枯草芽孢杆菌二步发酵法生产5'-肌苷酸

摘要

5'-Monophosphate (5'-IMP) plays an important role in food additive industry since it is an indispensable component of flavor enhancer.To shorten the period and lower the cost of 5 '-IMP production,characteristic of acid phosphotranferase (AP/PTase) from Morganella morganii was studied and its encoding gene was cloned to inosine-producing strain Bacillus subtilis JG to obtain Bacillus subtilis JAB and Bacillus subtilis JAF.Then according to the character of inosine production and phosphotranferase expression by the two strains,5'-IMP production by twostep fermentation combined with inosine accumulation and enzyme catalysis was achieved.The final production of 5'-IMP by the two strains was 2.4 g/L and 3.0 g/L,respectively.This study provided new insights into 5'-IMP production that used fermentation products as substrates.%5'-肌苷酸作为新一代增味剂的重要组成成分,在调味品行业具有十分重要的地位.为进一步缩短5'-肌苷酸生产周期,降低生产成本,在研究来源于摩氏摩根菌Morganella morganii的酸性磷酸酶AP/PTaseM催化条件基础上,将该酶编码基因phoCYM克隆至肌苷生产菌株Bacillus subtilis JG,获得B.subtilis JAB和B.subtilis JAF,并根据重组菌株合成肌苷及表达酸性磷酸酶的特性,通过调控发酵条件实现了肌苷发酵和酶催化相偶联的二步发酵法生产5'-肌苷酸.经摇瓶发酵实验验证,两菌株5'-肌苷酸产量分别为2.4 g/L和3.0 g/L.