Analysis of Reducing Sugars on Hydrolysis of Cassava Starch by a Themostable a-Amylase from Bacillus stearothemophilus TII12

Abstract

The product of a-amylase hydrolysis was evaluated for their application In sugar syrup Industry. The objectives of this experiment were to determine the enzyme production of Bacillus stearothermophilus TH,2 in a five liter bioreactor and to analyze its hydrolysis product on cassava starch using thin layer chromatography and high performance liquid chromatography. The bacterium was cultured in the bloreactor for 48 hours, and then the biomass, enzyme activity, protein and reducing sugar contents in the filtrate were evaluated In the course of cultivation. The strain secreted an extraceiiuiar a-amylase in the optimal condition at pH 6.5, 5O'C, agitation of 300 rpm and aeration of 1.5 vvm for 24 hours. The highest activity of a.amylase and reducing sugar content of 1 068.87 U/mI and 4.48 g/l respectively were obtained after 24 hours incubation. Hydrolysis products by the crude enzyme on cassava starch were evaluated at different Incubation time. In the course of incubation the content of glucose, dextrin, maltose and oligosaccharides were increasing. After 24 hours the concentration of glucose and maltose reached 51 970 and 10 090 ppm respectively. Based on the enzymatic products, we concluded that thermostabie a.amylsse produced by B. slearothermophilus was aa endo-a-amylase.