Investigation of ?-amylase production by bacillus amyloliquefaciens by using soybean meal

In this study, the effect of medium parameters and required process conditions on ?-amylase enzyme production by Bacillus amyloliquefaciens NRRL B-645 using soybean meal were investigated. Firstly, in addition to soybean meal, the effect of additional carbon sources such as wheat bran, corn protein, hazelnut oil cake and whey on ?-amylase production were investigated. Than, the effect of parameters such as organic and inorganic nitrogen sources, NaCl, inoculum concentration, temperature, shaking speed and initial pH on ?-amylase production were investigated.Natural substrates are used as additional carbon sources such as soybean meal, wheat bran, corn protein, hazelnut oil cake and whey that have a positive effect on enzyme production, were found. Nitrogen sources such as urea, NH4NO3 and NaNO3 have negative effect on enzyme production and decrease activity. Besides medium composition, physical parameters such as temperature and shaking speed have effect on enzyme activity was deduced.Maximum enzyme production was obtained as 4257 U in fermentation medium containing 20 g/l soybean meal, 5 g/l wheat bran, %5 (v/v) whey, 1 g/l peptone, 0.5 g/l yeast extract, 2.5 g/l (NH4)2SO4 at 33 oC and 150 rpm. There was not significant effect of the other medium components on ?-amylase production. This shows that microorganism in different mediums compensate needty of these elements from natural substrate and tap water.