• Korean Journal of Microbiology
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• v.51 no.4
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• pp.427-434
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• 2015

Most of halophilic archaea are found in the various hypersaline environments including solar saltern, salt lake with very high salt concentration. The present study is about isolation and characterization of halphilic archaea from Gomso solar saltern known as a representative high salt environment in Korea. In order to isolate the halophilic archaea, we prepared and used high salt medium. Finally, total 7 strains obtained were tentatively identified based on comparative similarity analysis for 16S rRNA gene sequence and physiological traits. All halophilic archaea belonged to Haloruburm, Halogeometriucm, Halobacterium, and Haloarcula genera. These isolates were all Gram-staining negative, and growth was not observed using nitrate as an alternative electron acceptor under anaerobic conditions. In addition, all isolates required about 12-30% (w/v, NaCl) salt. This case study might provide basic information on microbial isolation technologies and related research in halophilic microorganisms from domestic halophilic environments, and contribute to obtaining useful indigenous halophilic archaea in a variety of extreme environmental conditions.

• Economic and Environmental Geology
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• v.34 no.4
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• pp.345-354
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• 2001

The effects on arsenic geochemistry of indigenous microorganisms isolated from an area contaminated with high concentration of arsenic were investigated. Arsenite exerted higher inhibitory effects on the microbes' growth than arsenate. During incubation of the microbes in an arsenate-spiked medium over 24 hours, decrease in microbial growth was observed as arsenate content increased. Arsenate of 150 mM or over apparently inhibited cell growth. However, further incubation for up to 4 days in the high arsenate concentration medium resulted in cell growth, implying that the microorganisms adjusted their biochemical functions to detoxify arsenic and maintain growth. Two types of microbes were observed during 20 hours to reduce arsenate to arsenite in solution through a detoxification mechanism. As well, decrease in the total arsenic content occurred over a 4-day incubation with the same microbes in an arsenate-spiked medium. Therefore it is suggested that microorganisms can influence arsenic speciation in natural settings and this may be applied to efficient bioremediation of arsenic-contaminated sites.

• Microbiology and Biotechnology Letters
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• v.18 no.6
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• pp.624-632
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• 1990

Strain 88-GT-161 producing new phthalic acid derivative and basic macrolide antibiotics was identified as being S. melanosporofuciens based on numerical taxonomic data. However, 4 unit characters among 139 units were clearly different from the common properties of 6 strains belonging to cluster No. 32 represented by the name of S. violaceoniger or S. violaceusniger, leading us to designate as a variety of S. melunosporofaciens. This paper describes the taxonomic characteristics of the strain. Isolation and chemical structures, including biological activities of the active compounds produced by this strain will be presented elsewhere.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.8
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• pp.831-838
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• 2008

This study investigated the characteristics of nitrogen removal and microbial community in a lab-scale A$_2$O activated sludge process filled with the fluidized media at an aerebic basin. The change of microbial community was monitored based on quinone profiles of activated sludge according to feeding sewage with/without external carbon source. Low C/N ratio(COD$_{Cr}$/T-N of 1.24) sewage was fed. The obtained results from this study were as follows; Ubiquinone(UQ) in the influent was in the descending order of UQ-8, UQ-10 and UQ-9. Menaquinone(MK) was simpler and much less than UQ. The ratio of UQ/MK was less than 0.41 and the dissimilarity was below 0.26. Without an external carbon source, MK-8 was the dominant species and there were 3 kinds of quinone species and low DQ and EQ values in an anaerobic basin. The ratio of UQ/MK increased to 2.3 in an anoxic basin. In an oxic basin, UQ-7 and UQ-8 were the dominant species. UQ-7 was dominating in suspended microorganisms, while UQ-8 was in attached microorganisms. With an external carbon source addition, MK-8 decreased but UQ-8 increased in an anaerobic basin. So did quinone species, DQ and EQ values. There was also a change in an anoxic basin with the improvement of denitrification. UQ-8 decreased instead, MK-7 and MK-8 increased. UQ/MK ratio decreased 2.3 to 1.4. It means that the dominant species change from Pseudomonas sp. to Bacillus and Micrococcus species. etc. In an oxic basin, UQ-8 replaced UQ-7 in suspended microorganisms and UQ-10 replaced UQ-8 in attached microbials. This seemed related with the growth of Nitrosomonas and Nitrobactor species.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.2132-2137
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• 2009

갈대(Phragmites communis Trin.)란 염분이 있는 곳에서 자라는 염생식물로서 우리나라 전역에 분포하고 있다. 지난 50년 동안 우리나라의 여러 습지에 걸쳐서 갈대는 우점종으로 자라왔고, 육지와 수중서식지에서 갈대의 확산범위는 증가하고 있다. 갈대의 확산은 다른 습지 식물의 서식지를 파괴하고, 갈대가 번식하면 동 식물들의 번식 자체가 어려울 뿐 아니라 갈대숲에 포식자가 늘어나 살아가기 어려운 환경으로 변하기때문에 갈대를 체계적으로 관리할 수 있는 방안이 마련되어야 한다. 본 연구는 우점종이 다른 두 습지에서 갈대군집의 성장률을 관찰하고, 토양의 화학적 분석과 식물의 생리적 분석을 통해 갈대군집 성장에 미치는 영양염류의 영향을 규명하였다. 연구 대상지는 한강하구에 위치한 장항습지와 성동습지로서 동일하게 갈대가 분포하며, 장항습지에는 줄 군락이 성동습지에는 새섬매자기 군락이 우점하고 있다. 분석 항목은 이화학적 항목을 비롯하여 용존유기탄소(DOC, dissolved organic carbon), 체외미생물효소활성도(Extracellular enzyme activities), 암모니아성 질소($NH_4^+$), 질산성 질소($NO_3^-$)을 분석하였다. 실험결과, 두 습지 갈대의 성장은 7월부터 9월에 증가하였고 성동습지의 토양성분이 점토질로 형성되어 높은 수분함량과 유기물함량을 유지하고 있기 때문에 갈대의 밀도가 높고 성장률이 활발한 것으로 나타났다. 또한 미생물활성과 환경인자간 양의 상관관계를 보아 환경인자들이 미생물 활성을 자극하고 미생물들은 식물의 성장을 촉진하여 영향을 주며, 반면 식물 뿌리는 enzyme을 생성하는 미생물에게 C 삼출물을 공급해 enzyme 활성에 영향을 미칠 것으로 사료된다.

• KSBB Journal
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• v.14 no.6
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• pp.737-741
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• 1999

Phenanthrene degrading bacteria were isolated from the petroleum contaminated soil near an oil tank. Four of 15 strains decreased surface tension of culture broth of phenanthrene-containing minimal media. H6, one of the isolated bacteria decreased surface tension of culture broth below 33 dyne/cm during growth on glucose. H6 was identified as Bacillus subtilis and biosurfactant produced by H6 was lipopeptide. The biosurfactant was produced at 0.13 g/L in the mineral medium containing 2% glucose. Critical micelle concentration(CMC) of the biosurfactant was 52 mg/L. Foaming power was similar to Tween 80 and dispersing power was superior to Tween 80m SDS and Brij30. High thermal stability and emulsion index were also observed.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.4
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• pp.307-316
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• 2009

Soil microbial activity and diversity are affected by organic sources applied to improve soil quality and fluctuate seasonally. We investigated the effects of municipal compost (MC), poultry litter (PL), and cover crops of spring oats and red clover (RC) on soil enzyme activities, and soil bacterial community-level physiological profiling (CLPP) in a Mexico silt loam in North Central Missouri, USA. Temporal patterns of these parameters were observed by periodic five soil sampling from spring to fall over a two year period. MC increased soil dehydrogenase (DH) activity consistently beginning about three months after MC application; fluorescein diacetate (FDA) hydrolytic activity significantly began to increase by the September of the first year but fluctuated during the following period. DH activity responded more directly to the amount or properties of organic residues in soils while FDA hydrolysis and CLPP were generally influenced by composition of organic sources, and enzyme activities and CLPP showed seasonal variation, which depended on organic sources and soil moisture. MC and cover crops may be useful organic sources for enhancing general soil microbial activity and altering soil microbial diversity, respectively. Because microbial activities and diversity are dynamic and subject to seasonal changes, the effects of organic amendments on these parameters should be investigated frequently during a growing season.

• Economic and Environmental Geology
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• v.42 no.5
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• pp.427-434
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• 2009

Indigenous bacterium which shows a tolerance to high metal toxicity was isolated from soil concomitantly contaminated with oil and heavy metals. The characteristics of the bacterium for Pb and Cd biosorption was investigated under the various experimental conditions such as bacterial growth phase, the initial metal concentration, the input biomass amount, temperature and pH. The Langmuir adsorption isotherm modeling was described to know the capacity and intensity of biosorption. The low initial concentration of heavy metals and high biomass has a maximum heavy metal removal efficiency, but biosorption capacity of Pb and Cd has different values. Biosorption efficiency was highest in the end of the microbial growth stage and under pH 5~9 condition, but was less affected by temperature variation of 25~$35^{\circ}C$. The maximum biosorption capacity for Pb and Cd was 62.11 and 192.31 mg/g, respectively and each $R^2$ was calculated as 0.71 and 0.98 by applying Langmuir isothermal adsorption equation. Biosorption for Cd was considered as monomolecular adsorption to single layer on the surface of cells, whereas biosorption for Pb was considered as accumulation process into the cell by the microbial metabolism and precipitation reaction with anion of bacteria.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2016.10a
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• pp.251-252
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• 2016

• Microbiology and Biotechnology Letters
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• v.31 no.4
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• pp.413-420
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• 2003

To explore the effective treatment methods for waste food generating malodor compounds, mixed microorganisms (MM) capable of deodorizing of domestic animal waste were applied using household composting box. The mixture of 5 kg whole chips as a bulk agent, 2 kg MM and 1 kg of waste food were input into the compost reactor and agitated. Waste food was supplemented every 24 hours. As the results, the composting volume was stable at 13∼14 L for 10 days. In the initial compost process with MM, the pH and temperature were increased more quickly than that of without MM. Also, the conductivity recognized as a barometer of compost was increased from 0.2 to 2.4 mS/cm that was higher than 1.3 mS/cm of without MM, for 10 days. The malodor compounds generated from waste food treatment such as sulfur compounds and volatile fatty acids were effectively reduced about 90∼l00%, and 70∼80% for 8 days, respectively. The microorganisms growing under the condition of alkaline phase and higher temperature were dominated during the compost Moreover, it was demonstrated that inoculated Bacillus cereus HY15 dominated during the compost results in responsible to the effective treatment of waste food.