• Applied Biological Chemistry
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• v.40 no.6
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• pp.484-489
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• 1997

The characteristics of growth and esterase activity of bacterial strains isolated from acid hydrolysed soybean protein were examined. All the isolated strains having decomposition activity of p-hydroxybenzoic acid butyl ester and esterase producing activity were identified as Bacillus sp. by morphological and biochemical methods. The specific growth rates, esterase activities and p-hydroxybenzoic acid butyl ester decomposition activities of isolated strains were $0.844{\sim}1.213\;h^{-1}$, $21{\sim}222\;mU/ml$ and $5.4{\sim}8.1\;mU/ml$, respectively. In the fermentation of Bacillus sp. KB8 strain which had the highest esterase producing activity, growth, extracellular excretion and intracellular synthesis of esterase were inhibited by adding NaCl in the culture broth. Esterase producing activity gradually increased after late exponential growth phase, until maximum value of 420 mU/ml reached after 64 hours culture period. Esterase of Bacillus sp. KB8 strain was stable up to $50^{\circ}C$ for 30 minutes, but was inactivated by heating for 30 minutes at $70^{\circ}C$. The enzyme activity exponentially decreased during the incubation time at the temperatures of $60^{\circ}C$ and $65^{\circ}C$.

• YAKHAK HOEJI
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• v.11 no.3_4
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• pp.27-32
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• 1967

유화제또는 현탁화제로 쓰이고 있는 hydrophilic polymer의 일종인 acacia및 sodium alginate와 방부제와의 interaction에 관한 연구로서 Higuchi씨등 solubility mehtod를 실험방법으로 하여 고찰하였다. acacia는 용액중에서 혹종의 interation을 하나 o-hydroxybenzoic acid및 p-hydroxybenzoic acid의 methly, ethly, propyl, butyl ester 와는 그러한 interaction이 없다. sodium alginate는 butyl-p-hydroxybenzoate및 o-hydroxybezoic acid를 제외한 본실험에 사용한 방부제와는 용액내에서 interaction을 나타내었다. 방부제의 초농도와 acacia및 sodium alginate를 가하여 일정시간 반응시켜 평형에 도달했을때의 방부제의 농도와의 비인 K치는 acacia및 sodium alginate의 농도와 함수관계에 있음을 발견하였다.