Abstract:

Chlorogenic acid is a famous traditional Chinese medicine, mainly extracted from precious medicinal plants. A new method was established with crop-fresh sweet potato（Ipomoea batatas）leaves to produce chlorogenic acid by a strain of Bacillus subtilis RP5 isolated from FlosLonicerae japonicae. HPLC and LC-MS were used to investigate the impact of sweet potato leaves extraction as main liquid culture medium on the yield of chlorogenic acid synthesized by RP5．Results of optimization suggested that the optimal fermentation liquid medium composition was: sucrose 40 g/L，NH4Cl 10 g/L，CuSO4 0.04 g/L, fresh sweet potato leaves (200 g/L). This method indicated that RP5 using sweet potato leaves as material of culture medium could greatly accumule  chlorogenic acid and the yield increased 37.75 mg/L, which was about 23.90 times compared with basal fermentation (1.58 mg/L) of RP5 with potato dextrose broth. The production of total chlorogenic acids including chlorogenic acid and its 2 isomers increased 55.22 mg/L, which was about 31.74 times compared to basal fermentation (1.74 mg/L) of RP5. Using sweet potato leaves with endophytic bacteria to produce chlorogenic acids is first reported herein. This method is simple and can be applied to other materials. The results provided data support for large scale chlorogenic acids production and speeded up the comprehensive utilization of bacteria and sweet potato leaves, and the reasonable development and utilization of crops products .

Key words: chlorogenic acid, sweet potato leaves, fermentation, Bacillus subtilis

摘要： 绿原酸是一种珍贵的传统中药，主要从植物中提取。建立了一种利用农作物-红薯叶发酵枯草芽孢杆菌 RP5产绿原酸的新方法。该株细菌是从金银花中分离得到的一株内生菌，利用高效液相和液质联用方法，研究了红薯叶粗提液作为主要液体培养基对RP5合成绿原酸产量的影响。优化结果表明，最优液体发酵培养基成分为:蔗糖40 g/L、NH4Cl 10 g/L、CuSO40.04 g/L以及新鲜红薯叶200 g/L。该方法表明，RP5使用红薯叶提取物作为主要培养基材料能够导致绿原酸大量积累，RP5发酵产绿原酸产量提高了37.75 mg/L，是RP5基础发酵（1.58 mg/L）的23.90倍。总绿原酸包括绿原酸及其两种同分异构体产量提高了55.22 mg/L，是菌株用PDB发酵（1.74 mg/L）的31.74倍。用红薯叶和内生菌共同发酵产绿原酸这种珍贵的药物是首次报道，该方法简单、迅速且可以应用于其他材料。该结果可为绿原酸的大规模生产提供数据支持，加快了植物内生细菌和红薯叶资源的综合利用，更加快了农作物副产品的合理开发与利用。

关键词: 绿原酸, 红薯叶, 发酵, 芽孢杆菌