Optimization of amylase enzyme production by a psychrothrophic Janthinobacterium sp. ATR812 with Response Surface Methodology

Amylases (EC 3.2.1.1) constitute a class of industrial enzymes having great potential for application in industries. Amylase hydrolyses the internal α (1, 4) glycosidase linkages in starch and produces products with lower molecular weight such as glucose, maltose and maltotriose. This research aims the optimization growth and enzyme production in a psychrotolerant bacterium. In the first step, the enzyme production was optimized by one-factor- at- a time method using different variables including temperature, pH, carbon and nitrogen sources, the level of starch, and inoculation rate. In order to examine the interaction between these variables, optimization was performed by response surface method. Molecular identification of strain using 16S rRNA gene showed that bacteria belonged to the genus Janthinobacterium. One-factor-at-a-time method showed that temperature, pH and the level of starch are the most effective factors in enzyme production, the amount of strain production increased to 0.116 U/ml by the mentioned method. The use of response surface methodology increased amylase production up to 0.434 U/ml.