【摘要】 为提高耐热木聚糖酶DSB和耐热甘露聚糖酶ManB在毕赤酵母GS115中分泌表达的酶活力,选择了3个调控蛋白表达能力较强的启动子P_FLD1,P_GAP和P_TEF1,以P_AOX1为参照,分别在毕赤酵母GS115中进行分泌表达.摇瓶发酵结果表明:P_FLD1,P_TEF1,P_GAP和P_AOX1能有效介导DSB和ManB的分泌,但其胞外酶活相差较大.对于DSB,使用P_AOX1时酶活力明显高于P_FLD1,P_TEF1和P_GAP,最高酶活达846 U/mL;对于ManB,使用P_FLD1时酶活力高于P_AOX1,最高酶活达222 U/mL.故在GS115中分泌表达DSB时选用P_AOX1,而分泌表达ManB时选用P_FLD1.更多还原

【Abstract】 To improve the expression of thermostable xylanase DSB and thermostable mannanase ManB in Pichia pastoris GS115,three strong promoters P_FLD1,P_TEF and P_GAP were chosen and used to regulate the expression of DSB and ManB,using P_AOX1 as a control. The shake-flask fermentation results indicated that P_FLD1,P_TEF,P_GAP and P_AOX1could efficiently control the secretion of DSB and ManB,but their extracellular enzyme activity differed greatly. As for DSB,the enzyme activity of P_AOX1 was much higher than P_FLD1,P_TEF and P_GAP,and the highest enzyme activity reached 846 U/mL. But as for ManB,the enzyme activity of P_FLD1 was higher than P_AOX1 and the highest enzyme activity reached 222 U/mL. Therefore,P_AOX1 was the most efficient promoter for DSB expression and P_FLD1was the most efficient promoter for ManB expression in Pichia pastoris GS115,respectively.更多还原