• Korean Journal of Microbiology
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• v.49 no.4
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• pp.353-359
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• 2013

The objectives of this study were to investigate effectiveness of the Compressed Air Jet (CAJ) System for cleaning up shorelines contaminated with crude oils and to examine effects of the system on total petroleum hydrocarbon (TPH) removal and microbial community changes before and after remediation of the oil-contaminated shorelines. These data will lead to better understanding of optimized remediation process. About 66% of TPH reduction was observed when the contaminated site was treated with the CAJ System 2, 3, 4, and 5 times. This treatment system was more efficient than the seawater pumping system under similar treatment conditions (by 40%). By the way, little oil degrader communities were observed despite a potential function of the air jet system to stimulate aerobic oil degraders. The apparent low population density of the oil degraders might be as a result of low concentration of TPH as a carbon source and limiting nutrients such as nitrogen and phosphorus. It was proposed that the CAJ System would contribute significantly to removal of residual oils on the shorelines in combination with addition of these limiting nutrients.

• Journal of Life Science
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• v.24 no.5
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• pp.543-548
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• 2014

Aquifer recharge and recovery is a technology used to ensure a stable supply of clean water. During the process, river water is injected into a soil aquifer and stored. The stored water is then recovered and used to produce drinking water. It is important to understand quality improvement of the injected water while it is stored in the aquifer. In the present study, a lab-scale column reactor containing saturated-zone soil was employed to mimic an aquifer. The reactor was used to investigate microbial removal of nitrate that is a major inorganic contaminant detected in the Nakdong River. The reactor was introduced with river water that contained nitrate at concentrations (5.07, 6.81, 8.27, and 11.07 mg $NO_3{^-}/l$) detected downstream of the Nakdong River in the past 2 years. The nitrate concentrations decreased during the introduced water is retained in the reactor. Effluent from the reactor contained 1.49 mg $NO_3{^-}/l$ or less and had an average pH of 7.98 regardless of the nitrate concentrations of the influent. However abiotic control reactor showed similar nitrate-concentrations in its influent and effluent. Considering the result of abiotic control, the decreased nitrate concentration observed in the test column suggested that microorganisms in saturated-zone soil removed nitrate in the river water introduced into the reactor. Results of this study will be used to better understand microbial improvement of water quality in aquifer recharge and recovery technology.

• Journal of Wetlands Research
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• v.14 no.4
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• pp.489-502
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• 2012

Biogeochemical processes in groundwater-stream water mixing zone are recently of great interest because biodegradation and natural attenuation of aquatic contaminants may occur through the processes. The objectives of this study are to investigate the hydrologic and biogeochemical processes at the groundwater-stream water mixing zone through which surface water-driven nitrate may be naturally attenuated, and to examine the effect of the vertical flow exchange flux on biogeochemical processes using correlation analysis. To examine the direction of vertical water flow in the zone, vertical hydraulic gradients were measured at several depths using mini-piezometers. Microbial populations in soil samples of the zone were also analyzed by means of the polymerase chain reaction (PCR) and Cloning methods. In addition, partial correlations among vertical flow exchange, nitrate concentration and microbial activity was investigated to examine their mutual interaction. The results showed the significant interaction among the three parameters, resulting in natural attenuation of nitrate. This study showed an example of the biogeochemical fuction of groundwater-stream water mixing zone, which can be predictable from the examination of the interaction among microbial activities, concentration of contamination and vertical flow exchange flux. temperature show a significant difference in adjacent streambed, Also, the results shows that distribution of temperature was more affected by groundwater direction than intensity of flux.

• Microbiology and Biotechnology Letters
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• v.42 no.4
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• pp.377-385
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• 2014

In this study, a wastewater treatment system for hypersaline wastewater utilizing the Hypersaline Wastewater Treatment Community (HWTC) has been developed. The hypersaline wastewater treatment efficiency and microbial community of the HWTC were investigated. The average removal efficiencies of chemical oxygen demand were 84% in an HRT of 2.5 days. Microbial community analysis, by denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rRNA gene fragments and 16S rRNA gene clone library, revealed community diversity. The 16S rRNA gene analysis of dominant microbial bacteria in 4% hypersaline wastewater confirmed the presence of Halomonas sp. and Paenibacillus sp. Phylogenetic analysis suggested that the taxonomic affiliation of the dominant species in the HWTC was ${\gamma}$-proteobacteria and firmicutes. These results indicate the possibility that an appropriate hypersaline wastewater treatment system can be designed using acclimated sludge with a halophilic community.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1976.10a
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• pp.188.1-188
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• 1976

주유소, 공장주변의 하수 및 토양으로부터 Methanol 자화성 효모 7주를 분리하고 그중 생육이 왕성한 균주 2주에 대하여 동정을 행한즉 양주, 모두 Candida속에 속하는 것으로 추정되었다. 양주는 모두 ethanol 자화성을 가지고 생육에는 Biotin을 요구하였다. 배양특성은 최적온도 $28^{\circ}C,$ 최적 pH4~5이고 methanol 농도 1% v/v에서 증식이 양호하였고, 균체수율은 대소비 methanol에 대하여 30~40%에 달하였다.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1979.10a
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• pp.245.1-245
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• 1979

PDP 전자 계산기를 발효소에 연결하여 자동 제어하의 효모 유가 배양을 수행하였다. 필요한 부대 장치들을 만들어 성공적으로 사용하고 feed-back자동 제어를 수행할 수 있게 발효도중 임의의 시간에 발효 조건을 모니터하도록 하였다. 연속 세포 농도 측정을 위한 플로우ㆍ셀을 자체 제작하여 사용함과 동시에 기포 제거를 따로 할 필요가 없도록 하였다. 측정 시그날을 위한 증푹기도 자체 제작하였던 바 우수한 성능을 보여 주었다. 이 경험으로 다른 모든 측정 장치의 개발과 전자 계산기에의 연결에 값진 경험을 주었다.

• Microbiology and Biotechnology Letters
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• v.20 no.4
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• pp.470-476
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• 1992

Upon lyophilization of Nocardia mediterranei, the effects of cryoprotectants, cell concentration and drying time on viability were examined, The data were treated by computer according to response surface analysis. As a result, the maximum value of presumed viability was 39.3% under the optimal conditions of 1l.6%(v/v) sucrose, $1.16{\times}10^{11}$(CFU/ml) cell concentration, and drying time for 6.18 hrs. We also used the starter cell of rehydrated solution after lyophilization in industrial production, obtained the fermentation pattern and the purity of rifamycin B which were the same with control (FVM) and it is possible for us to use N mediterranei as a starter cell after the storage of lyophilization for 18 months.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.1107-1111
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• 2000

마두령 추출물로부터 항균활성물질을 분리하여 천연항균제로서 이용하고자 식품의 부패 및 식중독과 관계는 미생물에 대한 항균력을 측정한 결과, Gram(+), Gram(-) bacteria, yeast, mold 등 다양한 균주에 대하여 우수한 항균력을 보이며 농도에 비례하여 항균력이 증가하였고, 최소 농도 100ppm에서 미생물 생육저해효과를 보였고, 500ppm의 농도에서 새육이 완전히 억제 되는 것을 볼 수 있었다. 마두령 추출물의 열 및 pH 안정성 실험결과, 다양한 범위의 온도(4$0^{\circ}C$~15$0^{\circ}C$) 및 pH(4~10) 범위에 관계없이 동일한 항균력을 보여 열과 pH에서도 안정함을 알 수 있었다.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.04a
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• pp.198-201
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• 2001

In-situ flushing의 적용에 따른 농도 저감이 생물학적 분해에 미치는 영향을 알아보기 위하여, 초기농도 13mg/kg dry soil과 3mg/kg dry soil인 토양을 생물학적으로 처리한 결과 제거효율은 각각 86% 및 81%였으며, 두 가지 토양 모두 24시간 이후에는 미생물에 의한 작용이 크지 않은 것으로 나타났다. 이것은 토양상에서 용액상으로의 미생물에 의한 작용이 크지 않은 것으로 나타났다. 이것은 토양상에서 용액상으로의 물질전이 속도가 율속 단계로 작용하고 있기 때문이라 생각된다. 토양에 잔류하는 계면활성제가 생물학적 분해에 미치는 영향을 본 결과, 잔류하는 계면활성제에 의해 물질전이 속도가 향상되어 생분해가 지속적으로 일어났으며 초기농도 3mg/kg dry soil인 경우 120시간이 경과한 후 89%의 제거효율을 나타내었다. 계면활성제와 보조용매가 동시에 잔류하는 경우에는 계면활성제에 대한 순응기간이 보다 길어지는 것을 알 수 있었으며, 메탄올과 에탄올의 경우 각각 84%의 제거효율을 나타내었다.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11b
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• pp.49-50
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• 2003

본 실험은 An-Ax 조건에서 $NO_3$ loading에 변화를 주면서 DNPAOs의 존재 유무를 확인하고 과연 이 미생물이 무산소조에서 이 PHA를 탄소원으로 인섭취를 할 수 있는지의 여부를 조사하고자 수행하였다. 유입 $NO_3$농도에 따라 전체를 4개의 case로 분류하여 실험을 수행하였다. case I에서는 인섭취가 43.68 mg/day로 거의 일어나지 않았는데 이는 전자수용체로서 $NO_3$가 부족했기 때문 이였다. 다음 caseII에서는 333.36 mg/day로 인섭취량이 많이 증가하였고 case III, IV에서는 각각 447.48, 428.64 mg/day로 거의 일정해졌다. 이를 통해 전자수용체로 $NO_3$를 이용하는 DNPAOs가 존재함을 분명히 알 수 있었고 또한 이 미생물이 최적으로 P 섭취를 할 수 있는 유입 $NO_3$농도는 본 실험 조건에서 는 20mg/L였다.