the rainy season. The cultivated S. platens is included a normal protein content of 58.9%. Consequently, the underground water improved the biomass productivity and the biomass quality because of an abundant supplementation of natural minerals and through a contaminant-free culture.

• 치위생과학회지
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• 제15권4호
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• pp.383-392
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• 2015

치과치료를 위해 다양한 용도로 DCU에서 배출되는 물이 사용된다. 이 DCU 물의 질에 관한 계속되는 논란으로 인한 환자들의 불안감을 줄이고 양질의 치과 치료를 제공하기 위해서는 DCU 물이 음용수만큼 깨끗하게 유지되어야 한다. 따라서 본 논문은 DCU 물의 세균 오염 수준과 오염된 DCU 물의 임상적 위험성에 대하여 설명하고, 세균 오염을 방지하기 위한 여러 가지 관리 방법들을 검토하였다. 여러 국가에서 DCU 물을 대상으로 오염도를 확인하는 연구가 많이 진행되어 DCU 물이 높은 수준으로 오염되어있다는 것이 입증되었다. 오염된 DCU 물로 인해 감염된 일부 사례도 보고되었고 이는 DCU 물이 감염의 잠재적인 원인일 수 있음을 보여주었다. DCU 물로 인한 잠재적 감염의 위험성을 줄이기 위해서는 효율적인 소독방법을 사용하고 자체적인 모니터링 또한 시행되어야 한다. 하지만 제안되고 있는 여러 가지 수관관리 소독방법으로 인해 치과종사자들의 혼란이 야기되고 있으며, 효율적인 소독방법을 보편화하기 위해서는 관련 연구가 더 진행되어야 할 것으로 생각된다. 치과치료를 받는 환자들을 안심시킬 수 있는 좋은 치과서비스를 제공하기 위해서는 정책적인 개선과 국내 치과 상황에 맞는 수관 관리 지침이 빠른 시일 내에 시행되어야 할 것으로 생각된다.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1998년도 한국생물과학협회 학술발표대회
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• pp.180.1-180
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• 1998

No Abstract, See Full Text