Chemical basis of the synergism and antagonism in microbial communities in the nests of leaf-cutting ants
Chemical basis of the synergism and antagonism in microbial communities in the nests of leaf-cutting ants
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DOI：
10.1073/pnas.1008441108
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发表时间：
2011-02-01
影响因子：
11.1
通讯作者：
Spiteller, Dieter
中科院分区：
文献类型：
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作者：
Schoenian, Ilka;Spiteller, Michael;Spiteller, Dieter
切叶蚁培育的真菌Leucoagaricus gongylophorus是它们的主要食物来源。这种共生关系受到微生物病原体的威胁，这些病原体可以严重感染L。具孔的切叶蚁的微生物共生体，主要是假诺卡氏菌和链霉菌，通过提供抗微生物和抗真菌化合物来支持蚂蚁保护真菌花园免受感染。切叶蚁巢穴中微生物的生态作用只有在了解其次级代谢产物的情况下才能详细地加以解决。在这里，我们使用一种方法，通过结合系统发育数据，数据库搜索和液相色谱电喷雾电离高分辨率质谱（LC-ESI-HR-MS）筛选，在生态环境中从微生物中快速鉴定已建立的生物活性化合物。抗霉素A（1）-A（4）、缬氨霉素和放线菌素是以这种方式从切叶蚁的链霉菌共生体中鉴定出来的。基质辅助激光解吸电离（MALDI）成像显示缬氨霉素直接分布在Acromyrmex echinatior工人的体壁。从A. echinatior和A.尼日尔切叶蚁，表明化合物在切叶蚁的巢中发挥其抗微生物和抗真菌潜力。在琼脂扩散法中，观察到了蚂蚁伴生链霉菌产生的次级代谢产物对Escovopsis weberi的强烈协同作用。放线菌素强烈抑制土壤细菌以及其他链霉菌和假诺卡氏菌共生体。抗真菌抗生素不仅对病原真菌有活性，而且对园林真菌也有活性。gongylophorus本身。总之，切叶蚁共生微生物的次级代谢产物有助于切叶蚁巢内微生物群落的形成。
Leaf-cutting ants cultivate the fungus Leucoagaricus gongylophorus, which serves as a major food source. This symbiosis is threatened by microbial pathogens that can severely infect L. gongylophorus. Microbial symbionts of leaf-cutting ants, mainly Pseudonocardia and Streptomyces, support the ants in defending their fungus gardens against infections by supplying antimicrobial and antifungal compounds. The ecological role of microorganisms in the nests of leaf-cutting ants can only be addressed in detail if their secondary metabolites are known. Here, we use an approach for the rapid identification of established bioactive compounds from microorganisms in ecological contexts by combining phylogenetic data, database searches, and liquid chromatography electrospray ionisation high resolution mass spectrometry (LC-ESI-HR-MS) screening. Antimycins A(1)-A(4), valinomycins, and actinomycins were identified in this manner from Streptomyces symbionts of leaf-cutting ants. Matrix-assisted laser desorption ionization (MALDI) imaging revealed the distribution of valinomycin directly on the integument of Acromyrmex echinatior workers. Valinomycins and actinomycins were also directly identified in samples from the waste of A. echinatior and A. niger leaf-cutting ants, suggesting that the compounds exert their antimicrobial and antifungal potential in the nests of leaf-cutting ants. Strong synergistic effects of the secondary metabolites produced by ant-associated Streptomyces were observed in the agar diffusion assay against Escovopsis weberi. Actinomycins strongly inhibit soil bacteria as well as other Streptomyces and Pseudonocardia symbionts. The antifungal antimycins are not only active against pathogenic fungi but also the garden fungus L. gongylophorus itself. In conclusion, secondary metabolites of microbial symbionts of leaf-cutting ants contribute to shaping the microbial communities within the nests of leaf-cutting ants.