• Journal of Microbiology and Biotechnology
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• 제17권5호
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• pp.712-720
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• 2007

To investigate clonal variations of recombinant Chinese hamster ovary(rCHO) clones in response to culture pH and temperature, serum-free suspension cultures of two antibody-producing CHO clones(clones A and B), which were isolated from the same parental clone by the limiting dilution method, were performed in a bioreactor at pH values in the range of 6.8-7.6, and two different temperatures, $33^{\circ}C\;and\;37^{\circ}C$. In regard to cell growth, clone A and clone B displayed similar responses to temperature, although their degree of response differed. In contrast, clones A and B displayed different responses to temperature in regard to antibody production. In the case of clone A, no significant increase in maximum antibody concentration was achieved by lowering the culture temperature. The maximum antibody concentration obtained at $33^{\circ}C$(pH 7.4) and $37^{\circ}C$(pH 7.0) were $82.0{\pm}2.6$ and $73.2{\pm}4.1{\mu}g/ml$, respectively. On the other hand, in the case of clone B, an approximately 2.5-fold increase in maximum antibody concentration was achieved by lowering the culture temperature. The enhanced maximum antibody concentration of clone B at $33^{\circ}C$($132.6{\pm}14.9{\mu}g/ml$ at pH 7.2) was due to not only enhanced specific antibody productivity but also to prolonged culture longevity. At $33^{\circ}C$, the culture longevity of clone A also improved, but not as much as that of clone B. Taken together, CHO clones derived from the same parental clone displayed quite different responses to culture temperature and pH with regards antibody production, suggesting that environmental parameters such as temperature and pH should be optimized for each CHO clone.

• 동아시아식생활학회지
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• 제9권2호
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• pp.195-199
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• 1999

오징어 내장에서 분리한 protease를 중심합성 계획법을 이용해서 제한조건을 동일하게 하고 pH와 온도를 변수로 protease활성을 모니터링 하였다. 그 결과 protease활성은 41.75$^{\circ}C$, pH 6.02에서 78.65unit로 최고치를 나타내었으며, 이때 $R^2$는 0.8461로서 10% 이내에서 유의성이 인정되었다. 또한 오징어 내장 protease는 50mM의 $Na^{+}$ 첨가에서 활성이 저해되었으나 $Mg_2$$^{+}$에 의해서는 상승효과를 보였으며 km 값은 0.12mM이었다.

• 한국미생물·생명공학회지
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• 제47권4호
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• pp.614-620
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• 2019

Microalgae have been explored as potential host species for biofuel production. Environmental factors affect algal growth and cellular composition. The effects of several key environmental factors, such as temperature, light, and pH of the medium on the growth and biochemical composition of Scenedesmus obliquus were investigated in this study. The highest growth rate of microalgae was observed at an optimal temperature of 25℃, 150 μmol/(m²·s) light intensity, and pH 10.0. The biochemical composition analysis revealed that the carbohydrate content decreased at lower (20℃) or higher temperature (35℃), whereas the protein and lipid contents increase at these temperatures. The fluctuation of light intensity significantly affected the contents of protein, carbohydrate, and lipid. The protein levels varied greatly when the pH of the medium was below 7.0. The carbohydrate and lipid contents significantly increased at pH above 7.0.

• 한국미생물·생명공학회지
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• 제19권4호
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• pp.383-389
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• 1991

저온에서 높은 활성을 나타내는 알칼리성 protease를 생산하기 위하여 여러가지 시료로부터 집적배양에 의해 저온성 세균을 분리하였다. 분리된 세균은 저온.알칼리성 Pseudomonas sp.인 것으로 판명되었으며, 효소생산을 위한 균생육의 최적 pH는 10.0, 온도 $20^{\circ}C$에서 4일간 배양하였을 때였다. 이 효소 활성의 최적 pH 및 온도는 각각 pH 10.5 및 $40^{\circ}C$였으며, pH 및 열안정성은 각각 pH 7.0~13.0, 온도 $50^{\circ}C$이하의 범위에서 비교적 안정하였다.

• 생명과학회지
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• 제12권6호
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• pp.765-768
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• 2002

Rhodotorula sp. CL-82 유래 의 epoxide hydrolase 활성을 이용하여 라세믹 styrene oxide에 대한 입체선택적 가수분해 반응을 실시하였다. Rhodotorula sp. CL-82 생촉매의 입체선택적 가수분해속도를 나타내주는 반응표면 곡선에 대한 분석을 통해 pH, 반응주도, cosolvent 첨가량에 대한 최적조건을 각각 7.6,$33.3^{\circ}C$ , 3%(v/v)으로 결정하였다. 최적반응조건에서 약 4시간 정도의 반응을 통해 ee값이 99% 이상인 광학적으로 순수한 (S)-styrene oxide를 이론 수율대비 40% 수율로 얻을 수 있었다.

• 한국미생물·생명공학회지
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• 제27권3호
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• pp.208-214
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• 1999

The condition for immobilization of the partially purified agarase from Bacillus cereus ASK202 and the properties of the immobilized enzyme have been investigated. Agarase was immobilized on various supports by entrapment method. The enzyme immobilized on Na-alginate bead showed the highest activity among those studied. The optimal reaction conditions of the immobilized agarase were obtained in 3%(w/v) Na-alginate for the matrix, bead diameter of 2.5mm, 1 unit of agarase solution and 1.0%(w/v) calcium chloride solution. The optimum pH and temperature of the immobilized agarase were pH and temperature of the immobilized agarase were pH 7.0 and 4$0^{\circ}C$, respectively. Km and Vmax values were 0.5mg/ml.min, respectively. The immobilized agarase conerted agar to agarobiose, and their total conversion ratio under the optimal condition was 89%.

• 한국어병학회지
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• 제16권2호
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• pp.119-123
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• 2003

We have selected an valuable pmbiotic strain; Lactobacillus sakei BK19 which has wide antagonic spectrum against fish pathogens . Present study investigated cultural characterization of L. sakei BK19 including pH tolerance , susceptibility of antibacterial agents and growth pattern with different environment such as nutritions, temperature and salinity. L. sakei BK19 showed Significantly higher resistance at low pH(around pH 4) environment and relative high antibiotic tolerance . In the study of optimal culture condition, maltose and saccharose provided the optimal nutritional culture condition while lactose and mannitol were unable to supply its carbon source for the fermentation of L. sakei BK19. Moreover. L. sakei BK19 showed good growth at the temperature range of 15 to $45^{o}C$ und the NaCl concentration of 0 to 7%. Hence, this particular probiotic strain may be benificial both in seawater and fresh weter conditions.

• 펄프종이기술
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• 제37권4호통권112호
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• pp.1-7
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• 2005

This study was carried out to investigate the characteristics of extracellular cellulase and xylanase from Fusarium pallidoroseum and Aspergillus niger, such as enzyme activity and stability by various pH, temperature and metal ions, for application into enzymatic deinking system. The optimal temperature and pH for enzyme activity and stability of Fusarium pallidoroseum and Aspergillus niger were $50^{\circ}C$, pH 5.0 and $60^{\circ}C$, pH 9.0, respectively. Certain metal ions, calcium and cobalt, brought to elevate cellulase and xylanase activity from F. pallidoroseum and A. niger. With these results we suggest that enzymatic deinking system should be proceed at $50\~60^{\circ}C$ under their optimal pH condition.

• Environmental Engineering Research
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• 제20권2호
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• pp.121-125
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• 2015

Biohydrogen production from food waste via dark fermentation was conducted by using mixed culture under various environmental conditions (initial pH, initial F/M ratio, initial ferrous iron ($Fe^{2+}$), and temperature condition) in batch reactor. The results revealed that the maximum hydrogen yield of $46.19mL\;H_2/g\;COD_{add}$ was achieved at the optimal conditions (initial pH 8.0, initial F/M ratio 4.0, initial iron concentration 100 mg $FeSO_4/L$ and thermophilic condition ($55{\pm}1^{\circ}C$)). Furthermore, major volatile fatty acid (VFA) productions of butyrate (765.66 mg/L) and acetate (324.69 mg/L) were detected and COD removal efficiency was detected at 66.00%. Therefore, these optimal conditions could be recommended to operate a system.

• Journal of Plant Biology
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• 제8권1_2호
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• pp.19-23
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• 1965

Interaction occuring among the different Ca concentrations, pH and temperatures in the promotive effect of Ca in pollen growth was studied by using pollen from Crinum asiaticum and Cryptostegia grandiflora. Data for pollen tube elongation were found to be more indicative of representing the promotive action of Ca ion in pollen growth than those for pollen germination, and were served to evaluate the experimental results. The pollen growth increased as the concentration of Ca increase. The optimal pH range for pollen growth shifted from the lower pH to the higher as the concentration of Ca increase. The characteristic Ca effect was disappeared, and no pH effect at various ranges was observed when pollen grains were grown at the low temperature(8$^{\circ}C$). The Ca effect became quite pronounced if temperature were raised. The Ca effect became even mroe striking if the condition was in higher pH ranges (weak alkaline). Higher pH ranges were found to be more favorable for the Ca action, whereas higher temperature was required to bring about more pronounced Ca effect. Thus, the longest pollen tube was obtained with the highest pH, temperature adopted for the medium supplemented with Ca in the present experiment, and the shortest tube with the lowest temperature applied at the highest pH. Pectin synthesis in pollen tube was considered as a metabolic process, whereas Ca binding in pectin of the pollen tube wall as non-metabolic in nature. Disappearance of Ca effect at the low temperature was probably brought about by blocking the metabolic synthesis of pectin, and nonmetabolic Ca binding seems to take place more extensively with higher concentrations of Ca and at higher pH levels than the lower.