关键词: 绿原酸, 红薯叶, 发酵, 芽孢杆菌

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