• Journal of Microbiology and Biotechnology
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• 제2권2호
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• pp.115-121
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• 1992

In order to broaden the spectrum of substrate utilization of a Gram negative bacterium Zymomonas mobilis which has a great potential as an industrial ethanol producing microorganism, cloning of $\alpha$-amylase gene into Z. mobilis ZM4 was tried. The $\alpha$-amylase gene was isolated from Bacillus stearothermophilus. By Southern blot analysis, it was proven that the $\alpha$-amylase gene fragment was originated from a naturally occuring plasmid of B. stearothermophilus ATCC 31195. To place $\alpha$-amylase gene under the control of Z. mobilis promoter, two different Z. mobilis expression vectors, pZA26 and pLOI204, were used. The truncated $\alpha$-amylase gene was then introduced into these vectors. Both qualitative and quantitative activities of $\alpha$-amylase were observed in Z. mobilis cells harboring these plasmids with the $\alpha$-amylase gene inserted. Gas chromatographic analysis of ethanol showed that one of the Z. mobilis transconjugants was capable of producing 67 mM ethanol from rich medium(RM) containing 5% soluble starch as a sole carbon source.

• International Journal of Contents
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• 제11권1호
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• pp.52-61
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• 2015

In the past decade, East Asian Research has received attention from researchers as well as in South Korea society-at-large. The broad category of East Asian Research includes various disciplinary fields, such as "history, economics, and politics; however, few studies have used quantitative analysis to explore its development. In this paper, we used network analysis to identify the disciplines and active research areas, focusing on productivity, collaboration patterns, and citation networks of East Asian Research in South Korea. For this study, 6,646 journal publications related with East Asian Research and indexed by KCI (Korean Citation Index) during the 10-year period of 2004-2013 were considered. Results show that East Asian Research was led during this period by sole-researchers, rather than interdisciplinary studies. Moreover, a co-institution network represents active institutions with a high degree and collaborative centrality. In terms of journal-journal citation networks, journals belonging to both "history" and "Korean literature" disciplines were dominant.

• 한국미생물·생명공학회지
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• 제27권5호
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• pp.399-403
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• 1999

For the production of trehalose, microorganisms capable of producing trehalose extracellularly were screened from the stock cultures in our laboratory. among them, Micrococcus luteus IFO 12708 showed the highest productivity of trehalose. For the increase of productivity, the mutant strai Hs-208 having higher trehalose production was selected with NTG(N-methyl-N'-nitrosoguanidine) mutagenesis, which led to the decrease of the specific activity of trehalose phosphorylase(3.2-fold) as compared to the wild strain. The optimum condition for the trehalose production was established as follows: 20g/l of glucose and 6g/l of tryptone were used as a sole carbon source and nitrogen source, respectively, and cultivations were carried out at 3$0^{\circ}C$ and pH 6.0. After 20hrs cultivation, addition of 20unit/ml penicillin G led to the higher conversion yield of trehalose. Under the optimum condition, 6.547g/l trehalose was produced with conversion yield of 32.7%.

• 한국미생물·생명공학회지
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• 제17권2호
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• pp.85-87
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• 1989

토양으로부터 분리한 Xylose 발효효모 X-6-41 (Candida sp.)의 xylanase 효소생성 조건을 조사해 본 결과, 본 실험에 사용한 X-6-41 균주는 배지조성중 yeast extract 혹은 polypeptone이 첨가되면 xylanase 효소생성이 없었다. 즉 특정 아미노산인 isoleucine에 의해서는 그 생성이 억제되었고, tryptophan 25$\mu$g/$m\ell$ 농도의 존재하에서는 xylanase 생성이 증가했다.

• 한국미생물·생명공학회지
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• 제19권1호
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• pp.94-99
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• 1991

- The further study for the identification of the previously reported pink-pigmented facultative methylotrophic bacterium (PPFM) GL-10 was carried out. The PPFM GL-10 was Gram nagative, rod, and motile by a single polarly inserted flagellum. The colonies were smooth, pink, circular, along with convex with entire margin. The isolate could utilize C1 compounds and a variety of multicarbon substrates as sole carbon and energy source. The isolate was obligately aerobic, and exhibited both catalase and oxidase activities. The deoxyribonucleic acid base composition was 65-67 mol% guanine plus cytosine. The isolate was mostly identical with Methylobacterium extorquens and named Methylobacterium sp. strain GL-10. Methylobacterium GL-10 accumulated a copolyester of 3-hydroxybutyrate and 3-hydroxyvalerate (poly-3HB/3 HV) when grown in nitrogen-free culture media containing sodium propionate as substrate at the second polyester accumulation stage. The composition of copolyester, as determined from $^1h$ NMR spectra, was 23 mol% of 3-hydroxyvalerate (3HV).

• Journal of Microbiology and Biotechnology
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• 제8권4호
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• pp.347-352
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• 1998

A new strain of Pseudomonas aeruginosa growing in a rice field contaminated with herbicide and effluents of a factory manufacturing explosives was isolated. This isolate showed excellent growth in unusually high concentration of acrylamide (60 mM). It utilized acrylamide as the sole source of carbon and nitrogen for growth. Other amides such as acetamide, butyramide, isobutyramide, and methacrylamide were also utilized for the growth by this isolate. Acrylamide was degraded into acrylic acid and ammonia by the enzyme amidase. More than $65\%$ of added acrylamide (40 mM) was converted into acrylic acid after 40 h of growth of the culture. Amidase activity was inducible, the highest activity being observed with isobutyramide ($12.5{\mu}M$ ammonia/mg protein/min). These results demonstrate that this bacterium can degrade a variety of amides.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.843-845
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• 2005

The uncertainty of long term electricity plan consists of the uncertainty of demand forecast and additional generating capacity. Demand forecast is clearly improved the accuracy than the past through improving forecasting methods. However, the uncertainty of additional generating capacity is increased due to the change of market environment. In an operation by a sole utility, additional generating capacity would be possible by the regulation of government. Currently the generation companies have spined off from KEPCO and some IPPs participate the electricity market. It increases the uncertainty due to weakened regulation. Also the environment movement by NGOs and occurrence of civil affairs cause the increase of uncertainty. This research would analyze the current situation on the uncertainty of additional generating capacity and construction delays. Furthermore this research would present the plan to reflecting it in long term electricity plan.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.205-207
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• 2006

Since a humanoid robot inherently suffers from instability and always risks tipping itself over, or topping to the ground, it is necessary to ensure high stability and reliability of walk. An unexpected ground condition is one of the principal factors of instability. This paper proposes a walk stabilization method consisting of a Fuzzy algorithm and geometry under uneven terrain. The ground reaction forces that are measured by the FSR sensors on the sole are used to check the ground condition and the robot posture. The effectiveness of proposed method is verified by computer simulations.

• Elastomers and Composites
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• 제34권3호
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• pp.212-221
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• 1999

Mechanical properties of polypropylene filled with recycled rubber dusts obtained from the buffing process in sport shoe sole manufacture were investigated. The use of these dusts eliminates the need for the size reduction process which is usually employed in rubber recycling. Two different waxes, polypropylene wax and ethylene vinyl acetate wax, were used in the PP/rubber dust compound. Two different processes, extrusion and injection moulding, were used to study the influence of the blends on the properties. The waxes gave significant improvement in the shaping of the extrudate. It was found that the impact strength of the injection moulded samples were higher than the extruded samples and the virgin PP. The tensile properties (yield stress and modulus) were dependent on the amount of rubber dust addition. An increase in the rubber dust loading gave lower yield stress and modulus.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 1998년도 공동 심포지엄 및 추계학술발표회
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• pp.137-141
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• 1998

A chemical has been aging in soil environment is more less bioavailable than freshly added chemical. The amount of bioavailability of the aged chemical is different by bacterial strains. The difference could be depend on physiochemical properties of each strain. Phenanthrene was employed as an aged chemical. Seven bacteria were isolated from activated sludge and petroleum disposed soil. These strains were able to degrade phenanthrene and to grow using phenanthrene as a sole carbon source. According to the result of materialization and chemical extraction experiment, the bioavailable amount of aged phenanthrene which has been aged in Lima loam is different by each bacteria. Several physiochemical properties of each strain were tested to certify correlation with their different amount of bioavailability.