• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.460-465
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• 2003

A bacterium, named as strain KL34, producing extracellular pectinase was isolated from soil. The mophological cheracteristics of the isolated bacterium were gram-negative, rod-shaped and endospore unformed. Production of pectinase of strain KL34 was induced only by polygalacturonic acid added to the culture media as a sole carbon source. Pectinase activity of KL34 reached a maximum value in the culture conditions of pH 8.5 at $25^{\circ}C$. Optimal medium for pectinase production was determined to the composition of 2% polygalacturonic acid, 0.25% yeast extract, 0.02% $K_2HPO_4$, 0.02% $CaCl_2$, and 0.05% KCl per liter. The pectinase activity in the culture supernatant reached the highest amount of 54 U/ml after 3 days cultivation in the optimal media.

• The Korean Journal of Mycology
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• v.17 no.1
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• pp.21-26
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• 1989

Saprelegnia sp. was isolated from water sample of Illgam lake in Kon-Kuk university and physiological and reproductive characteristics of this isolate were studied. The isolate grew at a broad range of temperature of $25^{\circ}C\;to\;30^{\circ}C$ and of pH 5 to 6. The maximum growth was attained at the concentrations of 5 mM to 10 mM of phosphate and of 14 g/l of vitamin-free casamino acid. Size of asexual reproductive propagule, zoospore, was $10.3{\mu}$ in diameter and cyst, $11.6{\mu}$. Diameter of oogonium was $47-85{\mu}$ and oospores, $21-31{\mu}$.

• The Korean Journal of Mycology
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• v.11 no.1
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• pp.15-21
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• 1983

Exodextranase from Aspergillus ustus was purified by chromatography and characterized by various conditions. The optimal pH of the purified dextranase was 6.5 and this enzyme was maximally activated at $40^{\circ}C$. The enzyme was stable at the temperature below $50^{\circ}C$. The enzyme was markedly inactivated by $Hg^{2+},\;Cu^{2+},\;KCN\;and\;Co^{2+},\;but\;Ba^{2+},\;Fe^{2+},$ cysteine, EDTA, and ascorbic acid enhanced the activity of the enzyme. The main products from the hydrolysis of dextran incubated with the dextranase were glucose, isomaltotriose and oligosaccharide. When dextran was incubated with the mixture of pullulanase and ${\alpha}-amylase$, it was hydrolyzed into glucose, isomaltose and oligosaccharide. Polysaccharides in the decade teeth powder were hydrolyzed by the dextranase into glucose, isomaltotriose and oligosaccharides. In the hydrolysis of the teeth powder with the mixture of dextranase, pullulanase and ${\alpha}-amylase$, were proved to be similar to the dextran hydrolysates.

• Korean Journal of Food Science and Technology
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• v.17 no.4
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• pp.258-264
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• 1985

The energy for cooking starch prior to saccharification could be saved by fermenting raw starch into ethanol using Aspergillus niger koji of wheat bran. Optimum cultivation time to produce glucoamylase was 4 days in wheat bran medium. The rate of saccharification from uncooked corn starch were optimum at pH 3.3 and 40-$50^{\circ}C$. Corn and sweet potato starch were saccharified more efficiently by wheat bran koji than other tested starch sources. 5 days of fermentation were required for optimum yield of ethanol using a mixture of AspergiUus niger koji and dried yeast. Final ethanol yields from raw corn, sweet potato, and rice starch with agitation at the rate of 100 rpm were about 95% at $30^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.5
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• pp.779-784
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• 1995

The effective production of 5'-GMP(5'-Guanylic acid) by immobilized 5'-GMP producing fusant RC102(intergeneric protoplast fusion between Brevibacterium ammoniagenes ATCC21263 and Corynebacterium glutamicum ATCC21171) was investigated. The Fusant RC102 was immobilized by entrapping in -carrageenan, agar, polyacrylamide or Ca-alginate. 3% k-carrageenan was selected as the most suitable matrix. In the production of 5'-GMP using the immobilized whole cells of fusant RC102, the optimum conditions were $32^{\circ}C$, pH 8.0, $30\mu\textrm{g}/L\;of\;Mn^{2+},\;1{\times}10^{-6}%\;of\;Zn^{2+}$. In order to use fermentation medium containing CSL(Corn Steep Liquor) plentiful in $Mn^{2+}$, the optimum conditions of penicillin G, D-cycloserine and POESA(polyoxyethylene stearylamine) for production of 5'-GMP were 0.8unit/ml, 0.8unit/ml, 0.8unit/ml and 5mg/ml, respectively. Cationic surfactant, POESA was effective and superior to the antibiotics, penicillin G or D-cyloserine in 5'-GMP productivity. The condinuous fermentation using immobilized fusant RC102 showed that 5'-GMP productivity was stable for more than 15 days.

• Microbiology and Biotechnology Letters
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• v.42 no.3
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• pp.225-231
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• 2014

In this study about the optimum conditions for the production of laccase, a polyphenol oxidase involved in lignin degradation, from Marasmius scorodonius, a white-rot fungus garlic mushroom, were determined. Amongst the tested media used for the enzyme's production, YM medium (1% dextrose, 0.5% malt extract, 0.3% yeast extract) allowed for the highest activity of the enzyme. Then, to optimize the culture conditions for laccase activity, the influence of various carbon and nitrogen sources was investigated in YM medium. Among various carbon and nitrogen sources, 1% galactose and 0.4% yeast extract resulted in the highest production of the enzyme, respectively. Enzyme production attained its highest level after cultivation for 15 days at $25^{\circ}C$. Zymogram analysis of the culture supernatant showed two isoenzymatic bands with molecular masses of 60-70 kDa. The optimum pH and temperature for enzyme activity were 3.4 and $75^{\circ}C$, respectively.

• Applied Biological Chemistry
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• v.48 no.3
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• pp.207-211
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• 2005

The metabolites released from cultures of rhizosphere bacteria can inhibit plant growth. Bacillus subtilis IJ-31 inhibited plant growth by the production of hydrocinnamic acid (HCA). The production of HCA by plant-growth inhibiting rhizobacterium B. subtilis IJ-31 was optimized. $90.5\;{\mu}g/ml$ of HCA was obtained under the condition of 1% rice bran as carbon source, 0.5% tryptone as nitrogen source, 0.1% $ZnCl_2$ as metal source at $37^{\circ}C$ for 60 h (pH 7.0). The optimal condition for the HCA production by B. subtilis IJ-31 in the jar fermenter was established using response surface methodology (RSM) of statistical analysis system(SAS) program. The production of HCA by B. subtilis IJ-31 in the jar fermenter culture reached $102.99\;{\mu}g/ml$ when 2.24% soil extracts was added and agitation speed was 290 rpm under the same condition. And the experimental value of HCA production is $102.5\;{\mu}g/ml$ in the same culture condition. The production of HCA by B. subtilis IJ-31 is higher as 12% than that from the flask culture.

• KSBB Journal
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• v.10 no.3
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• pp.283-291
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• 1995

The characteristics of aminopeptidase M(ApM) immobilized covalently on Cellufine Formyl and the continuous production of authentic human growth hormone(hGH) from methionyl human growth hormono(met-hGH) using the column reactor packed with immobilized ApM were investigated. Immobilized ApM with the proportion of 2.3mg ApM per 1g Cellufine Formyl gel had the highest met-hGH conversion activity. The optimum pH(7.0) and temperature($55^{\circ}C$) showed no appreciable difference between free and immobilized enzymes and the optimum temperature in continuous operation of the column reactor was also found to be $55^{\circ}C$. Under the conditions at which met-hGH was converted completely to hGH, the yield and productivity were about 77% and 0.8mg hGH/ml$.$h, respectively. In two column reactors of different sizes, met-hGH was converted to hGH with the same conversion rates and hGH yields at the same space velocities. The half-life of the reactor systems at $45^{\circ}C$ and $55^{\circ}C$ were projected from the continuous operations for 90 days to be 225 days and 81 days, respectively.

• Journal of Life Science
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• v.20 no.10
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• pp.1433-1442
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• 2010

Parameters related to dissolved oxygen for the production of pullulan by Aureobasidium pullulans HP-2001 were optimized in 7 l and 100 l bioreactors. The optimal concentrations of glucose and yeast extract for the production of pullulan were 50.0 and 2.5 g/l, respectively, and its conversion rate from glucose was 37% at a flask scale. The optimal initial pH of the medium and temperature for cell growth were 7.5 and $30^{\circ}C$, whereas those for the production of pullulan were 6.0 and $25^{\circ}C$. The optimal agitation speed and aeration rate for cell growth were 600 rpm and 2.0 vvm in a 7 l bioreactor, whereas those for the production of pullulan were 500 rpm and 1.0 vvm. The production of pullulan with an optimized agitation speed of 500 rpm and aeration rate of 1.0 vvm was 18.13 g/l in a 7 l bioreactor. Maximal cell growth occurred without inner pressure, whereas the optimal inner pressure for the production of pullulan was 0.4 kgf/$cm^2$ in a 100 l bioreactor. The production of pullulan under optimized conditions in this study was 22.89 g/l in a 100 l bioreactor, which was 1.38 times higher than that without inner pressure.

• Korean Journal of Food Science and Technology
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• v.16 no.4
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• pp.392-397
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• 1984

These experiments were conducted to investigate general enzymatic characteristics of two forms(glucoamylase I and glucoamylase II) of the purified glucoamylase produced by Rhizopus oryzae. Molecular weights of glucoamylase I and glucoamylase II estimated by Sephadex G-100gel filtration, were approximately 101,000 and 115,000, respectively, and those estimated by SDS-polyacrylamide gel electrophoresis being 120,000 and 127,000, respectively. Isoelectric points of the above enzyme were pH 7.25 and pH 7.75. The optimum temperature was $50^{\circ}C$ and the enzyme was stable below $45^{\circ}C$. Optimum pH of both glucoamylase I and glucoamylase II was about pH 5.0. The stable pH range of them were pH 3.5-8.0 and 4.5-8.0, respectively. Michaelis constants of glucoamylase I and glucoamylase II toward souluble starch were 4.545 mg/ml and 5.560 mg/ml, respectively. $Hg^{++}$, $Pb^{++}$, p-CMB and IAA were inhibitors of glucoamylase I and $Hg^{++}$, $Mn^{++}$, p-CMB and IAA were inhibitors of glucoamylase II.