Organic solvent tolerance of halophilic α-amylase from a Haloarchaeon, Haloarcula sp. strain S-1
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A halophilic archaeon, Haloarcula sp. strain S-1, produced extracellular organic solvent-tolerant α-amylase. Molecular mass of the enzyme was estimated to be 70 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This amylase exhibited maximal activity at 50°C in buffer containing 4.3 M NaCl, pH 7.0. Moreover, the enzyme was active and stable in various organic solvents (benzene, toluene, and chloroform, etc.). Activity was not detected at low ionic strengths, but it was detected in the presence of chloroform at low salt concentrations. On the other hand, no activity was detected in the presence of ethyl alcohol and acetone.
KeywordsHaloarcula sp. strain S-1 Halophilic α-amylase Halophilic archaea Organic solvent tolerance Purification
Part of this study has been supported by a grant for the 21st Century’s Center of Excellence Programs organized by the Ministry of Education, Culture, Sports, Science and Technology, Japan, since 2003.
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