• Journal of Microbiology and Biotechnology
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• 제9권4호
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• pp.443-449
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• 1999

Bacillus subtilis BK-17 which produces a novel protease with fibrinolytic activity was isolated from soybean paste. Bioreactor production of the enzyme was studied in order to optimize fermentation conditions such as medium concentration, pH, agitation speed, and temperature. Under most cultural conditions, enzyme production initially began when the cell growth stopped. The onset of the enzyme production was indicated by rapid increase in both dissolved oxygen (DO) and pH. Two- to three-times more concentrated medium than the flask optimum medium yielded higher enzyme production in the bioreactor fermentation. When the medium pH was controlled constant, pH 6.5 exhibited the highest activity in the range of 6.0 to 7.5, but the activity was similar to the case when the pH was initially adjusted to 7.5 and subsequently maintained within a relatively wide range of 6.4 to 7.8. Agitation speed did not affect the enzyme production with an exception of DO reaching zero. Fermentation time was reduced when temperature increased within the range of $25^{\circ}C$ to$37^{\circ}C$. However, the highest activity, along with the slow decrease of the enzymatic activity after reaching the maximum value, was observed at $25^{\circ}C$. By shifting the temperature from $37^{\circ}C$ to $25^{\circ}C$immediately after DO reached the minimum level, the high enzyme production of 1,100 U/ml along with the short fermentation period of 13 h could be obtained.

• Journal of Microbiology and Biotechnology
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• 제4권2호
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• pp.134-140
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• 1994

An antagonistic bacterium Pseudomonas stutzeri YPL-1 liberated extracellular chitinase and $\beta$-1,3-glucanase which are key enzymes in the decomposition of fungal hyphal walls. The lytic enzymes caused abnormal swelling and retreating at the hyphal tips of plant pathogenic fungus Fusarium solani in a dual culture. Scanning electron microscopy revealed the hyphal degradation of F. solani in the regions interacting with P. stutzeri YPL-1. The production of chitinase and properties of a crude preparation of the enzyme from P. stutzeri YPL-1 were investigated. Peak of the chitinase activity was detected after 4 hr of cultivation. The enzyme had optimum temperature and pH of 50$^{\circ}C$ and pH 5.3, respectively. The enzyme was stable in the pH range of 3.5 to 6.0 up to 50$^{\circ}C$. The enzyme was significantly inhibited by metal compounds such as $HgCl_2$, but was stimulated by $CoCl_2$. P. stutzeri YPL-1 produced high levels of the enzyme after 84 hr of incubation. Among the tested carbon sources, chitin was the most effective for the enzyme production, at the concentration level of 3%. As a source of nitrogen, peptone was the best for the enzyme production, at the concentration level of 4%. The maximum amount of enzyme was produced by cultivating the bacterium at a medium of initial pH 6.8.

• Journal of Applied Biological Chemistry
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• 제49권3호
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• pp.106-109
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• 2006

Improvement of L-asparate ${\beta}-decarboxylase$ production from Pseudomonas dacunhae ATCC 21192 was attempted by optimizing fermentation conditions. Optimum carbon and nitrogen sources for cell growth and enzyme production were determined. L-Glutamate (2%) was the most suitable carbon source, and D-glucose, D-glycerol and fumarate repressed enzyme production. Yeast extract (2%) was the most effective as nitrogen source. A slight change of pH to 6.5 from medium pH resulted in a meaningful increase in the production of enzyme. The production of the enzyme was highly improved by using 2% yeast extract and 2% L-glutamate in culture media. Maximum L-asparate ${\beta}-decarboxylase$ activity reached up to over 24 U/mL-broth by 15 h flask fermentation.

• 한국미생물·생명공학회지
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• 제17권5호
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• pp.519-523
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• 1989

Aspergillus sp.로부터 glucoamylase를 생성키 위한 조건을 검토하였다. 곰팡이는 탄소원으로 soluble starch, 질소원으로 yeast extract를 사용했을 때 최대 효소생성을 얻을 수 있었다. 그리고, 탄소원 및 질소원의 농도에 따른 효소생성은 soluble starch를 5%, yeast extract를 1% 수준으로 사용했을 때 효소생성은 극대화하였다. 또한 배지의 초기 pH를 6.0, 그리고 배양온도를 28$^{\circ}C$로 유지했을 때 효소생성이 높았다. 고체배지를 사용했을 때에는, 밀기울 배지가 glucoamylase 생성을 위해서 가장 효과가 좋았다.

• Asian-Australasian Journal of Animal Sciences
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• 제2권3호
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• pp.338-339
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• 1989

• 환경위생공학
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• 제5권2호
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• pp.103-110
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• 1990

For production of thermophilic and alkaline protease, Bacillus sp. strain AP-5 was isolated from a compost. The production of the protease was reached at maximum for 4 days at $55^{\circ}$ in standing culture. Chitin and Cellulose as carbon source, and Skim Milk as nitrogen source were favorable for the production of the enzyme. Optimal temperature and optimal pH of the enzyme was $55^{\circ}$ and 11, respectively. Metal ion didn't effect on the enzyme activity, the protease was very stable at heat treatment of 30 min at $55^{\circ}$.

• 한국미생물·생명공학회지
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• 제25권2호
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• pp.151-158
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• 1997

For the production of potent chitinolytic enzyme from bacteria, screening was carried out. Of 100 samples from soil, fresh water and sea water collected from the Kyung-gi area, 7 strains of chitinolytic bacteria were isolated. Among them, Aeromonas hydrophila 5-3K showed the highest chitinolytic activity. Culture conditions of Aeromonas hydrophila for the production of chitinolytic enzyme were inverstigated and lytic enzyme was fractionated by the use of ammonium sulfate and Sephadex G-100. Maximum production of chitinolytic enzyme was obtained at pH 7.0 and 30$\circ$C with chitin concentration between 0.2% and 1.0%. Conditions for the enzyme production were optimized including fermentor cultivation. The chitinolytic system of Aeromonas hydrophila 5-3K was composed of two enzymes, chitinase and chitobiase.

• Asian-Australasian Journal of Animal Sciences
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• 제16권5호
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• pp.677-684
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• 2003

Twenty eight multiparous lactating cows were utilized in an experiment to evaluate the response to an exogenous fibrolytic enzyme on their lactational performance during early lactation period (in terms of milk production, milk composition, feed intake, milking efficiency, body weight change) and the exact time of this response. Cows were randomized into two groups (14 each) with similar parities and were fed a concentrate ration of barley, ground corn, soybean meal, and wheat bran and roughage ration of alfalfa hay. One of the two groups was supplemented with the fibrolytic enzyme immediately after parturition up to 100 post partum. The experiment was of two phases with 50 days each. The enzyme, which has a cellulase/hemicellulase activity (derived from Trichoderma group), was added to the concentrate part of the ration in a dry powder form. Milk production, 3.5% fat corrected milk, energy corrected milk were higher (p<0.05) for cows fed treated diet. At the same time, No differences were observed in percentages of milk components, feed intake, body weight, body weight change, or rectal temperature for the whole experimental period or during any of the two phases. Efficiency of milk production was higher (p<0.05) for treatment group cows than for that of the control ones. However, efficiency was better during the second phase than during the first phase. Feeding enzyme treated diets to dairy cows improved lactational performance during early 100 day of the lactation period. However, the first 50 days of lactation looked to be the critical.

• Mycobiology
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• 제33권2호
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• pp.84-89
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• 2005

Five types of agricultural wastes were used for the production of xylanolytic enzyme by Aspergillus flavus K-03. All wastes materials supported high levels of xylanase and ${\beta}-xylosidase$ production. A high level of proteolytic activity was observed in barley and rice bran cultures, while only a weak proteolytic activity was detected in corn cob, barley and rice straw cultures. Maximum production of xylanase was achieved in basal liquid medium containing rice barn as carbon source for 5 days of culture at pH 6.5 and $25^{\circ}C$. The xylanolytic enzyme of A. flavus K-03 showed low thermostability. The times required for 50% reduction of the initial enzyme activity were 90 min at $40^{\circ}C$, 13 min at $50^{\circ}C$, and 3 min at $60^{\circ}C$. Xylanolytic activity showed the highest level at pH $5.5{\sim}10.5$ and more than 70% of the original activity was retained at pH 6.5 and 7.0. The higher stability of xylanolytic enzymes in the broad range of alkaline pH is useful for utilization of the enzymes in industrial process requiring in alkaline conditions. Moreover, the highest production of xylanolytic enzyme was obtained when 0.5% of rice bran was supplied in basal liquid medium. SDS-PAGE analysis revealed a single xylanase band of approximately 28.5 kDa from the culture filtrates.

• 한국식품영양학회지
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• 제2권2호
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• pp.8-13
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• 1989

A strain of Saccharomyces cerevisiae BY-366 was found to produce a strong sucrose-hydrolyzing enzyme Using this strain, the optimal culture conditions for the production of invertase were investigated. The results are as follows : 1. For enzyme production, optimal temperature, initial pH and critical concentrations of sucrose and raffinose were 3$0^{\circ}C$, 5.0 and 3.0%, respectively. 2. Enzyme production was reached maximum by organic nitrogen source, 0.3% yeast extract plus 0.5% bactopeptone. 3. It was appeared the presence of 0.1 M Mn2+ and Fe2+ ion was essential factors, on the other hand, 0.1 M Ag+ and Hg2+ ion almost block in yeast growth and enzyme production. 4. Invertase productivity was reached maximum within 3 days on stationary culture with medium-composed of sucrose 3%, bactopeptone 0.5%, yeast extract 0.3%, KEHPO. 0,1%, MgSO4.7H2O 0.05%.