专性互惠担子菌真菌,Leucocoprinusgongylophorus,用植物物质中的碳介导切叶蚁的营养。此外,真菌花园和肠道根瘤菌中的重氮营养肠杆菌被认为介导了大气氮的同化,和中胚层属的内胚层,以及其他尚未识别的菌株,据推测,蚂蚁从植物物质中吸收其他化合物,如柠檬酸盐,果糖,和氨基酸。一起,这些营养伙伴将支持高产量的切叶生物质的生产。在目前的调查中,我们认为Ralstonia属中有三种系统发育上不同且可培养的重氮生物,甲基杆菌,假单胞菌整合了这个共生的营养网络,促进蚂蚁对氮的营养。这些属的菌株通常从蚂蚁腹部的16SrRNA文库中分离并直接测序,以及非重氮生物不动杆菌和短杆菌属。这五个分离株在图书馆中代表性不足,表明它们在体内都不占优势。Liberibacter属的四种未培养的根瘤菌菌株占主导地位,Terasakiella,巴尔通菌和,仅在Acromyrmex蚂蚁中,由中胚层属的胚乳。Acromyrmex还呈递了少量的另外两种未培养的盘生菌菌株,支原体和螺旋体。Atta工人中不存在原生质细菌,这表明与这些细菌的关联对于蚂蚁生物质生产不是强制性的。我们在南美蚂蚁中检测到的大多数菌株在遗传上与先前描述的来自中美洲和北美的切叶机的菌株相似,表明广泛的地理分散,并建议使用固定的生态服务。
The obligate mutualistic basidiomycete fungus, Leucocoprinus gongylophorus, mediates nutrition of leaf-cutting ants with carbons from vegetal matter. In addition, diazotrophic Enterobacteriales in the fungus garden and intestinal Rhizobiales supposedly mediate assimilation of atmospheric nitrogen, and Entomoplasmatales in the genus Mesoplasma, as well as other yet unidentified strains, supposedly mediate ant assimilation of other compounds from vegetal matter, such as citrate, fructose, and amino acids. Together, these nutritional partners would support the production of high yields of leafcutter biomass. In the present investigation, we propose that three phylogenetically distinct and culturable diazotrophs in the genera Ralstonia, Methylobacterium, and Pseudomonas integrate this symbiotic nutrition network, facilitating ant nutrition on nitrogen. Strains in these genera were often isolated and directly sequenced in 16S rRNA libraries from the ant abdomen, together with the nondiazotrophs Acinetobacter and Brachybacterium. These five isolates were underrepresented in libraries, suggesting that none of them is dominant in vivo. Libraries have been dominated by four uncultured Rhizobiales strains in the genera Liberibacter, Terasakiella, and Bartonella and, only in Acromyrmex ants, by the Entomoplasmatales in the genus Mesoplasma. Acromyrmex also presented small amounts of two other uncultured Entomoplasmatales strains, Entomoplasma and Spiroplasma. The absence of Entomoplasmatales in Atta workers implicates that the association with these bacteria is not mandatory for ant biomass production. Most of the strains that we detected in South American ants were genetically similar with strains previously described in association with leafcutters from Central and North America, indicating wide geographic dispersion, and suggesting fixed ecological services.