【摘要】 以肌苷生产菌枯草芽孢杆菌（Bacillus subtilis）TF₂为受体菌,利用质粒DNA的原生质体转化法,将携带糖化型α-淀粉酶基因的重组质粒pBX96导入肌苷产生菌TF₂中,转化频率为5.7×10^-6,获得一株能以淀粉为碳源生产肌苷的转化子T140（pBX96）,该工程菌株能在以淀粉为碳源的培养基上平均积累肌苷4.64g/L,经过92代,质粒自发丢失率为0.78％。培养48h后,工程菌株的糖化型α—淀粉酶活力为受体菌的7.79倍。并对工程菌株TI40（pBX96）的发酵条件做了初步摸索。更多还原

【Abstract】 Inosine-producing strain Bacillus subtilis TF2 was used as recipient. By means of protoplast transformation, pBX96 containing saccharifying typeα-amylase gene was transformed to TF2, with frepuency of transformation was 5.7×10-6. An engineering strain TI40(pBX96), which can utilize starch as the carbon source to produce inosine and accumulate an average of 4.64 g/L inosine, was obtained. After 92 generation, the frequency of plasmid-free cells was 0.78%. After 48 hours, the activity of the saccharifying type aaaaa-amylase of the transformant is 7.79 times more than TF2. The condition of the fermentation of the transformant TF40 (pBX96) was studied.更多还原