肌苷产生菌缺失核苷水解酶活性突变株选育及其发酵生产试验

Breeding of B.subtilis Strains with Lack Nucleoside Hydrolyase and their Applicaton to Inosine Production

以枯草芽孢杆菌ＪＳＩＭ－１０１９为出发菌株，经物理、化学诱变剂连续处理，获得一株缺失核苷水解酶活性的突变株ＪＳＩＭ－Ｂ－１９８。该突变株不能降解肌苷，应用于发酵生产中，肌苷产量显著增加。在２０，０００升发酵罐中，连续１０罐批，平均产肌苷１８．３８ｇ／Ｌ，对糖转化率２１．９８％，发酵周期５０ｈ～６０ｈ，该菌株遗传性能稳定，已在工业生产中应用。

An inosine producing strain of Bacillus subtilis JSIM 1019 was mutated by UV ray and EMS repeatedly,then a strain of B.subtilis JSIM B 198 with lack Nucleoside bydrolyase was obtained.The mutant could not hydrolyze the inosine and the inosine accumulation was increased obviously in the fermentation culture.Industrial application of the culture in 20,000 litre fermentors for 10 times demonstrated the stability of the culture. The average inosine concentration was 18.38g/L and the glucose transformation yield was 21.98%.