高产腺嘌呤核苷酸菌株的筛选及发酵工艺优化

Screening and fermentation process optimization of high yield adenine nucleotide strain

腺嘌呤核苷酸(AMP)是一种通过竞争苦味受体或截断苦味信号传递的苦味阻滞剂,已经作为一种新型的掩苦方法。为获得安全、稳定的掩苦发酵液,该研究筛选高产腺嘌呤核苷酸菌株,对筛选菌株进行分子生物学鉴定,并通过单因素及响应面试验优化筛选菌株的发酵工艺。结果表明,筛选出一株高产腺嘌呤核苷酸菌株A2,经鉴定菌株A2为赭紫硬孔菌(Rigidoporus vinctus)。最佳发酵工艺条件为玉米粉19 g/L、酵母提取粉5 g/L、KH_(2)PO_(4)2 g/L、装液量120 mL/250 mL,初始pH值为5,发酵时间5 d。在此优化条件下,发酵液中AMP、鸟嘌呤核苷酸(GMP)和次黄嘌呤核苷酸(IMP)含量分别为6.47μg/mL、28.03μg/mL、14.68μg/mL,较未优化前分别提高了98.5%、36.3%、22.6%。

Adenosine monophosphate(AMP)is a bitter blocker that competes for bitter receptors or blocks the transmission of bitter signals,and is used as a new method of masking bitterness.In order to obtain a safe and stable bitter masking fermentation broth,the strain with high adenine nucleotide production was screened and identified by molecular biological technique,and the fermentation process was optimized by single factor and response surface tests.The results showed that a strain A2 with high adenine nucleotide production was screened and identified as Rigidoporus vinctus.The optimal fermentation conditions were corn flour 19 g/L,yeast extract 5 g/L,KH_(2)PO_(4)2 g/L,liquid volume 120 ml/250 ml,initial pH value 5,and fermentation time 5 d.Under the optimized conditions,the contents of AMP,guanosine-5'-monophosphate(GMP)and inosine-5'-monophosphate(IMP)in the fermentation broth were 6.47μg/ml,28.03μg/ml,and 14.68μg/ml,which increased by 98.5%,36.3%and 22.6%,respectively,compared with those before optimization.