烟草秸秆绿原酸提取工艺优化及其抑菌效果研究

为扩展烟草秸秆的利用途径,探究烟草秸秆绿原酸对烟草疫霉的抑菌效果,采用单因素试验和响应面分析法优化烟草秸秆绿原酸微波辅助提取工艺,并通过离体培养探讨烟草秸秆绿原酸对烟草疫霉菌的抑制作用。单因素及响应面结果表明,烟草秸秆绿原酸最佳提取工艺为料液比1∶15(g·mL^-1),提取温度50.03℃,乙醇体积分数50%,此时粗提物中绿原酸含量为3.48 mg·g^-1;离体条件下,烟草秸秆绿原酸的添加均抑制了疫霉菌的生长,其中175 mg·L^-1烟草秸秆绿原酸对菌落直径的抑制效果最为显著,抑菌率高达32%。此外,碘化丙啶(PI)染色结果表明,175 mg·L^-1的烟草秸秆绿原酸可通过破坏烟草疫霉菌细胞膜的完整性抑制菌丝生长。研究结果为烟草秸秆有效利用和新型天然植物源杀菌剂开发奠定了基础。

Extraction Optimization of Chlorogenic Acid from Tobacco Stalk and Its Antifungal Effect

In order to expand the utilization approach to tobacco stalk, and explore the antibacterial effect of tobacco stalk chlorogenic acid on tobacco Phytophthora, single factor test and response surface analysis were used to optimize the microwave-assisted extraction process of chlorogenic acid from tobacco stalk and isolated culture was applied to explore the antifungal effect of chlorogenic acid on Phytophthora nicotianae. The single factor and response surface results showed that the optimal extraction process conditions were： solid-liquid ratio （g·mL^-1）1∶15, extraction temperature 50.03 ℃, ethanol volume fraction 50%. Under these conditions, the extraction amount of chlorogenic acid in the crude extract reached 3.48 mg·g^-1. In the vitro experiment, the addition tobacco stalk of chlorogenic acid could inhibit the growth of Phytophthora. 175 mg·L^-1 tobacco stalk chlorogenic acid had a significant inhibitory effect on the colony diameter, which reached to 32% of antifungal rate. In addition, propidium iodie （PI） staining showed that 175 mg·L^-1 tobacco stalk chlorogenic acid could inhibit mycelial growth by destroying the integrity of cell membrane of Phytophthora nicotianae. Therefore, above results provided basis for effective utilization of tobacco straw and development of new natural plant fungicides.