摘要:Phytase production by Pichiapastoris was used as a case to study the mechanism and strategy for optimization of heterologous protein production. It was found that the ratio of inducer-methanol to cell concentration had a significant influence on phytase production. In this case, we found that the optimum initial cell concentration and methanol concentration were 85 g/L and 10 g/L, respectively. During induction period, an easy-to-control methanol feeding method was proposed according to the optimal ratio of methanol to cell concentration at a range of 0.063 -0.132 g/g, and phytase activity and productivity reached 53984 U/mL and 529.25 U/(mL·h), respectively. The method for optimization of phytase production through controlling the optimal ratio maybe provide an alternative idea to enhance other heterologous protein production with P. pastoris.