Production of α-Amylase from Bacillus megaterium MD-1

Abstract

The alpha-amylase is used extensively in many different industrial sectors and is renowned for modifying starch by rupturing 1-4 glycosidic bands. Depending on the intrinsic properties of the microorganism, several alpha-amylases with thermostable and halotolerant properties are expressed. In the current study, the bacteria were isolated from Ergani Makam Mountain. Identification and optimization of the isolated bacteria were performed. As a result of the 16S rRNA analysis, physiological, morphological and biochemical analyis were carried out for the identification of the isolated microorganism and consequently the bacterium was defined as Bacillus megaterium MD-1. Following its identification, α-Amylase, was isolated from B. megaterium. Optimal conditions for bacteria and enzyme production were determined as 48 hours, 35°C and pH 7.0. Maximum enzyme activity was optained at 40°C and pH 8.0. The effects of various carbon and nitrogen sources on enzyme production were investigated by adding to the nutrient medium. Compared to the control regarding enzyme production, it was determined that carbon sources, particularly sucrose, fructose and lactose inhibited enzyme production by 75%, no change on the other hand was observed in glucose, starch and galactose. It was also observed that urea and sodium nitrate from nitrogen sources had an inhibitory effect on enzyme production whereas other nitrogen sources did not. The highest amylase production among nitrogen sources was obtained with peptone addition. In our study, it was determined that an increase in amylase activity could be achieved by using the optimum values of physical parameters.