Response Surface Methodological Approach for Optimizing the Expression of Recombinant Ganoderma leucocontextum Immunomodulatory Protein in Pichia pastoris
Jiayi Yang, Pei Qun, Lida Zhang, Juan Lin, Xuanwei Zhou
Ganoderma leucocontextum immunomodulatory protein 2 (FIP-gle2) is a recently identified small molecule
protein. Based on the successful expression of FIP-gle2 in Pichia pastoris GS115, this study optimized the
expression conditions of the engineered P. pastoris using response surface methodology (RSM). Initially,
single-factor experiments determined that the optimal parameters for subsequent optimization were a
cultivation period of 4 days, a temperature range of 26 to 30 °C, an initial pH of 6.0 to 7.0, and a methanol
(MeOH) concentration of 0.75% to 1.25%. Subsequently, a box-behnken design (BBD)-based RSM was
employed, with the total protein concentration in the fermentation broth serving as the detection indicator.
The optimal fermentation conditions were determined to be a cultivation temperature of 27 °C, an initial
pH of 6.7, and a MeOH concentration of 1.11%. Under these conditions, the actual operational parameters
were set at a fermentation temperature of 27 °C, an initial pH of 6.5, and a MeOH concentration of
1%, resulting in an average total protein concentration of 225.12 mg·L-1. This study provides preliminary
optimization of the cultivation conditions for P. pastoris, offering valuable data support for the industrial
production of this protein.
