| abstract |
Provided are mutants PHY1, PHY4 and PHY5 of a wild-type phytase APPA. After being treated for 10 min at 80ºC, the residual enzyme activities of the mutants PHY1, PHY4 and PHY5 are respectively increased by 33.85%, 53.11% and 75.86% compared with that of APPA-M; after being treated for 5 min at 85ºC, the residual enzyme activities of the mutants PHY1, PHY4 and PHY5 are respectively increased by 14.89%, 28.45% and 44.94% compared with that of APPA-M, and the heat resistances thereof are significantly higher than that of APPA-M. |