【摘要】 研究了几种因素对黑曲霉突变株SA＿13＿20产胞外核糖核酸酶的影响。单次单因子优化,产酶水平提高了170%,最高酶活达1244U mL。研究发现磷酸盐抑制核糖核酸酶的生物合成,但促进菌体的生长,并且该菌产胞外核糖核酸酶不受外源核糖核酸的诱导。确定了最佳碳源,氮源及金属离子源分别为复合碳源(葡萄糖+玉米粉),NH4NO3及K2SO4,最佳菌龄为24h。更多还原

【Abstract】 Effects of culture conditions on extracellular ribonuclease production in flask fermentation by Aspergillus niger SA-13-20 were investigated. A one-factor-at-a-time methodology was employed to optimize the culture conditions for the ribonuclease production. Compared with that under unoptimized conditions, the ribonuclease production increased 170% under the optimized conditions. The maximal ribonuclease production reached to 1244 U/mL. Inorganic phosphate supported cell growth, but repressed enzyme production. The ribonuclease was not inducible when RNA was added to the medium. The optimal carbon and nitrogen source, inorganic salt and inoculum age were complex carbon source （glucose + corn powder）, NH₄NO₃, K₂SO₄, and 24 h, respectively.更多还原