ABSTRACT

The antifungal activity of volatile organic compounds (VOCs) from 10 Streptomyces isolates was tested using the double-dish chamber method. The VOCs-producing strain S97 exhibited the highest inhibitory effect against Botrytis cinerea mycelium growth. This isolate was identified as Streptomyces sp. with high similarity with Streptomyces lydicus based on morphological and physiological properties, as well as 16S rRNA gene sequence analysis. S97 VOCs analysis was performed by SPME–GC–MS revealing the presence of 14 compounds including three major terpenoids: 3-carene 2,5-dione, geosmin, beta-cubebene and one phenolic compound Phenol, 2-(1,1-dimethylethyl)-6-methyl- representing 43%, 20%, 11% and 9.34% of total produced VOCs, respectively. S97 VOCs inhibited mycelial growth of Rhizoctonia solani and Phoma medicaginis by 95%, Fusarium solani by 69% and Fusarium oxysporum and Sclerotium rolfsii by 20%. The in vivo test carried out on ripe strawberries inoculated by Botrytis cinerea conidia showed that S97 VOCs inhibited the development of grey mould symptoms on fruits by more than 87% compared to untreated control strawberries. Further, light microscope observations revealed 60% swelling and 21% crumbling of B. cinerea conidia when treated with S97 VOCs. Fungal mycelium also showed deep structural alterations with S97 VOCs after 48 h incubation. Strain S97 exhibited strong fumigation potential to control phytopathogenic fungi.

摘要

使用双盘室方法测试了来自 10 种链霉菌属分离株的挥发性有机化合物 (VOC) 的抗真菌活性。产生VOCs的菌株S97对灰葡萄孢菌丝体生长的抑制作用最高。该分离株被鉴定为链霉菌属。与Streptomyces lydicus高度相似基于形态和生理特性，以及 16S rRNA 基因序列分析。通过 SPME-GC-MS 进行的 S97 VOC 分析揭示了 14 种化合物的存在，包括三种主要的萜类化合物：3-carene 2,5-dione、geosmin、β-cubebene 和一种酚类化合物苯酚、2-(1,1-二甲基乙基)-6-甲基-分别占产生的 VOC 总量的 43%、20%、11% 和 9.34%。S97 VOCs 抑制Rhizoctonia solani和Phoma medicaginis的菌丝生长95%，Fusarium solani 69%，Fusarium oxysporum和Sclerotium rolfsii 20%。在体内试验中进行由接种成熟的草莓灰霉病分生孢子表明，与未经处理的对照草莓相比，S97 VOCs 抑制了水果灰霉病症状的发展 87% 以上。此外，光学显微镜观察显示，当用 S97 VOC 处理时，B. cinerea分生孢子膨胀 60%，破碎 21% 。在培养 48 小时后，真菌菌丝体也显示出 S97 VOC 的深层结构改变。菌株 S97 表现出强大的熏蒸潜力，可以控制植物病原真菌。