• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.434-437
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• 2000

Streptomyces setonii(ATCC 39116) is a thermophilic gram-positive soil bacteria which undergoes an ortho-cleavage pathway in the presence of phenol or benzoate as a sole carbon and energy source. The specific activities of catechol-1,2-dioxygenase in S. setonii, a key enzyme in ortho-cleavage pathway, were induced by various aromatic compounds such as benzoate, phenol, m-hy-benzoate, p-hy-benzoate, catechol, o-cresol, m-cresol, p-cresol, benzene, toluene, ethyl-benzene, 2-chloro-phenol, and 4-chloro-phenol, among which the phenol showed the highest inducibility in the presence of 0.01% glucose. More than 0.1% glucose dramatically reduced the specific activities of catechol-1,2-dioxygenase induced by most of the single aromatic compounds tested.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.424-425
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• 2000

The effects of the presence of commercial non-ionic surfactants on the cell growth and diesel degradation by Pseudomonas sp. OSD were studied. Most surfactants inhibited the diesel biodegradation at high concentration(1000mg/1). However, some surfactants showed no inhibition at lower concentrations. Tween 20, Brij 58, Brij 78 were not inhibitory to the diesel biodegradation even at high concentration. These chosen surfactants has relatively high HLB values. There exists complicated relationship for diesel bioremediation between cell hydrophobicity, surfactant HLB, contaminants, an soil.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.109-112
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• 2000

Long chain fatty acids (LCFA) are potential inhibitors of bacteria involved in anaerobic digestion because of their surface activity. Precipitation of long-chain fatty acids with iron can improve the anaerobic degradation due to their precipitation and reducing surface properties. Degradation of stearic acid was improved in the presence of iron (II). The methane production was increased 1.6 times as compared to control. Iron-containing soil was applied for degradation of vegetable oil as model case. The methane production was increased 1.5 times as compared to control. Yield of methane production was 0.09 and 0.06L/g COD in experiment and control respectively. Optimum COD/Fe ratio was found 20 mg/mg. Iron (II) can be produced in the treatment system from iron (III) hydroxide or iron containing minerals.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.602-605
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• 2001

Low-temperature adaptation and protection for environmental stresses were studied in the gram-negative soil bacterium Bradyrhizobium japonicum 61A101c. B. japonicum was more resistant to alcohol, $H_2O_2$, heat and freezing following a pretreatment at $4^{\circ}C$, resulting in approximately 10 to 1,000 folds increased survival compared to mid-exponential-phase cells grown at an optimal temperature at $28^{\circ}C$. This phenomena relate to the cold shock protein expressed when cells are exposed to a downshift in temperature. To confirm the presence of cold shock protein genes in B. japonicum, a PCR strategy was employed using a degenerate primer set, which successfully amplified a putative csp gene fragment. Sequence analysis of the PCR product(200bp) revealed csp-like sequences that were up to 96% identical to csp gene of S. typhimurium.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.374-377
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• 2001

답토에서 분리한 균주는 Candida sp. HY200이라 임시 명명하였고, Candida tropocalis 보다 짧은 시간에 xylose를 소모하고, 당내성이 우수하며, flocculation의 특성을 갖고 있다. 260 g/L의 고농도 xylose 배지에서 xylitol 발효는 수율 79%, 생산성 2.14 g/L ${\cdot}$ h의 결과를 얻었다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.578-581
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• 2001

A treatability study was conducted using a hydrocarbon-contaminated soil for the oPtimization of bioremediation strategy best fit to a given set of contamination. The applicability of nutrients, biosurfactant, and oil-degrading microorganisms were examined by monitoring $CO_2$ evolution and oil degradation The addition of inorganic nutrients in the form of slow released fertilizer accelerated the initial rate of $CO_2$ evolution by a factor of 3. The application of oil-degrading microorganisms did not significantly increased $CO_2$ evolution or biodegradation efficiency. Application of a commercial biosurfactant was most effect in terms of the total $CO_2$ evolution and the oil degradation rate. The results indicate that $CO_2$ evolution measurement was found to be a simple and reliable countermeasure of crude oil hydrocarbon mineralization for the rapid determination of the best-fit bioremediation strategy.

• KSBB Journal
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• 제13권5호
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• pp.497-501
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• 1998

A fungus with high phosphate solubilizing activites was isolated from soil using potato dextrose agar-calcium phosphate medium and identified to Penicillium sp. PS-113, based on the morphological characteristics of conidiophore and conidia; flask shape of phialide, simple branching type of conidiophore, and columnar shape of conidial head, in malt extract agar and potato dextrose agar media. The optimum temperature ad initial pH to solubilize rock phosphate in potato dextrose broth-rock phosphate medium were 30$^{\circ}C$ and pH 8.0, respectively. In these conditions phosphate solubilizing activities of Penicillium sp. PS-113 against four types of insoluble phosphate like tricalcium-phosphate, aluminium phosphate, hydroxyapatite and rock phosphate were quantitatively determined. As results, this fungus highly produced free phosphates to the culture broth with the concentrations of 1,283 ppm against tricalcium-phosphate, 585 ppm against rock phosphate, 528 ppm against aluminium phosphate, and 242 ppm against hydroxyapatite, respectively.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.317-321
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• 2005

L- arabinose residues are widely distributed in plant cell walls, where they are present in polymers such as arabinans, arabinoxylans, arabinogalactans and arabinogalactan proteins. L-arabinose suppress intestinal sucrase and decrease the adsorption of sugar in the small intestine, consequently, weight loss and fatness prevent. Now, xylose be used replacement sugar and arabinose be utilized fatness prevent of our time. Various Agricultural surplus like com fiber, contain $20\;{\sim}\;40%$ of hemicellulose. Corn fiber from Agricultural Renewable Biomass was chosen the best suitable material for arabinose production. In this work, we searched about for L-arabinose gene in compost, metagenome pool and indonesian soil. So, the B1029 TS2-8 of L-arabinase gene in compost was selected by YNB media(5% yeast nitrogen base, 5% arabinogalactan). After enzyme reaction with corn fiver, B1029 TS2-8 produced 2.15 g/L of L-arabonose.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.82-85
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• 2005

Doxorubicin is a highly-valuable anthracycline-family polyketide drug with a very potent anticancer activity, typically produced by a Gram-positive soil bacterium called Streptomyces peucetius. Thanks to the recent development of Streptomyces genomics-based technologies, the random mutagenesis approach for Streptomyces strain improvement has been switched toward the genomics-based technologies including the application of DNA microarray systems. In order to identify and characterize the genomics-driven potential target genes critical for doxorubincin overproduction, three different types of doxorubicin overproducing strains, a dnrI(doxorubicin-specific positive regulatory gene)-overexpressor, a doxA (gene involved in the conversion from daunorubicin to doxorubicin)-overexpressor, and a recursively-mutated industrial strain, were generated and examined their genomic transcription profiles using Streptomyces DNA microarray systems. The DNA microarray results revealed several potential target genes in S. peucetius genome, whose expressions were significantly either up- or down-regulated comparing with the wild-type strain. A systematic understanding of doxorubicin overproduction at the genomic level presented in this research should lead us a rational design of molecular genetic strain improvement strategy.

• KSBB Journal
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• 제14권2호
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• pp.198-204
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• 1999

Asymbiotic bacterium with highly effective toxins was isolated from entomopathogenic nematode Steinernema glaseri which has been widely used against various soil-inhabiting pests. The symbiont of S. glaseri was identified as Xenorhabdus nematophilus sp. by using several biochemical and physiological tests. When this strain was released into the hemolymph of insect larva, it produced highly toxic substances and killed the larva within 2 days. Two colony forms that differed n some biochemical characteristics were observed when cultures in vitro. Phase l colonies were mucid and difficult to be dispersed in liquid. Phase II was not mucoid and was easily dispersed in liquid. It did not adsorb neutral red or bromothymol blue. Rod-shaped cell size was highly variable between two phases, ranging 2-10 ${\mu}{\textrm}{m}$. It was also found that only infective-stage nematodes can carry only primary-phase Xenorhabdus in their intestine.