• Journal of Life Science
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• v.12 no.1
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• pp.77-86
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• 2002

Chitin, a $\beta$-1,4 polymer of N-acetyl-D-glucosamine, is one of the most abundant organic compounds in nature. Chitinase (EC 3.2.1.14) is an enzyme that degrades chitin to chito-oligosaccharides, diacetyl rhitobiose and N-acetyl-D-glucosamine. An extracellular chitinase-producing bacterial strain was isolated from soil and named to as Bacillus subtilis JK-56. Optimum culture condition of B. subtilis JK-56 for the production of chitinase was 1% chitin, 0.5% polypepton, 0.1% KCl, 0.05% MnS $O_4$.4$H_2O$, 37$^{\circ}C$, initial pH 7.0 and 40 hour culture time. When B. subtilis JK-56 was grown in the optimum medium, one major active band and two minor active bands were detected by native-PAGE and active staining of the gel. Among them, the major band was purified from the culture supernatant by 70% ammonium sulfate precipitation and native-PAGE with BIO-RAD Model 491 Prep-Cell and named as Chi-56A. Its molecular weight was estimated to be 53kDa monomer and the isoelectric point (pI) was pH 4.3. The pH and temperature for the optimum activity of Chi-56A were pH 6.0 and $65^{\circ}C$, respectively. Chi-56A was stable up to $65^{\circ}C$ and in alkaline region. Its $K_{m}$ value for colloidal chitin was 17.33g/L. HPLC analysis of the reaction products confirmed that Chi-56A was an exo type chitinase.e.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.6
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• pp.1020-1026
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• 1994

Pseudomonas plycolor was used to investigated the optimal culture condition to examine the various properties of superoxide dismutase (SOD). this SOD was inhibited by $H_2O_2$, azide ion, but not by cyanide ion. This result indicates that the enzyme might be a Fe-SOD. The composition of optimal culture medium for the enzyme production was 3% of glycerin, 1% of polypeptone, 0.5% of meat extract, 0.2% of KCI and the initial ph was 9.0 . The cultivation for the enzyme production was carried out in 500ml shaking flask containing 100ml of the optimal medium at $30^{\circ}C$ on a reciprocal shaker. The enzyme production reached maximum at 15hrs of cultivation and then declined sharply afterward.

• Applied Biological Chemistry
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• v.22 no.3
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• pp.150-159
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• 1979

Physiological characteristics of the acetic acid bacteria isolated from the clover flower vinegar were studied and the results were summarized as follows. 1. The strains No. 1, 3, 5 were employed. By their biochemical properties observed, they seemed to belong to Acetobacter aceti. Particluarly, the strain No. 3 had the highest productivity of acetic acid. 2, When the acetic acid bacteria preincubated in $7^{\circ}Bx$ Koji extract was inoculated to $3^{\circ}Bx$ Koji extract added 0.15% yeast extract the productivity and peroxidation of acetic acid increased considerably. 3. $3^{\circ}Bx$ Koji extract added 0.005 to 0.01% of $MgSO_4{\cdot}7H_2O$ was good in the maintenance of high concentration of acetic acid. 4. Initial optimum pH of media was 6.0. 5. 2 to 4% of ethanol concentration brought a good result of the productivity and peroxidation of acetic acid in short terms.

• KSBB Journal
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• v.11 no.6
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• pp.654-662
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• 1996

Bacterial strains which degrade crude oil were isolated by liquid culture from oil-spilled soil, and four isolates were selected among them. The strain Hl7-1 was finally selected after testing emulsifying activity and oil conversion rate. The strain Hl7-1 was identified as a Nocardia sp. based on the test for morphological, biochemical and physiological characteristics. It appears to be highly specialized for growth on crude oil in minimal salts medium since it showed preference for oil or degradation products as substrates for growth. It was found that it could grow on at least fifteen different hydrocarbons. The optimum cultural and environmental conditions were seeked. Cell growth and emulsification activity as a function of time were also determined. Crude oil degradation and the reduction of product peak was identified by the analysis of remnant oil by gas chromatography after 3 days of cultivation. Approximately 83% of oil were converted into a form no longer extractable by organic solvents.

• Journal of Life Science
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• v.7 no.1
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• pp.30-38
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• 1997

For screening thermostable $\alpha$-amylase from thermophiles, various samples from extreme environments such as hot spring and sewage near them, and compoat, wereexamined microbial growth in enrichment culture medium at 55$\circ$C on the assumption that enzymes from thermophiles are inevitable thermostable. One strain showing higher $\alpha$-amylase activity was pure cultured and designated as Bacillus sp. TR-25 from the results of morphological, cultural and physiological characteristics. The most important carbon sourses for the enzyme production were soluble starch, dextrin, potato starch and corn starch. Glucose and fructose had a catabolite repression on the enzyme production. The good nitrogen sources for the enzyme production were yeat extract, nutrient broth, tryptone, corn steep liquor and ammonium sulfate. The enzyme production was accelerated by addition of CaCl$_{2}$. $\cdot $ H$_{2}$O. The optimal medium composition for the enzyme production was soluble starch 2.0%, yeast extract 0.55, CaCl$_{2}$ $\cdot $ 2H$_{2}$O 0.015, Tween 80 0.001%, pH8.0, respectively. In jar fermenter culture, this strain shows a rapid growth and required cheaper carbon and nitrogen source. These properties are very useful to fermentation industry. The $\alpha$-amylase of this strain demonstrated a maximum activity at 80$\circ$C, pH 5.0, respectively. And calcium ion did not improve thermostability of the enzyme. At 10$0^{\circ}C$, this enzyme has 235 of relative activity. Transformation was carried out by thermophilic Bacillus sp. TR-25 genomic DNA. As a result, the transformant has increased thermostable $\alpha$-amylase activity.

• The Korean Journal of Mycology
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• v.36 no.1
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• pp.26-30
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• 2008

This study was carried out to develop artificial culture method of Grifola frondosa in polypropylene bag. To find out the favorable substrate formulation of G. frondosa, physicochemical conditions were investigated. The T2 formulation (55 : 25 : 12 : 8) mixing ratio of oak sawdust, oak chip, dried bean-curd refuse and wheat bran showed the shortest time to complete the crop cycle and the highest yield (weight of fresh mushrooms harvested at maturity). Those physicochemical conditions were pH 4.3, 2.4% crude fat contents, 54.1% total carbon, 1.42% total nitrogen, 38.1 C/N ratio, 75.5% porosity and $0.21\;g/cm^3$ bulk density. Among the physicochemical factors, pH, crude fat and total nitrogen may affect mushroom yield. Therefore, development of favorable substrate would be benefit to increase production efficiency of G. frondosa, mushrooms and be commercial potential.

• The Korean Journal of Mycology
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• v.2 no.1
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• pp.25-29
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• 1974

1. Penicillium sp. C 13-13 strain was obtained with the treatment of mutagenic agents(N.T.G.) and by single spore isolation method from the Penicillium sp. C8-14 strain, which was reported in the previous paper. 2. The above strain had a few spores and to obtain seed culture, it was cultured at $30^{\circ}C$ and initial pH $4.5{\sim}5.0$, with air rate 6l/min., and agitation 600 rpm for 48 hours in 10% wheat bran medium in 20l- Jar fermenter. When the broth that had above 70ml of mycelium was inoculated into wheat bran medium and incubated at $29{\sim}33^{\circ}C$ for 72 hrs, the cellulase activity of the koji was higher. 3. Adding calcium chloride and magnecium sulfate to the wheat bran medium to 1.5% and 0.015% respectively, the cellulase activity of the koji was higher than that of the control.

• Journal of Mushroom
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• v.4 no.2
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• pp.62-67
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• 2006

Pholiota nameko is one of the four major profitable mushrooms along with oak mushroom, winter mushroom, and oyster mushroom. It contains abundant proteins, carbohydrates, organic acids and vitamins. Its unique taste and flavor as well as its nutritional features make it widely favoured. Mushroom complete medium was the optimal medium for mycelial growth of Pholiota nameko. The optimal temperature and pH for the mycelial growth were $25^{\circ}C$ and 5.0, respectively. The best carbon sources for mycelial growth were glucose and mannose, and the best nitrogen sources were yeast extract, peptone, asparagine, etc. The 8:2 ratio mix of oak sawdust and wheat bran was the best for the bottle cultivation. The best mushroom was yielded after 30 days incubation. The best yield was produced with 850g of medium weight in a PP bag and bottle.

• The Korean Journal of Mycology
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• v.26 no.1 s.84
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• pp.51-55
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• 1998

After bottle culture of Pleurotus ostreatus, sawdust was taken out from the bottle and accumulated in the middle of March, and then composted. As the result, Y value was decreased rapidly 30 days after composting, and it was decreased slowly after 30 days. It is considered that 118 days is required for composting, however, it is possible to use for casing material after at least 48 days composting. The pH and total nitrogen content of sawdust based on composting period had tendency to increase as composting was processed. Total carbon and C/N rate had tendency to decrease as time went on. Based on the rate of 10, 30 and 50%, each sawdust was added to clay loam used as casing material for culturing A. bisporrus. Among various treatments, the mycelial growth of A. bisporus was more favorable in the treatment of 30% sawdust than in the single treatment of clay loam. Based on the date necessary for primodium formation of A. bisporus, the primodium formation in the treatment of 30% sawdust was reduced to about 5 days as compared with that of any other treatments When 30% sawdust was added to clay loam used as casing material for culturing A. bisporus, the yield of its fruiting body was increased to 28%.

• Journal of Mushroom
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• v.20 no.3
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• pp.183-185
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• 2022

High-income mushroom crops require complex farming. Therefore, we conducted a test to identify the optimum temperature for the production of antler-shaped Ganoderma lucidum using the King Oyster mushroom cultivation facility. T-N showed 0.28% of oak sawdust and 2.2% of nutritional source. The pH of oak sawdust was 6.0, indicating weak acidity, and that of rice steel was 6.6, indicating neutrality in nutrition source. Study on the quality characteristics of mushrooms showed that the number of days at 25℃ were 5~6 and those at 30℃ were 3~5; the representative length at 25℃ was 57.5 mm and that at 30℃ was 92.2 mm; the biological weight at 25 ℃ was 43 g, which was greater than that at 30℃.