Optimization of nutritive medium composition for production of amylase by Bacillus strains


  • Yordan Metodiev Stefanov Plovdiv University
  • Ivan Iliev
  • Mariana Marhova
  • Sonya Kostadinova


Bacillus cereus, amylase, enzyme production, nutritive medium optimization


The current study aimed to examine the amylolytic activities of various species of the Bacillus genus. A total of 32% of the tested 166 strains showed a positive reaction on starch agar. Their amylolytic activity was in the range of 0.9 to 2.8 U/ml. Bacillus cereus №10 showed the highest initial activity, established in the late stationary phase of growth (36 hours of incubation). The effects of different nitrogen sources, metal ions and different type of secondary carbon sources (starch was used as a primary carbon source) on the production of amylase by the screened strain were studied. The enzyme production was significantly influenced by the type and concentration of the secondary carbon source. Replacement of peptone by yeast extract and the addition of 1 mM Ca2+ increased initial amylolytic activity by 153% reaching 4.29±0.63 U/ml.





Microbiology, Virology and Immunology