Investigation of alpha-amylase corn starch hydrolysis process enzyme activity during

ABSTRACT The rapid enhancement of many biotechnology processes has been severely constrained by enzyme deactivation. An improved knowledge of enzyme deactivation would significantly enhance the feasibility of quite a few biotechnological processes. Starch has become a very important biopolymer and is used in many industries as a feedstock material. Enzymes are used to quickly transform starch molecules to useful, added-value biochemicals. a-Amylase enzyme is known to effectively attack both insoluble starch and starch granules held in aqueous suspension. Before designing a successful hydrolysis system, maintain a good activity of the a-amylase enzyme which is not degragaded during the process is important. Because, the loss of enzyme activity will significantly affect the process yield. In the present study, corn starch is hydrolysed with a-amylase enzyme which is produced from Bacillus Species. The degree of corn starch hydrolysis (%) and residual a-amylase activity (%) were investigated versus temperature, pH, impeller speed, processing time, enzyme concentration, viscosity, amount of hydrolysate added, maltose concentration, glycose concentration, amount of ethanole added and CaCfe concentration. And also, the mathematical models which represent the residual starch concentration and residual a- amylase activity were developed according to the data obtained from the experiments. The hydrolysis reactions were carried out in a modular bioreactor system in 500 ml of aqueous solutions containing 1 % (w/v) corn starch. An evaluation of the experimental data showed that residual activity of a-amylase enzyme and hydrolysis degree of corn starch studied were different for each set of these conditions. Keywords: Corn starch, enzymatic hydrolysis, process variables IX