Bioprocess for phytase production by Ganoderma sp. MR-56 in different types of bioreactors through submerged cultivation

The aims of this study were to optimize the medium composition, culture conditions and define a bioprocess using types of bioreactor to increase phytase production through submerged cultivation by Ganoderma sp. MR-56. Metal salts, carbon and nitrogen sources had been evaluated upon the overall enzyme production on wheat bran broth. The results showed increase of 81, 95 and 36% of phytase activity, compared to control, by the supplementation of soybean molasses, yeast extract and CaCl2, respectively. Phytase activity in optimized medium reached 14.5 U mL⿿1, a 5.8-fold increase compared to control. Also, at optimized medium, the associated effects of culture conditions as vessel type and aeration were achieved at 30 °C, pH 6.0 and 3% inoculum rate. Maximum phytase production was obtained in Dreschel bottles at 2.0 vvm, which resulted in 20.9 U mL⿿1 at 264 h and productivity of 0.08 U mL⿿1h⿿1, while 11.1 U mL⿿1 in Erlenmeyer Flasks at 96 h (productivity of 0.12 U mL⿿1 h⿿1). The greatest productivity was 0.14 U mL⿿1 h⿿1obtained in stirred tank reactor and reaching 10.3 U mL⿿1 of phytase activity at 72 h. Overall, was proven that Ganoderma sp. MR-56 can successfully produce phytase in different bioreactors through submerged cultivation using a by-product medium.