毕赤酵母发酵生产重组人血清白蛋白高密度培养条件的研究

研究了毕赤酵母基因工程菌高密度培养条件。在全合成培养基的基础上考察了诱导过程中添加(NH₄)₂SO₄、微量元素PTM₁、油酸、甲醇加量及pH等因素对重组人血清白蛋白表达的影响，发现PTM₁能显著提高白蛋白的表达，6mL/L时蛋白表达量最大。诱导期硫酸铵浓度维持在 3g/L左右蛋白表达量最大，高于3g/L抑制蛋白表达。酸性环境不利于蛋白表达，诱导过程维持pH6.0～6.5最佳。甲醇最佳诱导浓度为10mL/L。添加0.05%的油酸可有效提高蛋白表达。可以此作为发酵罐上发酵培养流加成分的参考。

High density culture conditions of recombinant human serum album from Pichia pastoris

The high density cultivation of a combined strain of producing rHSA(recombinant human serum albumin) from Pichia pastoris was studied. With the same of the synthesized medium, the influences of(NH₄)₂SO₄ ,PTM₁,oleic acid,methanol and pH on the expression of rHSA were investigated. It was discovered that PTM₁ significantly improved the expression of rHSA and the optimum concentration of PTM₁ was 6mL/L. The highest productivity of rHSA was obtained when the concentration of (NH₄)₂SO₄ was 3g/L and the protein expression was depressed when the concentration was higher than 3g/L, in the course of inducement. The optimum concentration of methanol was 10ml/ L,. The expression of rHSA was depressed when pH was lower than 6.0 and the optimum condition was pH 6.0-6.5. Oleic acid improved the protein expression greatly and the optimum concentration was 0.05%n.The above data could be used to direct the fed-batch fermentation.