• Journal of Microbiology and Biotechnology
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• 제1권1호
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• pp.1-5
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• 1991

Sulfate-reducing bacteria have been isolated from soil and their abilities to degrade dibenzothiophene (DBT) were compared with those of type cultures. Among the strains tested a soil isolate M6 showed the highest ability to degrade DBT. Isolate M6 was characterized as a mesophilic obligatory anaerobe. The morphology of the bacterium was vibrioid with the size of $0.4-0.7{\;}\mu\textrm{m}{\;}by{\;}1.0-1.5{\;}\mu\textrm{m}$. Gram reaction was negative and nonsporulating. Desulfoviridin is present. Lactate, pyruvate, ethanol and malate supported growth of the bacterium in the presence of sulfate. Sulfate, sulfite, thiosulfate and sulfur served as electron acceptors for growth. Hydrogenase was present. The mol% of guanine and cytosine of DNA was determined as 56%. The bacterium produced viscous material. From these results, the isolate M6 was identified as Desulfovibrio desulfuricans.

• 한국미생물·생명공학회지
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• 제24권2호
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• pp.160-165
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• 1996

An alkalophilic bacterium producing alkaline protease(s) was isolated from soil. It was a Gram-positive, non-sporulating, immotile, irregular rod, strictly aerobic, and weak acid-forming bacterium. The morphological, physiological, and biochemical characteristics of the isolate resembled those of the Coryneform bacteria. However, there was not any species within this genera to which this microorganism can be closely matched. Therefore, it is provisionally identified as a Coryneform bacterium TU-19.

• 한국미생물·생명공학회지
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• 제21권6호
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• pp.577-581
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• 1993

The amino acid threonine was produced from glycine and ethanol in a reaction mixture using cell free extract of the methylotrophic bacterium isolated from soil and identified as mellthylo-bacterium sp. KJ29. Although the isolate could grow on carbon source other than methanol, only the cell free extract from the cells grown on methanol produced threonine. Methanol dehydrogenase (MDH) activity was present only in the cells grown on methanol when compared to the cells grown on heterotrophic substrates.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2001년도 Proceedings of the 3rd Annual Meeting of Yellow Sea Environment
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• pp.11-16
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• 2001

If microorganisms are injected into porous medium such as soils along with appropriate substrate and nutrients, soil pore size and shape are changed from the initial condition as a result of biofilm formation, which make hydraulic conductivity reduced. In this research, hydraulic conductivity reduction was measured after specific bacterium or fungus was inoculated into soil pore. Hydraulic conductivity was decreased to 10 % ∼ 1 % and maintained constant while substrate was provided. Under the adverse conditions such as no substrate, chemical solution permeation, and freeze-thaw cycles, hydraulic conductivity was increased 30∼50%. Hydraulic conductivity decrease of fungus-soil mixture was faster than that of bacterium-soil mixture. Fungus-soil mixture, however, was more sensitive to the adverse conditions.

• Journal of Microbiology and Biotechnology
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• 제23권11호
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• pp.1617-1626
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• 2013

The Bacterial community structure and its complexity of the enrichment culture during the isolation and screening of imidacloprid-degrading strain were studied using denaturating gradient gel electrophoresis analysis. The dominant bacteria in the original tea rhizosphere soil were uncultured bacteria, Rhizobium sp., Sinorhizobium, Ochrobactrum sp., Alcaligenes, Bacillus sp., Bacterium, Klebsiella sp., and Ensifer adhaerens. The bacterial community structure was altered extensively and its complexity reduced during the enrichment process, and four culturable bacteria, Ochrobactrum sp., Rhizobium sp., Geobacillus stearothermophilus, and Alcaligenes faecalis, remained in the final enrichment. Only one indigenous strain, BCL-1, with imidacloprid-degrading potential, was isolated from the sixth enrichment culture. This isolate was a gram-negative rod-shaped bacterium and identified as the genus Ochrobactrum based on its morphological, physiological, and biochemical properties and its 16S rRNA gene sequence. The degradation test showed that approximately 67.67% of the imidacloprid (50 mg/l) was degraded within 48 h by strain BCL-1. The optimum conditions for degradation were a pH of 8 and $30^{\circ}C$. The simulation of imidacloprid bioremediation by strain BCL-1 in soil demonstrated that the best performance in situ (tea soil) resulted in the degradation of 92.44% of the imidacloprid (100 mg/g) within 20 days, which was better than those observed in the ex situ simulations that were 64.66% (cabbage soil), 41.15% (potato soil), and 54.15% (tomato soil).

• Journal of Ginseng Research
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• 제25권1호
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• pp.53-58
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• 2001

적변삼과 건전삼 그리고 이들의 근권토양으로부터 분리한 토양세균과 적변현상과의 관계를 구명하고자 pH 변화와 철 이온에 따른 토양세균의 생장 특성을 조사한 결과, 분리된 모든 토양세균은 pH 3.0에서는 생장하지 못하였다. 그러나 RCG와 RCS는 2 mM Fe$^{3+}$ 가 포함된 배지에서는 pH 3.0에서도 생장하였다. 특히, RCG의 경우는 철이 포함된 배지에서는 철이 없는 배지보다 생장이 2배 정도 높았다. 적변삼의 뿌리에서 분리된 토양세균(RCG)은 pH 5.0에서 pH 9.0사이에서는 생장에 큰 차이가 없었으나, 건전삼의 근권토양에서 분리된 토양세균(HES)은 다른 곳에서 분리된 세균에 비해 생장이 낮았다. 적변삼의 근권토양에서 분리한 토양세균(RCS)과 표토에서 분리한 토양세균(SUS)의 생장은 pH5.0에서 pH 7.0과 pH 9.0에 비해 다소 낮았다. 분리된 모든 토양세균의 cellulase효소활성은 철이온이 포함된 배지에서 철이온이 없는 배지보다 2배 이상 높게 나타났다. 세포 외효소 활성은 세포 내 효소 활성보다 약 10 이상 높았고, pH5.0에서 RCS의 효소활성은 pH 7.0 보다 2배 이상 높았다. 특히, 2 mM Fe$^{3+}$ 가 포함된 배지에서 RCS의 세포 내 효소활성은 철이온이 없는 배지보다 6~7배 높았고 세포 외 효소의 경우에는 11~12배가 증가되었다. 이러한 결과는 인삼의 적변현상과 관련된 토양세균은 철이온의 산화환원과cellulase분비에 의한 세포벽 분해 그리고 인삼 표피세포에 철이온과 강력한 리간드를 형성하는 것으로 판단된다.

• 한국미생물·생명공학회지
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• 제38권3호
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• pp.335-339
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• 2010

본 연구에서는 디젤로 오염된 토양에서 디젤 분해능이 우수한 Gordonia sp. SD8을 분리하였고, 이 균주의 디젤 분해특성을 액상과 토양에서 조사하였다. SD8은 유일 에너지원과 탄소원으로 디젤을 이용하여 생장 가능하였다. SD8 균주의 성장과 디젤 분해속도에 미치는 디젤 농도 영향을 조사한 결과, 20,000 mg-TPH $L^{-1}$농도에서 최대 비성장속도($0.67{\pm}0.05\;d^{-1}$)와 최대분해속도($1,727{\pm}145$ mg-TPH $L^{-1}\;d^{-1}$)를 얻을 수 있었다. 또한, 이 균주는 40,000 mg-TPH $L^{-1}$의 고농도 디젤을 분해할 수 있었으며, $30^{\circ}C$에서 비성장속도와 디젤분해속도가 가장 빨랐다. 디젤로 오염된 토양 정화에 미치는 Gordonia sp. SD8 접종 효과를 조사한 결과, 17일 경과 후, SD8을 접종하지 않은 대조군 토양의 디젤 잔류 농도는 $8,150{\pm}755$ mg-TPH kg-dry $soil^{-1}$이었으나, SD8을 접종한 경우에는 3,724 mg-TPH kg-dry $soil^{-1}$이었다. 이러한 결과는 Gordonia sp. SD8는 향후 디젤 등을 포함한 석유계 탄화수소화합물로 오염된 토양을 정화하는데 활용 가능한 유용 미생물 자원임을 의미한다.

• 한국토양비료학회지
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• 제44권1호
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• pp.112-117
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• 2011

A strain of phosphate solubilizing bacterium was isolated from rhizosphere and identified as Burkholderia sp. by 16S-rRNA gene sequence analyses. The bacterium was found to release gluconic acid and the solubilization of hydroxyapatite in the liquid medium by a significant drop in pH to 3.7 from an initial pH 7.0. The soluble-P concentration continuously increased during the incubation periods and the total amount of soluble P released in culture filtrate was detected at 990 mg $L^{-1}$ after 10 days of inoculation. Most promoted maize growth was found in the standard NPK (240-120-120 kg $ha^{-1}$) soil inoculation with Burkholderia sp. (Twenty milliliters/plant, 106 CFU) and also in the absence of Burkholderia sp. inoculation, the soil amended with only 2/3 levels of P gave significant higher plant yield compared to 1/3 levels of P or without P supplementation.

• Journal of Microbiology
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• 제39권2호
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• pp.139-141
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• 2001

Medium-chain length polyhydrexyalkanoic acids (MCL-PHAs) degrading bacterium was isolated from the soil. The bacterium was identified as Janthinobacterium lividum by its biochemical properties, cell membrane fatty acids composition, and 16S rDNA sequence analysis. The bacterium showed a similarity of 0.911 with J. lividum according to the cell membrane fatty acids analysis and a similarity of 97% in the 16S rDNA requence analysis. Culture supernatant of the bacterium skewed the highest depolymerase activity toward polyhydroxynonanoic acid (PHN) that did not degrade the poly-$\beta$-hydroxybutyric acid (PHB). The esterase activity was also detected with p-nitrophenyl (PNP) esters of fatty acids such as PNP-dodecanoic PNP-dodecanoic acid, PNP-decanoic acid, and PNP-hexanoic acid.

• 한국환경과학회지
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• 제19권11호
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• pp.1391-1396
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• 2010

Three biphenyl-degrading microorganisms were isolated from polluted soil samples in Sasang-gu, Busan. Among them, isolate DS-94 showing the strong degrading activity was selected. The morphological, physiological, and biochemical characteristics of DS-94 were investigated by API 20NE and other tests. This bacterium was identified as the genus Pseudomonas by 16S rDNA sequencing and designated as Pseudomonas sp. DS-94. The optimum temperature and pH for the growth of Pseudomonas sp. DS-94 were $25^{\circ}C$ and pH 7.0, respectively. This isolate could utilize biphenyl as sole source of carbon and energy. Biphenyl-degrading efficiency of this isolate was measured by HPLC analysis. As a result of biological biphenyl-degradation at high biphenyl concentration (500 mg/L), biphenyl-removal efficiency by this isolate was 73.5% for 7 days.