Thermo-stable, Calcium Independent Alpha Amylase from Two Bacillus species in Afar, Ethiopia
T. W. Atsbha *
Department of Food Science and Technology, Haramaya University, P.O.Box 138, Drie Dawa, Ethiopia
Gulelat D. Haki
Department of Food Science and Technology, Botswana College of Agriculture, University of Botswana, Private Bag 0027, Gaborone, Botswana
S. Abera
Department of Food Science and Technology, Haramaya University, P.O.Box 138, Drie Dawa, Ethiopia
T. B. Gezmu
Center for Food Science and Nutrition, Addis Ababa University, P.O.Box 1176, Addis Ababa, Ethiopia
*Author to whom correspondence should be addressed.
Abstract
Thermostable enzymes play a major role in the food industry. Two isolates (named as TGS1 and TGS2), which were later identified as Bacillus sp., were able to produce alpha amylase at a higher temperature (45-60⁰C). The enzymes from the microorganisms were characterized at different temperatures (45-95⁰C). Enzyme activity at different concentrations of metal ions (Ca2+, Mg2+ and Zn2+) and different times (10-40 minutes) of incubation was also tested. The optimum temperature for the enzyme isolated from TGS1was between 55 and 65⁰C (2.722 and 3.134 U/mg, respectively), while the enzyme from TGS5 was active at temperatures of between 75 and 85⁰C (2.786 and 2.904 U/mg, respectively). Both enzymes were found to be calcium independent.
Keywords: Thermostable amylase, ethiopian hot springs, alpha amylase