Investigation of amylase production potentials of mesophilicbacteria

Amylases are enzymes that can be produced in intracellular and extracellular forms by various eukaryotic and prokaryotic organisms. In addition to the simple and economical enzyme production conditions, bacteria are more advantageous than other organisms in industrial amylase production because they can be manipulated when necessary. According to this; two different strains of mesophilic bacteria (B. megaterium A1 and B. pumilus D3) were first tested at various incubation temperatures (25-60 °C), shaking speeds (0-200 rpm), initial pH (pH 4.0-10.0) and incubation times (24, 48 and 72 hours) and optimum amylase production conditions were determined in this thesis study. Following the optimization studies, both strains of bacteria were also incubated separately in liquid growth media to which inducers such as xylose, glucose, lactose and maltose were added at the rate of 0.1-0.4% under optimum conditions. As a result of these processes, both the effects of the tested inducer substances on the amylase production of both bacterial strains and the inducer amounts that increased the enzyme production at the highest rate were determined. In order to increase the amylase production of bacterial strains, 0.1-0.3% of rice powder and raw potato extract were also added separately to the liquid growth media and the effects of these substances on enzyme production were investigated. In the studies of this thesis, the effects of inducer mixtures in optimum concentrations on amylase productions of both bacterial strains were also investigated. Furthermore, studies on starch hydrolysis in solid media were carried out in the aim to determine whether both bacterial strains tested produce amylase in solid media. In addition, the presence of the synthesized amylases on the gel was also proven as a result of the zymogram analysis performed in natural polyacrylamide gel electrophoresis of culture fluids obtained from media (0.3% xylose+0.3% glucose) where the highest amylase production of both bacterial strains occurred. Keywords: Amylase, Bacillus megaterium A1, Bacillus pumilus D3, Inducer, Mesophilic bacterium, Synergistic effect