• Biotechnology and Bioprocess Engineering:BBE
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• 제7권4호
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• pp.201-205
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• 2002

The growth conditions of Pantoea aggicmerans, a phosphate solubilizing organism, were studied In our laboratory to determine the optimal conditions. Pantoea aggionerans showed the highest growth rate at 30$\^{C}$, pH 7.0 and 2 vvm, after 50 h cultivation. A certain relationship between pH and phosphate concentration was evident when the glucose concentration in the me dium was changed. Increasing glucose concentration increased the pH buffer action of the broth. At glucose concentrations higher than the optimum concentration of 0.2 M, the cell growth was retarded. P. agglomerans consumed glucose as a substrate to produce organic acids which caused the pH decrease in the culture medium. The phosphate concentration in the medium was increased by the presence of the organic acids, which solubilized insoluble phosphates such as hydroxyapa-tite.

• Bulletin of the Korean Chemical Society
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• 제33권8호
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• pp.2651-2656
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• 2012

Sulfonated cellulose tris(3,5-dimethylphenylcarbamate) (SCDMPC)-coated zirconia monolith (ZM) was used as the chiral stationary phase in capillary electrochromatography for separation of enantiomers of ten chiral compounds in acetonitrile (ACN)-phosphate buffer mixtures as the eluent. Influences of the ACN content, buffer concentration and pH on chiral separation have been investigated. Separation data on SCDMPC-ZM have been compared with those on CDMPC-ZM. Resolution factors were better on SCDMPC-ZM than CDMPC-ZM while retention factors were in general shorter on the former than the latter. Best chiral resolutions on SCDMPC-ZM were obtained with the eluent of 50% ACN containing 50 mM phosphate at pH around 4.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.671-674
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• 2001

정제, 농축된 free CGTase 는 pH 6.0 - 7.0의 범위에서 안정하였으며, $70^{\circ}C$정도의 고온에서도 안정한 특성을 가지고 있었으며, CGTase의 고정화를 위한 방법으로서 CNBr-activated sepharose 4B에 의한 고정화가 가장 높은 효율올 나타내는 것으로 결정되었다. 고정화의 최적조건은 $30^{\circ}C$, 60rpm, pH 6.0의 phosphate buffer 하에서 9 시간 동안 고정화하는 것이었고, CNBr-activated sepharose 4B를 이용한 고정화의 경우 실험에 사용된 다른 모든 이온교환 수지에서 얻어진 효율에 비해 월등한 효과를 보였다.

• 한국미생물·생명공학회지
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• 제21권2호
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• pp.176-180
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• 1993

Survival and heat resistance of Listeria monocytogenes Scott A in various nutritional environments and cell type on stainless steel were determined. Viable cell of L. monocytogenes Scott A was most rapidly decreased in phosphate buffer among various media such as NSM (30 g TSB/1 l D.W.), LNM (2 g TSB/1 l D.W.) and phosphate buffer (pH=7) during incubation at 21 and 35C but survived for 15 days at 21C. Vegetative and starved L. monocytogenes Scott A were survived after heat treatment for 5 min at 65C while not detected at 72C.

• Journal of Microbiology and Biotechnology
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• 제5권3호
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• pp.149-153
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• 1995

A simple and low-cost medium was developed for the growth of Bifidobacterium longum KFRI 977. Of three bifidobacterial strains, B. longum KFRI 977 (ATCC 15707) showed the best growth in MRSC broth containing 0.3% oxgall, grew well in partially anaerobic condition, exhibited highest $\beta$-galactosidase activity, and was inhibitory against Clostridium perfringens KFRI 434. Of three developed media, the population of B. longum KFRI 977 was highest (1.9$\times$$10^9$/ml) in ISP based medium. The composition of ISP based medium is ISP (5%), glucose (1%), L-cysteine HCI (0.05%), Trypticase peptone (0.5%), yeast extract (0.5%), $MgSO_4$ (0.05%), Tween-80 (0.1%), and phosphate buffer (pH 7.0). Hydrolysis of ISP by Protease A was unnecessary, and the use of phosphate buffer (pH 7.0) prevented the formation of protein precipitate. Associative culture of B. longum KFRI 977 with Lactobacillus acidophilus KFRI 233 was proven to be deleterous to the growth of B. longum KFRI 977.

• 한국식품영양과학회지
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• 제22권6호
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• pp.797-802
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• 1993

The properties of the alcohol-oxidase from yeasts assimilating of methanol(Hansenula polymorpha CBS 4732, Pichia pastoris CBS 2612 and Candida boidinii CBS 8106) as free(cellules, purified enzymes) and immobilized forms(immobilized cellules, immobilized enzymes) were investigated. Immobilization enhanced the activity and stability of alcohol-oxidase to a certain degree. The optimum temperature of the immobilized alcohol-oxidase was lower than those of the free forms. The pH / activi쇼 profiles of alcohol-oxidase did not change by immobilization, but changed by the microorganisms. When the immobilized cellules were stocked at 4$^{\circ}C$ in 10mM potassium phosphate buffer(pH 7.5 or 8.0), alcohol-oxidase was more stable than those were stocked in potassium phosphate buffer containing 0.65M sucrose. The immobilization modifies the conditions of oxidation on the various substrates. alcohol-oxidase in immobilized forms showed some with higher Km value for methanol than that in free ones.

• 분석과학
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• 제17권6호
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• pp.464-469
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• 2004

순환 전압전류법을 이용하여, 1 mM 인산염 완충용액에서 루테늄-쿠페론 착물의 전기화학적 행동을 살펴보았다. 루테늄 정량의 최적 조건은 1 mM 인산염 완충용액 (pH 6.0), 0.1 mM 쿠페론의 용액에서 주사속도는 100 mV/s 이었다. 이 조건에서 농도 변화에 따른 선형 주사 전압곡선의 환원 봉우리 전류변화를 이용하여 얻은 루테늄의 검출 한계 ($3{\sigma}$)는 $1.2{\times}10^{-7}M$ 이다.

• Archives of Pharmacal Research
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• 제23권3호
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• pp.197-201
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• 2000

In an aqueous piperacillin sodium solution, a well-defined single wave or single peak was observed by direct current(DC) polarography or differential pulse polarography(DPP). The peak potential change per pH unit was -54 mV in the phosphate buffer at $18^{\circ}C$, which indicated that protons were involved in the electrochemical reduction of the 2,3-dioxopiperazine moiety of piperacillin sodium with a $H^{+}e^{-}$ ratio of one. Using a phosphate buffer of pH 4.3, the $1.0{times}10^{-7}$ M piperacillin sodium single peak could be determined by DPP with relative standard deviation of 1.6 %(n=3). Piperacillin sodium could be analyzed with-out interference from penicillin G-potassium, which enabled the employment of DPP as a fast and simple technique for monitoring the synthetic process of the antibiotic.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.142.3-143
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• 2003

Time-dependent PPO activity was determined at $4^\times$C and $30^\times$C. The result of activity determination, PPO extracted by phosphate buffer containing triton x-1l4(tPPO) was more stable than PPO by phosphate buffer(bPPO). The result of electrophoresis, at first a band was appeared at 48kd. After 1-3days a partial degrade band was appeared in bPPO and three partial degrade bands in tPPO. No activity band was appeared in PPOs at $30^\times$C and bPPO at $4^\times$C after 4 days. (omitted)

• Bulletin of the Korean Chemical Society
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• 제33권4호
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• pp.1290-1296
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• 2012

Fenton reaction and iron autoxidation have been debated for the major process in ROS mediated DNA cleavage. We compared both processes on iron oxidation, DNA cleavage, and cyclic voltammetric experiment at different pHs. Both oxidation reactions were preferred at basic pH condition, unlike DNA cleavage. This indicates that iron oxidation and the following steps probably occur separately. The ROS generated from autoxidation seems to be superoxide radical since sod exerted the best inhibition on DNA cleavage when $H_2O_2$ was absent. In comparison of cyclic voltammograms of $Fe^{2+}$ in NaCl solution and phosphate buffer, DNA addition to phosphate buffer induced significant change in the redox cycle of iron, indicating that iron may bind DNA as a complex with phosphate. Different pulse voltammogram in the presence of ctDNA suggest that iron ions are recyclable at acidic pH, whereas they may form an electrically stable complex with DNA at high pH condition.