• Journal of Microbiology and Biotechnology
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• 제15권6호
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• pp.1221-1228
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• 2005

Carbon electrode was applied to a wastewater treatment system as biofilm media. The spatial distribution of heterotrophic bacteria in aerobic wastewater biofilm grown on carbon electrode was investigated by scanning electron microscopy, atomic force microscopy, and biomass measurement. Five volts of electric oxidation and reduction potential were charged to the carbon anode and cathode of the bioelectrochemical system, respectively, but were not charged to electrodes of a conventional system. To correlate the biofilm architecture of bacterial populations with their activity, the bacterial treatment efficiency of organic carbons was measured in the bioelectrochemical system and compared with that in the conventional system. In the SEM image, the biofilm on the anodic medium of the bioelectrochemical system looked intact and active; however, that on the carbon medium of the conventional system appeared to be shrinking or damaging. In the AFM image, the thickness of biofilm formed on the carbon medium was about two times of those on the anodic medium. The bacterial treatment efficiency of organic carbons in the bioelectrochemical system was about 1.5 times higher than that in the conventional system. Some denitrifying bacteria can metabolically oxidize $H_{2}$, coupled to reduction of $NO_{3}^{-}\;to\;N_{2}$. $H_{2}$ was produced from the cathode in the bioelectrochemical system by electrolysis of water but was not so in the conventional system. The denitrification efficiency was less than $22\%$ in the conventional system and more than $77\%$ in the bioelectrochemical system. From these results, we found that the electrochemical coupling reactions between aerobic and anaerobic reactors may be a useful tool for improvement of wastewater treatment and denitrification efficiency, without special manipulations such as bacterial growth condition control, C/N ratio (the ratio of carbon to nitrogen) control, MLSS returning, or biofilm refreshing.

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 1998년도 제1회 총회 및 추계학술발표회
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• pp.86-86
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• 1998

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 2001년도 춘계총회 및 학술발표회
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• pp.39-39
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• 2001

• 한국미생물·생명공학회지
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• 제23권5호
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• pp.519-525
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• 1995

This study was carried out to enhance the production of sisomicin by Micromonospora inyoensis ATCC 276000. The effect of various sugars and organic acids as the supplements to a basal mineral medium was tested for the sisomicin production by fully grown mycelium. Among the substances tested, acetate and citrate greatly increased the production of sisomicin at the sixth day of culture. Especially, in the basal mineral medium containing 0.1M sodium acetate, sisomicin production was 6.7 times more than that in the same medium with glucose. When 0.1M sodium acetate was added in the fermentation medium initially, the cell growth was inhibited by sodium acetate, although specific productivity was higher than that in the same medium without sodium acetate. On the contrary, when sodium acetate was added to the culture after three days, the sisomicin production and specific productivity were 1.6 times higher than those in the same medium without sodium acetate. The results suggested that sodium acetate was a stimulating substance of sisomicin production by M. inyoensis.

• KSBB Journal
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• 제25권1호
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• pp.103-107
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• 2010

Oil degradation agent was developed with organic sludge and modified peat moss (MPM) to recover oil contaminated soil. Waste sludge discharged from wastewater treatment plant of chemical plant in Ulsan National Industrial Park was used as organic sludge, and MPM was purchased. Organic sludge was adequate to use as growth medium for microorganism, the surface of MPM had porous structure which could enhance the cultivation condition of oil degradation microorganisms. Water contents and TPH variation with time were observed to investigate the degradation capacity of developed degradation agent. Water contents were rapidly decreased with higher contents of MPM, however, in case of TPH, high MPM content decreased the degradation capacity. Therefore, it was recommended that the content of MPM was controlled to below 10% in degradation agent as mixing organic sludge with MPM.

• 한국유기농업학회지
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• 제17권1호
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• pp.35-53
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• 2009

The theme-type self-harvest concept proposed in this research will be applied as a relevant reference in planning and realizing urban-rural exchange facilities at the village level. The aim of this paper is to describe the concept, to characterize the self-harvesters and organic farmers involved, to illustrate the ecological, economic and social interaction and the possible constraints of the concept. What is more important, however, is to develop programs for consultants, organic farmers and green-minded consumers, to vitalize direct transaction. The proponents of self-harvest are convinced that this concept leads to ecological, economic and social benefits, which will help to design a sustainable food supply system for small, medium and large cities.

• 한국응용과학기술학회지
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• 제9권1호
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• pp.7-13
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• 1992

Lipases catalyzed the transesterification reaction between esters and various primary and secondary alcohols in a 99% organic medium, porcine pancreatic, yeast, mold lipases can vigorously act as catalysts in a number of nearly anhydrous organic solvents. Various transesterification reactions catalyzed by porcine pancreatic lipase in hexane obey Michaelis-Menten kinetics. The dependence of the catalytic activity of the enzyme in organic media on the pH of the aqueous solution from which it was recovered is bell-shaped, with the maximum coinciding with the pH optimum of the enzymatic activity in water. The catalytic power exhibited by the lipases in organic solvents is comparable to that displayed in water. In addition to transesterification, lipases Can catalyze several other processes in organic media.

• 한국산림과학회지
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• 제101권3호
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• pp.443-453
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• 2012

본 연구는 아까시나무 유묘에서 뿌리혹 형성에 가장 적절한 배양토의 종류와 토양의 양료 수준을 구명하기 위해 수행하였다. 상업용 상토, 완숙 혹은 미숙 퇴비, 유기질 비료, 산림용 고형비료, 화학비료 등의 토양 첨가물을 이용하여 질소와 인의 수준을 다양하게 조절한 후 포트에 아까시나무 종묘를 식재하여 3개월 간 온실에서 실험을 실시하여 초기 뿌리혹 형성에 적절한 토양 환경을 조사하였다. 피트모스, 질석, 지올라이트를 함유한 상업용 상토는 높은 보수력으로 인해 초기 활착과 건중량 생산에는 적절하였으나 무기 양료 중 질소(0.052%), 인(91 ppm)의 부족으로 인해 뿌리혹 형성에는 부적합하였다. 퇴비는 미숙 퇴비이건 완숙퇴비이건 구별 없이 뿌리혹 형성에 가장 유리했는데, 질소(0.08-0.21%)와 인(141-1,228 ppm)의 함량이 적절하였지만, 칼륨(0.14-1.58 cmol/kg)의 함량은 부족한 편이었다. 화학(복합)비료는 토양 내 질소(0.14-0.21%), 인(406-618 ppm), 칼륨(1.39-3.13 cmol/kg)의 함량을 적절한 수준으로 유지하여 초기 건중량 생산에는 지장을 주지 않았지만 뿌리혹 형성에는 부적절하였다. 산림용 고형비료는 뿌리혹 형성에 적합한 반면, 유기질 비료는 뿌리혹 형성에 적합하지 않았다. 배양토에는 적절한 수준의 질소(0.05-0.2%)와 인(100-600 ppm)이 함유되어 있을 경우에 초기 뿌리혹 형성이 제대로 이뤄졌다. 아까시나무 유묘의 경우 토양의 질소와 인 중에서 질소보다 인이 초기의 뿌리혹 형성을 더 촉진하는 것으로 판단되었다.

• 한국작물학회지
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• 제45권1호
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• pp.32-37
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• 2000

The in vitro culture of rice panicles is a culturing technique only panicle without other organs in culture solution containing organic substance, so that would be useful to study how assimilate supply affects grain development and maturation. To find the optimum stage for in vitro culture, rice panicles grown in greenhouse were sampled periodically after anthesis and cultured in nutrient medium. The panicles older than 1 weeks after anthesis had produced normal grains. Grain-filling was apparently dependent upon sucrose concentration (8-12 %) in medium, but not affected by nitrogen concentration supplied with glutamine. As far as rice panicle was supplied with sucrose and N in nutrient medium, grains continued accumulation of dry matter and maturation regardless to light condition. Considerably, grain-filling was improved when panicles were positioned horizontally inside flask, so that each grain was partially submerged to nutrient medium.

• Journal of Microbiology and Biotechnology
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• 제11권1호
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• pp.56-60
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• 2001

A kerosene fungus of Cladosporium resinae NK-1 was examined for its ability to degrade individual n-alkanes and aromatic hydrocarbons by gas chromatography-mass spectrometry, and its organic solvent-tolerance was investigated by making use of the water-organic solvent suspension culture method. It grew on a wide range of solvents of varying hydrophobicities and it was found to have tolerance to various kinds of toxic organic solvents (10%, v/v) such as n-alkanes, cyclohexane, xylene, styrene, and toluene. A hydrocarbon degradation experiment indicated that NK-1 had a greater n-alkane degrading ability compared to that of the other selected strains. C. resinae NK-1, which could utilize 8-16 carbon chain-length n-alkanes of medium chain-length as a carbon source, could not assimilate the shorter chain-length n-alkanes and aromatic hydrocarbons tested so far. The n-alkane degrading enzyme activity was found in the mycelial extract of the organism.