Recent studies have revealed multiple roles of insect-associated microbes such as lignin degradation, entomopathogen inhibition, and antibiotic production. These functions improve insect host fitness, and provide a novel source of discovering beneficial microbes for industrial and agricultural production. Previously published research found that in the symbiosis formed by the dipteran pest Delia antiqua (Meigen) (Diptera: Anthomyiidae) and its associated bacteria, the bacteria showed effective inhibition of one fungal entomopathogen, Beauveria bassiana. The antifungal activity of those associated bacteria indicates their potential to be used as biocontrol agents for fungal phytopathogens. In this study, we first isolated and identified bacteria associated with D. antiqua using a culture-dependent method. Second, we tested the antifungal activity of these bacteria against four phytopathogens including Fusarium moniliforme, Botryosphaeria dothidea, and two Fusarium oxysporum strains using the dual-culture method. In total, 74 species belonging to 30 genera, 23 families, eight classes, and four phyla were isolated and identified. Among those bacteria, Ochrobactrum anthropi, Morganella morganii, Arthrobacter sp. 3, and Acinetobacter guillouiae showed significant volatile inhibition activity against F. moniliforme, B. dothidea, and both F. oxysporum, respectively. Moreover, bacteria including Rhodococcus equi, Leucobacter aridicollis, Paenibacillus sp. 3, and Lampropedia sp. showed significant contact inhibition activity against F. moniliforme, B. dothidea, and both F. oxysporum. Our work provides a new source for discovering biocontrol agents against phytopathogens.

中文翻译：

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Delia antiqua (Diptera: Anthomyiidae) 相关细菌对四种植物病原体的拮抗作用

最近的研究揭示了昆虫相关微生物的多种作用，例如木质素降解、昆虫病原体抑制和抗生素生产。这些功能提高了昆虫宿主的适应性，并为发现工业和农业生产中的有益微生物提供了新的来源。先前发表的研究发现，在双翅目害虫 Delia antiqua (Meigen) (Diptera: Anthomyiidae) 及其相关细菌形成的共生体中，该细菌表现出对一种真菌昆虫病原体白僵菌的有效抑制作用。这些相关细菌的抗真菌活性表明它们有可能用作真菌植物病原体的生物防治剂。在这项研究中，我们首先使用培养依赖性方法分离和鉴定了与 D. antiqua 相关的细菌。第二，我们使用双重培养方法测试了这些细菌对四种植物病原体的抗真菌活性，包括串珠镰孢、Botryosphaeria dothidea 和两种尖孢镰刀菌菌株。共分离鉴定出30属23科8纲4门74种。在这些细菌中，Ochrobactrum anthropi、Morganella morganii、Arthrobacter sp。3 和 guillouiae 不动杆菌分别对 F. moniliforme、 B. dothidea 和两种 F. oxysporum 表现出显着的挥发性抑制活性。此外，细菌包括马红球菌、Leucobacter aridicollis、Paenibacillus sp。3，和 Lampropedia sp。对串珠形孢霉、多氏芽孢杆菌和尖孢镰刀菌均表现出显着的接触抑制活性。