• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 1998년도 공동 심포지엄 및 추계학술발표회
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• pp.178-182
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• 1998

Bioremediation techniques have proved to be effective for restoring petroleum-contaminated soils. however some limitations still exist, especially biodegradation of hydrophobic organic compounds(HOCs) in soil is limited by their low solubility and sorption to solid surfaces. The principal objective of this study was to evaluate the effectiveness of biosurfactant sophorolipid on the biodegradation of hydrocarbons in soil. Experimental results showed that sophorolipid was not toxic to the HOC-degrading bacteria and enhanced biodegradation of HOCs in soil better than synthetic surfactants. when these models were treated with 1000mg/soil kg sophorolipid.

• Journal of Microbiology and Biotechnology
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• 제24권12호
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• pp.1699-1706
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• 2014

A lichenase gene (mt-lic) was identified for the first time through function-based screening of a soil metagenomic library. Its deduced amino acid sequence exhibited a high degree of homology with endo-${\beta}$-1,3-1,4-glucanase (having both lichenase and chitosanase activities), encoded by the bgc gene of Bacillus circulans WL-12. The recombinant lichenase overexpressed and purified from Escherichia coli was able to efficiently hydrolyze both barley ${\beta}$-glucan and lichenan. The enzyme showed maximal activity at a pH of 6.0 at $50^{\circ}C$, with Azo-barley-glucan as the substrate. The metal ions $Mn^{2+}$, $Mg^{2+}$, $Ca^{2+}$, and $Fe^{2+}$ enhanced the enzymatic activity, whereas the $Cu^{2+}$ and $Zn^{2+}$ ions inhibited the enzymatic activity. The $K_m$ and $V_{max}$ values of the purified lichenase were determined to be 0.45 mg/ml and 24.83 U/min/mg of protein, respectively.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.418-421
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• 2000

A model was developed to describe the microbial decontamination of diesel contaminated soil in a soil column. The biodegradation rate of diesel in nature depends on temperature and the pH of soil, availability of nutrients, oxygen and water. The soil moisture content is one of the essential factors because it characterizes the availability not only of water to microorganisms but also of oxygen and nutrient dissolved in soil. In this work, the rate of biodegradation was modeled by coupling Michaelis-Menten kinetics for the aqueous-phase solute with adsoption-desoption equation for diesel sorption and desorption from soil.

• KSBB Journal
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• 제28권5호
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• pp.275-281
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• 2013

Soil microbial community analysis of farmland soil sprayed with lye in order to use fertilizer in Nigeria was performed. As a control, two kinds of soils not sprayed with lye, located in Eungo and Lagos with general practice in agriculture was selected. Soil sprayed with lye was pH 8.25 through alkalization reaction, while the other soil samples were pH 6.22 and 5.94. Substrate utilization and species diversity index of soil sprayed with lye were low than that of the other soils with the analysis of Biolog ecoplate. As a result of principal component analysis, the relationship between three samples was low. Microbial community analysis was performed by DGGE and most of them were soil uncultured bacterium. Especially, Uncultured Acidobacteria and Uncultured Methylocystis sp., which had been isolated from the rhizosphere of soybean grown in that site were discovered in the soil sprayed with lye.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.389-389
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• 2003

• Journal of Forest and Environmental Science
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• 제24권2호
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• pp.111-118
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• 2008

산림 훼손지 비탈면 녹화에 주로 사용되는 관목류 7종에 대한 인발저항실험을 실시하였다. 조사수종의 평균인발력은 두릅나무 37.26 kgf, 버드나무 34.56 kgf, 국수나무 26.00kgf의 순으로 측정되었으며, 뿌리의 근원경 및 뿌리체적이 크면 클수록 인발력은 높게 산출되었다. 뿌리 근원경과 뿌리 체적에 대한 인발력은 산딸기나무가 가장 상관관계가 높았으며, 산초나무가 가장 낮았다. 그리고 뿌리의 근원경에 따른 인발력은 대부분 유의적인 차이가 있는 것으로 나타났으며, 뿌리체적에 따른 인발력은 뿌리체적이 20 ml미만에서만 수종간의 인발력 차이가 있는 것으로 나타났다.

• Journal of Microbiology and Biotechnology
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• 제32권2호
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• pp.176-186
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• 2022

Continued fenvalerate use has caused serious environmental pollution and requires large-scale remediation. Dibutyl phthalate (DBP) was discovered in fenvalerate metabolites degraded by Citrobacter freundii CD-9. Coculturing is an effective method for bioremediation, but few studies have analyzed the degradation pathways and potential mechanisms of cocultures. Here, a DBP-degrading strain (BDBP 071) was isolated from soil contaminated with pyrethroid pesticides (PPs) and identified as Stenotrophomonas acidaminiphila. The optimum conditions for DBP degradation were determined by response surface methodology (RSM) analysis to be 30.9 mg/l DBP concentration, pH 7.5, at a culture temperature of 37.2℃. Under the optimized conditions, approximately 88% of DBP was degraded within 48 h and five metabolites were detected. Coculturing C. freundii CD-9 and S. acidaminiphila BDBP 071 promoted fenvalerate degradation. When CD-9 was cultured for 16 h before adding BDBP 071, the strain inoculation ratio was 5:5 (v/v), fenvalerate concentration was 75.0 mg/l, fenvalerate was degraded to 84.37 ± 1.25%, and DBP level was reduced by 5.21 mg/l. In addition, 12 fenvalerate metabolites were identified and a pathway for fenvalerate degradation by the cocultured strains was proposed. These results provide theoretical data for further exploration of the mechanisms used by this coculture system to degrade fenvalerate and DBP, and also offer a promising method for effective bioremediation of PPs and their related metabolites in polluted environments.

• KSBB Journal
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• 제4권1호
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• pp.8-10
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• 1989

불순응된 사질토에서 7,12 - 이메틸벤조안트라쎈 돌연변이 유발성의 불활성화에 대한 연구가 행해졌다. 토양에서 형성된 이메틸벤조아트라센의 극성이 강한 대사산물은 Ames분석에서 돌연변이성을 나타내지 않았다. 극성이 중간 또는 약한 대사산물은 돌연변이성을 보였으며, 그 변이비는 모체화합물의 변이비와 유사하였다.

• Journal of Microbiology and Biotechnology
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• 제14권2호
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• pp.337-343
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• 2004

A bacterial strain concurrently producing extracellular chitosanase and chitinase was isolated from soil and identified as a member of the $\beta$-subgroup of Proteobacteria through its 16S rRNA analysis and some biochemical analyses. The newly discovered strain, named as KNU3, had 99% homology of its 16S rRNA sequence with chitinolytic $\beta$-Proteobacterium CTE108. Strain KNU3 produced 34 kDa of chitosanase in addition to two chitinases of 68 kDa and 30 kDa, respectively. The purified chitosanase protein (ChoK) showed activity toward soluble, colloidal, and glycol chitosan, but did not exhibit any activity toward colloidal chitin. The optimum pH and temperature of ChoK were 6.0 and $70^{\circ}C$, respectively. The chitosanase was stable in the pH 4.0 to 8.0 range at $70^{\circ}C$, while enzyme activity was relatively stable at below $45^{\circ}C$. MALDI-TOF MS and N-terminal amino acid sequence analyses indicated that ChoK protein is related to chitosanases from Matsuebacter sp. and Sphingobacterium multivorum. HPLC analysis of chitosan lysates revealed that glucosamine tetramers and hexamers were the major products of hydrolysis.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2004년도 학술대회지
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• pp.107-125
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• 2004

A bioremediation of petroleum-contaminated soil in Korea was evaluated for the optimization of enhanced biodegradation and the minimization of effects of seasonal variations, The short-term bioremediation in combination of biopile pretreatment and landfarming was performed by lowering contaminated levels and overcoming the inhibiting factors in the rainy and winter seasons. A microbial density was maintained with indigenous microbial addition for bioaugmentation and with fertilizers for biostimulation. A lesser volatile and biodegradable fraction due to their abiotic removals following the biopile pretreatment was effectively removed by the laterally applied landfarming. The optimal temperature in greenhouse was maintained by buffering of the soil temperature even with slight decreases in removal rates during the winter and extensive leaching of nutrients and contaminants was restricted with adjusting the water contents during the Korean rainy season. Although the tilling process was effective for biodegradation with aeration only, the simultaneous treatment due to apparent mixing of nutrients and microbes more favorably degraded the petroleum than the sequential treatment.