重组人干扰素ω在对数生长期毕赤酵母中的高效表达特性研究

用不同比生长速率μ的毕赤酵母探讨其表达外源重组蛋白的差异性,通过起始pH值、甲醇诱导浓度和周期、菌体浓度、装液量等实验,优化具有较高μ的对数生长期毕赤酵母表达rhIFNω的摇瓶条件。结果表明,μ对毕赤酵母表达rhIFNω有显著影响。μ为0.1612h-1的毕赤酵母表达rhIFNω最高为558mg/L,较μ为0.1321、0.0505和0.0052h-1的毕赤酵母分别提高50%、68%和99%。对数生长期的毕赤酵母表达rhIFNω的最适摇瓶表达条件为:250mL摇瓶装入30mL BMMY,控制菌体浓度达到200~300g/L(WCW),起始pH值自然,每24h添加甲醇15g/L一次,诱导表达周期为4d。通过表达条件的优化,rhIFNω的表达量达到1070mg/L,较优化前提高149%。

High-level expression behaviors of recombinant human interferon omega in logarithm phrase Pichia pastoris

Expression difference of heterologous recombinant protein in Pichia pastoris with different specific growth rate (mu) was observed. The expression conditions of recombinant human interferon omega (rhIFN(omega)) in logarithm phrase Pichia pastoris with higher mu were optimized by shake flask tests under various initial pH, methanol concentration, duration of the induction, cell density, and medium volume. The results showed that there were prominent influences of mu on expression of rhlFN(omega). The maximum yield of rhIFN(omega) in the Pichia pastoris with mu of 0.1612 h(-1) was 558 mg/L. However, these in the Pichia pastoris with mu of 0.1321, 0.0505 and 0.0052 h(-1) were reduced by 50%, 68% and 99%, respectively. In 250 mL shake flask, the optimal medium volume, cell density, initial pH, methanol concentration, frequency and duration of methanol induction were 30 mL, 200 - 300 g/L (WCW), natural, 15 g/L, 1 time in every 24h and 4d, respectively. Under the optimal expression condition, the maximum yield of rhIFN(omega) in logarithm phrase Pichia pastoris was 1070 mg/L which was increased by 149% more than that under the initial condition.