‘海螺’望春花内生真菌EF-WCH-51鉴定及其抑制葫芦科刺盘孢活性成分分析

Endophytic fungus EF-WCH-51 from Yulania denudata ‘Hailuo’: strain identification and determination of active component against Colletotrichum orbiculare

摘要:

【背景】药用植物内生真菌产生的次生代谢产物具有多种抗菌活性，因而具有生防菌开发潜力。【目的】鉴定一株对葫芦科刺盘孢(Colletotrichum orbiculare)有抑菌活性的‘海螺’望春花内生真菌EF-WCH-51，并确定其主要抑菌活性成分。【方法】根据形态特征并结合分子序列鉴定EF-WCH-51菌株，利用生长速率法确定EF-WCH-51抑菌活性，并采用半制备型HPLC、HPLC-MS/MS对其活性成分进行分离鉴定。【结果】供试菌株EF-WCH-51为丝枝蜡蚧菌(Lecanicillium aphanocladii)，其发酵液粗提物对葫芦科刺盘孢菌丝生长具有较强抑制作用，EC₅₀为0.086 2 mg/mL；抑菌活性组分A (0.085 0 mg/mL)对葫芦科刺盘孢抑制率达到76.08%，通过查询MS、MS/MS数据库以及与相关文献对比，确定该化合物为卵孢菌素(oosporein)。【结论】本研究发现丝枝蜡蚧菌对葫芦科刺盘孢具有较好的抑菌活性，其主要抑菌活性成分为卵孢菌素，具有作为瓜类炭疽病生防菌株的潜力。

Abstract:

[Background] The endophytic fungi of medicinal plants have good biocontrol potential because the secondary metabolites they produced have a variety of antimicrobial activities. [Objective] To identify an endophytic fungus EF-WCH-51 with inhibitory activity against Colletotrichum orbiculare (a pathogen causing anthracnose of melons) from Yulania denudata ‘Hailuo’ and determine its main antifungal component. [Methods] Strain EF-WCH-51 was identified based on morphological characteristics and molecular sequences. The growth rate method was employed to determine the antifungal activity of EF-WCH-51, and semi-preparative HPLC and HPLC-MS/MS to identify the active component. [Results] Strain EF-WCH-51 was identified as Lecanicillium aphanocladii. The crude extract of its fermentation broth had a strong inhibitory effect on the mycelial growth of C.orbiculare, with EC₅₀ of 0.086 2 mg/mL. The inhibitory rate of the bioactive compound A (0.085 0 mg/mL) against C.orbiculare was 76.08%. The compound was identified as oosporein by data comparison with MS, MS/MS databases and related literature. [Conclusion] L. aphanocladii, with oosporein as the main antifungal active component, had good inhibitory activity against C. orbiculare, demonstrating the potential as a biocontrol strain against C. orbiculare.