A number of limitations exist for production of human granulocyte colony-stimulating factor (G-CSF) in Pichia pastoris. In this study, two different specific growth rates (0.015 h⁻¹, 0.01 h⁻¹) were used sequentially in the mixed substrate feeding period during methanol induction phase to enhance the G-CSF titer in the culture broth. Necessary parameters required for implementing the feeding strategy, such as specific product yield on biomass (Y_P/X) and maintenance coefficient (m) on glycerol, methanol, and sorbitol were estimated using continuous culture technique. Using this strategy, for the same volumetric productivity, about 20% increase in protein titer was achieved over that obtained from the run carried out at a single pre-set value of 0.015 h⁻¹ alone. Thus, implementation of higher specific growth rate (0.015 h⁻¹) set during initial stages of the methanol induction phase followed by a lower specific growth rate (0.01 h⁻¹) helped in achieving increased protein titers.

在毕赤酵母中生产人粒细胞集落刺激因子 (G-CSF) 存在许多限制。在该研究中，在甲醇诱导阶段的混合底物补料期间依次使用两种不同的特定生长速率（0.015 h ^-1、0.01 h ^-1）以提高培养液中的 G-CSF 滴度。实施饲养策略所需的必要参数，例如生物量的特定产品产量 ( Y _{P / X} ) 和维持系数 ( m) 对甘油、甲醇和山梨糖醇的影响使用连续培养技术进行评估。使用该策略，对于相同的体积生产率，与单独以单一预设值 0.015 h ^-1进行的运行相比，蛋白质效价实现了约 20% 的增加。因此，在甲醇诱导阶段的初始阶段设置更高的特定生长速率（0.015 h ^-1），然后是较低的特定生长速率（0.01 h ^-1）有助于实现增加的蛋白质效价。