کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
35235 | 45082 | 2009 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Production, purification, and characterization of two extremely halotolerant, thermostable, and alkali-stable α-amylases from Chromohalobacter sp. TVSP 101 Production, purification, and characterization of two extremely halotolerant, thermostable, and alkali-stable α-amylases from Chromohalobacter sp. TVSP 101](/preview/png/35235.png)
The halophilic bacterial strain Chromohalobacter sp. TVSP 101 was shown to produce extracellular, halotolerant, alkali-stable and moderately thermophilic α-amylase activity. The culture conditions for higher amylase production were optimized with respect to NaCl, pH, temperature and substrates. Maximum amylase production was achieved in a medium containing 20% NaCl or 15% KCl at pH 9.0 and 37 °C in the presence of 0.5% rice flour and tryptone. Addition of 50 mM CaCl2 to the medium increased amylase production by 29%. Two kinds of amylase activity, designated amylase I and amylase II, were purified from culture filtrates to homogeneity with molecular masses of 72 and 62 kDa, respectively. Both enzymes had maximal activity at pH 9.0 and 65 °C in the presence of 0–20% (w/v) NaCl but amylase I was much more stable in the absence of NaCl than amylase II. The enzymes efficiently hydrolyzed carbohydrates to yield maltotetraose, maltotriose, maltose, and glucose as the end products.
Journal: Process Biochemistry - Volume 44, Issue 2, February 2009, Pages 210–215