Members of genus Streptomyces are well known antibiotics producers. Streptomyces sp. are also attractive host cells for heterologous protein production. The aim of our thesis was optimization of production medium for recombinant phytase production in S. rimosus. Currently used production medium for cultivation of S. rimosus is adjusted for antibiotics production. We prepared various mediums and measured phytase activity. Within master thesis we selected from two strains S. rimosu more productive strain e24 for further analysis. We have shown that ratio between soybean flour and starch effect on phytase activity. Low or high concentrations of soybean flour in medium decreased phytase activity regard unaltered production medium. Effect of added glucose depends on concentrations of soybean meal and corn starch and time of cultivation: but in most cases glucose repress phytase production. From all tested added carbon and nitrogen sources positive effect on phytase production have: lactose, dextrin, urea, ammonium sulfate, yeast and casein. We determined optimal concentration of CaCO3, NaCl, zinc, manganese and iron. Phosphate supplement has negative effect on phytase production. In context of the master's thesis we determined the optimal concentration of the individual components of the medium for the recombinant production of phytase.
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