甘草次酸生物合成菌株的筛选与发酵条件优化

甘草是豆科植物的根和根状茎,其生物活性成分甘草次酸具有较大的应用价值。本文对黑曲霉(阿)等食用级菌株进行初、复两轮筛选,得到转化合成甘草次酸能力较强的黑曲霉1株,并通过响应面试验优化该菌生物转化合成甘草次酸的发酵条件,重点针对甘草加量、浓缩苹果汁加量、麸皮的加量及发酵时间进行优化,结果表明:这4种因素对甘草次酸的生产都有较大的影响。优化后的最佳发酵条件为甘草加量9.83%,浓缩苹果汁加量8.05%,麸皮加量9.76%,发酵时间6.79 d。预计18-α甘草次酸产率为0.9256,验证结果与模型和预测值接近。

Screening of Glycyrrhetinic Acid Biosynthetic Strains and Optimization of Fermentation Conditions

Licorice is the root and rhizome of the legumes.Glycyrrhetinic acid,bioactive ingredient in licorice,has great application value.By preliminary screening and rescreening from ediblestrains,this study selected Aspergillus niger,which hasstrong ability toproduce glycyrrhetinic acid.Based on the research of the Response Surface Method,this research optimized the fermentation conditions for Aspergillus niger(A)transforming glycyrrhetinic acid,the factors include content of licorice,content of concentrated apple juice,content of wheat bran and the fermentation time.The results showed these four factors havegreat effect on transformation of glycyrrhetinic acid,and the optimum fermentation conditions were as following:content of licorice was 9.83%,content of concentrated apple juice was 8.05%,content of wheat bran was 9.76%,the fermentation time was 6.79 days and the expected conversion rate of 18-α-glycyrrhetinic acid was 0.9256,the result of verification experiment matched the predicted value.