학술논문
ISOLATION AND CHARACTERIZATION OF A SURFACTANT-STABLE PROTEASE FROM HALOPHILIC BACTERIA Chromohalobacter Japonicus BK-AB18.
Document Type
Article
Author
Source
Subject
*HALOBACTERIUM
*AMMONIUM sulfate
*MOLECULAR weights
*PROTEOLYTIC enzymes
*CASEINS
*ENZYMES
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Language
ISSN
0126-8643
Abstract
The protease from Chromohalobacter japonicus BK-AB18 was produced by growing bacteria in a LB medium containing 5% casein and 5% NaCl. The crude protease was partially purified by three levels of ammonium sulfate concentration (ranges of 0-70%, 70-75% and 75-80%) and the highest specific activity was exhibited in the range of 75-80%. The enzyme has a relative molecular weight of 65 kDa. The protease in this fraction had the highest activity in the following optimum conditions: 7.5% NaCl, a pH of 9.0 and a temperature of 45°C. The activity of the enzyme at the optimum pH and temperature was enhanced by the addition of a Ca2+ ion, but its activity was significantly inhibited by EDTA, hence this enzyme is included as metalloenzyme. Interestingly, the protease activity increased when exposed to a concentration of 0.01% and 0.05% SDS, and was relatively stable in this solution up to a concentration of 10%. It is thus demonstrated that C. japonicus BK-AB18 is a potential source to produce extracellular protease that can be applied in the surfactant/detergent industry. [ABSTRACT FROM AUTHOR]