Isolation of bacteria producing feed additive amylase enzymes

In this thesis, α-amylase producing Bacillus strains ZF4 and A4 were isolated from the soil samples collected from Çukurova University campus area. Bacillus sp. ZF4 α-amylase showed its maximum activity at pH 6.0 and 40 °C, while Bacillus sp. A4 α-amylase at pH 8.0 and 40-50 °C, respectively. ZF4 α-amylase retained all its activity after 15 minutes of pre-incubation at 70 °C, while lost its activity rapidly over temperature values. A4 α-amylase, on the other hand, maintained its activity up to 70 °C, and experienced a rapid loss of activity after 80 °C. ZF4 α-amylase reached its highest activity level at 48 hours after bacterial inoculation, while A4 α-amylase reached its highest activity at 24 hours. While both enzymes reached higher activity levels compared to the control group in the presence of SDS and Co, CaCl2, MgCl2 and EDTA showed inhibitory effects for both enzymes. Finally, zymogram analysis revealed that molecular weight of both enzymes is approximately 105.4 kDa.