• Biotechnology and Bioprocess Engineering:BBE
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• 제7권6호
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• pp.331-334
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• 2002

Culture conductivity and on-line NADH fluorescence were used to measure cellular growth in plant cell suspension cultures of Podophyllum hexandrum. An inverse correlation between dry cell weight and medium conductivity was observed during shake flask cultivation. A linear relationship between dry cell weight and culture NADH fluorescence was obtained during the exponential phase of batch cultivation In a bioreactor under the pH stat (pH 6) conditions. It was observed that conductivity measurement were suitable for biomass characterisation under highly dynamic uncontrolled shake flask cultivation conditions. However, if the acid/alkali feeding is done for pH control the conductivity measurement could not be applied. On the other hand the NADH fluorescence measurement allowed online-in situ biomass monitoring of rather heterogenous plant cell suspension cultures in bioreactor even under the most desirable pH stat conditions.

• Journal of Microbiology
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• 제34권4호
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• pp.316-319
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• 1996

Mycelia of Streptomyces viridochromogenes grown under different pH were analysed for the fatty acid composition. The low relative proportion of 12-methyltetradecanoic acid and the high relative proportion of palmitic acid were characteristic for the young culture under slight acidic pH that caused delay of the aerial mycelium formation. The addition of L-arginine to the culture medium enabled an arginine auxotroph with bald phenotype to have the fatty acid composition similar to that of the wild type and to develop aerial mycelium. The ratio of 12-methyltetradecanoic acid to palmitic acid might be used as a parameter to explain the optimum grwoth in the respect of membrane fluidity.

• 한국식생활문화학회지
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• 제9권4호
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• pp.329-333
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• 1994

발효시간을 $0{\sim}10$시간으로 달리한 증편 반죽에서 발효시간에 따른 이화학적 성질 변화를 검토하였다. 발효경과에 따라 pH는 감소하였으나 적정산도와 젖산은 계속적으로 증가하였다. 발효 중 총당은 계속적으로 감소하였으나 환원당은 발효초기 크게 증가하여 발효 4시간에 건물 기준으로 최대 101 mg/g에까지 도달한 다음 다시 감소하였다.

• 한국미생물·생명공학회지
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• 제25권3호
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• pp.317-321
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• 1997

The effect of ammonium ion concentration on the production of demethyl- chlortetracycline (DMCT) by a DMCT overproducing mutant, Streptomyces aureofaciens 27VR, and the optimal control of pH were studied. The optimum levels of pH control were 6.5-6.6 for 80-120 hr, 6.4- 6.5 for 121-150hr and 6.3-6.4 for 151-190hr. The optimum level of ammonium ion concentration during the pH control was lower than 20 mg%. Under the optimized culture condition, it was possible to produce DMCT with an 18% increase in productivity compared to that of standard culture condition in 190hrs of the fermentor operation.

• Applied Biological Chemistry
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• 제7권
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• pp.67-77
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• 1966

For the production of proteolytic enzyme wilth Aspergillus, the examination is made on the culture-time and koji extracting conditions, during producing koji. 1. The highest activity showed up when the culture-time took 50 hours for Aspergillus sojae and 60 hours for Aspergillus flavus. 2. When the cultured koji was extracted by a buffer solution and water, the former gave the product of higher activity until pH 7 through pH 12, and water until pH 3 through pH 7. 3. In the method of crushing and granule extractions, crushing extraction produced the one of higher activity than granule. 4. The highest activity showed up when Aspergillus sojae took 5 hours (Aspergillus flavus 4 hours) in the time of extracting enzyme solution. 5. The highest activity showed up when both Aspergillu sojae and Aspergillus flavus reacted and indicated $37.60^{\circ}C$ in the reaction temperature and activity.

• Mycobiology
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• 제44권4호
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• pp.260-268
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• 2016

Regulation of alkaline-resistant laccase from Perenniporia tephropora KU-Alk4 was proved to be controlled by several factors. One important factor was the initial pH, which drove the fungus to produce different kinds of ligninolytic enzymes. P. tephropora KU-Alk4 could grow at pH 4.5, 7.0, and 8.0. The fungus produced laccase and MnP at pH 7.0, but only laccase at pH 8.0. The specific activity of laccase in the pH 8.0 culture was higher than that in the pH 7.0 culture. At pH 8.0, glucose was the best carbon source for laccase production but growth was better with lactose. Low concentrations of glucose at 0.1% to 1.0% enhanced laccase production, while concentrations over 1% gave contradictory results. Veratryl alcohol induced the production of laccase. A trace concentration of copper ions was required for laccase production. Biomass increased with an increasing rate of aeration of shaking flasks from 100 to 140 rpm; however, shaking at over 120 rpm decreased laccase quantity. Highest amount of laccase produced by KU-Alk4, 360 U/mL, was at pH 8.0 with 1% glucose and 0.2 mM copper sulfate, unshaken for the first 3 days, followed by addition of 0.85 mM veratryl alcohol and shaking at 120 rpm. The crude enzyme was significantly stable in alkaline pH 8.0~10.0 for 24 hr. After treating the pulp mill effluent with the KU-Alk4 system for 3 days, pH decreased from 9.6 to 6.8, with reduction of color and chemical oxygen demand at 83.2% and 81%, respectively. Laccase was detectable during the biotreatment process.

• Applied Biological Chemistry
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• 제35권6호
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• pp.443-448
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• 1992

현탁배양에 의한 박하 세포의 생장 특성을 살펴보기 위하여 박하 잎으로부터 캘러스를 유기하고 이 캘러스 중 쉽게 퇴화되지 않고 생육 속도가 빠른 우수 세포주를 선발하였으며 선발된 세포주를 현탁 배양하였다. 현탁 배양중 배지의 조성, 식물 생장 호르몬, 배지의 pH가 생육에 미치는 영향을 조사하였다. 배지로서 사용한 Lin-Staba 배지, B5 배지, MS 배지 중 에서는 Lin-Staba 배지에서 세포의 생육이 가장 좋았으며 특히 이 배지에 100 mg/l yeast extract를 첨가했을 때 생육은 크게 저해되었다. 식물 생장 호르몬의 경우는 cytokinin류가 auxin류를 첨가했을 때보다 생장 속도가 더 빨라졌다. 배지의 초기 pH는 생장에 큰 영향을 주지 못하였다.

• 자원리싸이클링
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• 제9권3호
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• pp.46-53
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• 2000

최근 페고무의 증가에 따른 효율적 처리에 대한 관심이 증가하고 있다, 본 실험에서는 페고무를 장미 양약재배 배지의 구성요소로서 폐고의 재활용 방법을 연구하였으며, 배지내의 장미 생육상태, 미량원소, 다량원소, pH 그리고 EC롤 조사하였다. 생육 초기에 장미는 초기위조(morprent wilting)와 같은 증상이 관찰되었으나, 여러 주 후에 회복하였다. 개화 후 배지내의 $Zn^{2+}$의 농도는 페타이어의 함량이 높을수록 증가하였으며, 장미 식재 전 배지내의 pH는 7.17-7.99로 나타났지만, 개화후 배지내의 pH는 5.7-6.35로 식물의 성장에 적합한 상태로 안정화되는 것을 알 수 있었다. 대조구인 암면과 비교하여 폐암만과 EPDM 분말 9:3의 비율로 혼합한 배지를 제외한 모든 배지에서 장미의 초장, 가지수 그리고 생체증 큰 차이를 보이지 않았으며, 유사한 값을 나타내는 것을 알 수 있었다.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2018년도 제58차 하계학술대회논문집 26권2호
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• pp.102-103
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• 2018

최근 국내 게임 시장이 12조원을 육박하고 있는 시장 현황에서 게임 매출 부분에서 게임내 어떤 과금정책을 적용할 것인지가 가장 중요한 요소이다. 시중에 출시된 게임 중에서는 P2W 모델이 접하기 쉬운 모델이긴 하지만 최근에는 B2P 모델을 많이 적용하고 있는 과금정책이다. 본 논문에서는 온라인 게임 내 P2W의 과금 모델과 B2P의 과금 모델의 선호도를 조사한다. 그리고 본 논문에서 새롭게 명명한 T2H 모델의 선호도를 조사하여 어떠한 과금 모델이 게임시장에서 더 유리하고 선호도가 높은 모델인지를 제시한다.

• International Journal of Industrial Entomology and Biomaterials
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• 제34권2호
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• pp.38-44
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• 2017

Mulberry leaves containing 1-deoxynojirimycin (DNJ) have been recognized as a potentially important source for prevent or treat hyperglycemia. However, DNJ content of natural mulberry leaf are as low as 0.1%. Thus, the most effective method for increasing ${\alpha}$-glucosidase inhibitory activity with the DNJ high-production is needed. In this study, we investigated the influence of ${\alpha}$-glucosidase inhibitory activity according to different pH values (6-9) and inoculation amounts (0.1-0.5%) when Bacillus subtilis cultured on mulberry leaf powder media. We confirmed that ${\alpha}$-glucosidase inhibitory activity was difference according to culture conditions of different pH values, inoculation amounts, and fermentation times. The results of mulberry leaf fermentation according to pH values and inoculation amounts were shown that the optimal conditions for ${\alpha}$-glucosidase inhibitory activity were defined as pH 7 and 9, inoculation amount 0.4%, and incubation until 2 to 4 days. These results can be provided a basic data for the optimal culture conditions increasing ${\alpha}$-glucosidase inhibitory activity from mulberry leaf fermentation.