• 한국환경과학회지
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• 제8권4호
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• pp.451-456
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• 1999

Microorganisms utilizing petroleum as substrate were screened from the seawater in Pusan coastal area. Among them, fifty strains utilized bunker-A oil as a sole carbon and energy source. Five of these fifty strains were selected to experiment this study. According to the taxonomic characteristics of its morphological, cultural and biochemical properties, the selected stains were named Pseudomonas sp. EL-12, Flavobacterium sp. EL-15, Acinetobacter sp. EL-18, Enterobacter sp. EL-27 and Micrococcus sp. EL-43, respectively. The optimal medium compositions and cultural conditions for assimilation of bunker-A oil by the selected strains were 1.5-2% bunker-A oil, 0.1% $NH_4NO_3$, 1-1.5% $MgSO_4$.$7H_2O$, 0.05-0.15% KCl, 0.1-0.15% $CaCl_2$.$2H_2O$, 2.5-3.5% NaCl, initial pH 8-9, temperature 3$0^{\circ}C$ and aeration, respectively. The utilization and degradation characteristics on the various hydrocarbons by the selected stains were showed that bunker oil, n-alkane and branched alkane compounds were highly activity than cyclic alkane and aromatic hydrocarbon compounds.

• Journal of Microbiology and Biotechnology
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• 제17권6호
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• pp.1054-1057
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• 2007

Lipases are industrially useful versatile enzymes that catalyze numerous different reactions including hydrolysis of triglycerides, transesterification, and chiral synthesis of esters under natural conditions. Although lipases from various sources have been widely used in industrial applications, such as in food, chemical, pharmaceutical, and detergent industries, there are still substantial current interests in developing new microbial lipases, specifically those functioning in abnormal conditions. We screened 17 lipase-producing yeast strains, which were prescreened for substrate specificity of lipase from more than 500 yeast strains from the Agricultural Research Service Culture Collection (Peoria, IL, U.S.A.), and selected Yarrowia lipolytica NRRL Y-2178 as a best lipase producer. This report presents new finding and optimal production of a novel extracellular alkaline lipase from Y. lipolytica NRRL Y-2178. Optimal culture conditions for lipase production by Y. lipolytica NRRL Y-2178 were 72 h incubation time, $27.5^{\circ}C$, pH 9.0. Glycerol and glucose were efficiently used as the most efficient carbon sources, and a combination of yeast extract and peptone was a good nitrogen source for lipase production by Y. lipolytica NRRL Y-2178. These results suggested that Y. lipolytica NRRL Y-2178 shows good industrial potential as a new alkaline lipase producer.

• 한국토양비료학회지
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• 제49권2호
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• pp.144-156
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• 2016

Soil is a dynamic biological system, in which it is difficult to determine the composition of microbial communities. Knowledge of microbial diversity and function in soils are limited because of the taxonomic and methodological limitations associated with studying the organisms. In this review, approaches to measure microbial diversity in soil were discussed. Research on soil microbes can be categorized as structural diversity, functional diversity and genetic diversity studies, and these include cultivation based and cultivation independent methods. Cultivation independent technique to evaluate soil structural diversity include different techniques such as Phospholipid Fatty Acids (PLFA) and Fatty Acid Methyl Ester (FAME) analysis. Carbon source utilization pattern of soil microorganisms by Community Level Physiological Profiling (CLPP), catabolic responses by Substrate Induced Respiration technique (SIR) and soil microbial enzyme activities are discussed. Genetic diversity of soil microorganisms using molecular techniques such as 16S rDNA analysis Denaturing Gradient Gel Electrophoresis (DGGE) / Temperature Gradient Gel Electrophoresis (TGGE), Terminal Restriction Fragment Length Polymorphism (T-RFLP), Single Strand Conformation Polymorphism (SSCP), Restriction Fragment Length Polymorphism (RFLP) / Amplified Ribosomal DNA Restriction Analysis (ARDRA) and Ribosomal Intergenic Spacer Analysis (RISA) are also discussed. The chapter ends with a final conclusion on the advantages and disadvantages of different techniques and advances in molecular techniques to study the soil microbial diversity.

• 공업화학
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• 제3권1호
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• pp.1-6
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• 1992

메탄올은 저급(低級) 탄소원(炭素源)의 활용(活用)이란 측면(側面)에서, 에너지 저장(貯藏) 운송(運送)이란 관점(觀點)에서 점점 관심(關心)을 끌고 있다. 특히 저급탄소원(低級炭素源)으로부터의 메탄올 합성기술(合成技術)은 이미 상업화(商業化)되어 있는 기술(技術)이기 때문에 더욱 현실적(現實的)인 기술(技術)로 대두되고 있다. 메탄올은 발전(發電), 도시(都市)가스, 화학원료(化學原料) 및 운송연료(運送燃料)로 저급(低級) 탄소원(炭素源)을 활용(活用)할 경우(境遇), 상호(相互) 연계(連繫)하는 매개체(媒介體)로 사용(使用)할 수 있으므로 이를 국익(國益) 차원(次元)에서 C1화학(化學) 기술(技術)을 통한 연계방안(連繫方案)을 기술(技術)하려고 시도하였다. 특히 이산화탄소(二酸化炭素)를 자연계(自然界)에서처럼 일종(一種)의 수소저장(水素貯藏) 수단(手段)으로 메탄올 합성(合成)에 이용(利用)함으로 지구온난화(地球溫暖化) 같은 환경문제(環境問題)를 줄이는 방안(方案)으로 제시(提示)했다.

• Journal of Species Research
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• 제4권2호
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• pp.127-136
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• 2015

As an outcome of the study on the bacterial species diversity in Korea, we report 24 unrecorded bacterial species of Korea belonging to the phylum Firmicutes. The unrecorded species excavated through this study were assigned to 12 different genera of 7 families, namely Bacillus, Halobacillus, Lysinibacillus and Thalassobacillus of Bacillaceae, Brevibacillus and Paenibacillus of Paenibacillaceae, Viridibacillus of Planococcaceae, Salinicoccus and Staphylococcus of Staphylococcaceae, Enterococcus of Enterococcaceae, Lactobacillus of Lactobacillaceae, and Lactococcus of Streptococcaceae, respectively. The bacterial isolates were obtained from various ecosystems in Korea. The isolates were identified based on 16S rRNA gene sequences, and those exhibiting at least 99% sequence similarity with known bacterial species but never reported in Korea were selected as unrecorded species. The selected isolates were subjected to further taxonomic characterization including the analysis of cell shape and fine structure using electron microscope, colony color and shapes, enzyme activities and carbon source utilization. The descriptive information on the 24 unrecorded species are provided.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2005년도 2005 Annual Meeting & International Symposium
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• pp.245-247
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• 2005

A cellulolytic fungus isolated from Agave plantation in northeastern Thailand was identified as Acrophialophora nainiana. The fungus was capable of growing at pH between 3 - 7 and 25 - 45 $^{\circ}C$, with the optimum conditions at pH 5.0 and 40 $^{\circ}C$. The wild isolate produced cellulases, comprising of exoglucanase (0.019 U/mg protein), endoglucanase (0.366 U/mg protein), and ${\beta}$-glucosidase (0.001 U/mg protein). Mutations with UV and NTG produced the UV 10-2 mutant with cellulases activities including exoglucanase (0.093 U/mg protein), endoglucanase (0.585 U/mg protein), and ${\beta}$-glucosidase (0.013 U/mg protein). Purification of the enzymes with ultrafiltration, ammonium sulfate precipitation, and ion-exchange chromatography yielded the maximal cellulase specific activities of 2.736 U/mg protein (exoglucanase), 0.235 U/mg protein (endoglucanase), and 0.008 U/mg protein (${\beta}$-glucosidase). The mutant's cellulases were the most active at pH 5.0 and 60 $^{\circ}C$. Ion-exchange chromatography revealed that A. nainiana UV 10-2 cellulases were comprised of two peaks with one peak showing the single endoglucanase activity while the other peak showed a mixture of the three enzyme activities. Production of A. nainiana UV 10-2 cellulases using banana leaf stalk as the sole carbon source gave comparable yields to that of the pure ${\alpha}$-cellulose. The enzymes were used in the simultaneous saccharification and fermentation (SSF) of plant residue (Coix aquatica) along with Kluveromyces marxianus to produce ethanol. Moreover, when the enzymes were used in the bioscouring process of fabric, the desiravle traits of textile processing including immediate water absorbency, increased in whiteness and reduction of yellowness of the treated fabric were observed.

• 한국미생물·생명공학회지
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• 제5권3호
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• pp.119-125
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• 1977

섬유소 단세프 단백질의 대량생산 시험을 위하여 pilot plant 규모의 시험공장 연구를 수행하였는바 그 결과를 요약하면 다음과 같다. 1) 시험공장에서 균체생산을 위한 최적 조건을 pH 7.4, 온도 34$^{\circ}C$, 교반량 130rpm, 통기량 0.4~0.6VVM이었다. 2) 최적배양 조건에서 배지의 적정 수준은 기질로서 볏짚이 4%, (NH$_4$)$_2$SO$_4$0.2%, $K_2$HPO$_4$0.05%, KH$_2$PO$_4$0.10%, NaCl 0.2%, MgSO$_4$ㆍ7$H_2O$ 0.01%, CaCl$_2$ㆍ2$H_2O$ 0.01%, C. S. L. 0.02%였다.

• 공업화학
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• 제23권3호
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• pp.333-338
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• 2012

본 연구에서는 비성형 RDF의 에너지 활용성을 확인하기 위하여 실험실 연소로를 이용한 온도 변화에 의한 연소특성연구를 하였다. 비성형 RDF 연소시 배출가스의 특성과 분진 및 잔류물을 분석하였으며 또한 그 결과를 성형 RDF의 연소실험 결과와 비교분석하였다. 본 연구로부터 비성형 RDF가 성형 RDF에 비교하여 연소속도가 빨라져서 급격히 산소량이 감소되어 불완전연소율이 증가함을 확인하였다. 또한 연소온도가 높아질수록 연소속도가 향상되었으며 산소 소모량이 급격히 증가하였고, 이에 따른 불완전연소율이 증가하여 CO의 농도가 높아짐을 알 수 있었다. 따라서 비성형 RDF의 완전연소를 위한 운전조건의 설정에 매우 신중을 기해야 할 것으로 판단되었다.

• Journal of Microbiology and Biotechnology
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• 제20권10호
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• pp.1440-1445
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• 2010

Rhodococcus sp. JDC-11, capable of utilizing di-n-butyl phthalate (DBP) as the sole source of carbon and energy, was isolated from sewage sludge and confirmed mainly based on 16S rRNA gene sequence analysis. The optimum pH, temperature, and agitation rate for DBP degradation by Rhodococcus sp. JDC-11 were 8.0, $30^{\circ}C$, and 175 rpm, respectively. In addition, low concentrations of glucose were found to inhibit the degradation of DBP, whereas high concentrations of glucose increased its degradation. Meanwhile, a substrate utilization test showed that JDC-11 was also able to utilize other phthalates. The major metabolites of DBP degradation were identified as monobutyl phthalate and phthalic acid by gas chromatography-mass spectrometry, allowing speculation on the tentative metabolic pathway of DBP degradation by Rhodococcus sp. JDC-11. Using a set of new degenerate primers, a partial sequence of the 3,4-phthalate dioxygenase gene was obtained from JDC-11. Moreover, a sequence analysis revealed that the phthalate dioxygenase gene of JDC-11 was highly homologous to the large subunit of the phthalate dioxygenase from Rhodococcus coprophilus strain G9.

• 한국지반환경공학회 논문집
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• 제9권2호
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• pp.23-29
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• 2008

고농도 입자성 유기 폐수를 대상으로 기존 혐기성 공정인 CSTR과 UASB공정으로 처리 시 불량한 상징수질, 불안정한 운전 특성과 같은 문제점이 제시되었다. 이에 본 연구는 새로운 개념의 ADEPT(Anaerobic Digestion Elutriated Phased Treatment) 공정을 주정폐수에 적용하여 처리 가능성을 평가하였다. CSTR과 ADEPT의 성능 비교 결과 ADEPT공정에서 gas 발생량은 약 2배였으며, 유기물 제거 효율과 고형물 제거 효율 역시 더 높은 효율을 보여주었다. 또한 ADPET는 비교적 짧은 HRT에서도 휘발성 지방산 생성으로 인한 pH 저하의 영향을 받지 않았으며, 안정적으로 pH를 유지하였다. ADEPT의 recycle ratio를 6Qin과 2Qin으로 변화를 주어 운전 시 6Qin의 운전 기간 동안 높은 처리 효율을 보여주었다. 따라서 ADEPT는 짧은 HRT로 인한 경제성 향상과 메탄 발생을 이용한 에너지 회수, 또한 산 생성조에서 생성되는 유기산을 최대로 생산, BNR 공정의 유기 탄소원으로 활용 가치가 있다고 판단된다.