한국생물공학회:학술대회논문집
- 2002.04a
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- Pages.457-460
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- 2002
Evaluation and cloning of a (R)-stereospecific esterase from Bacillus stearothermophilus JY144
Abstract
In an effort to isolate novel strains expressing a thermostable esterase that hydrolyzed the rac-ketoprofen ethyl ester to ketoprofen in the stereospecific manner, we screened various soils and composts from broad ecological niches in which the activity was expected to be found. Three hundreds of microbial strains were tested to determine their ester-hydrolyzing activity by using an agar plate containing insoluble tributyrin as an indicative substrate, and then further screened by activity on the (R,S)-ketoprofen ethyl ester. Twenty-six strains were screened primarily at high growth and incubation temperature and further compared the ability to ethyl ester-hydrolyzing activity in terms of conversion yield and chiral specificity. Consequently, a strain JYl44 was isolated as a novel strain that produced a (R)-stereospecific esterase with high stability and systematically identified as a Bacillus stearothermophilus JY144. The enzyme indeed stables at a broad range of temperature, upto 65
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