Nitrogen Assimilation Varies Among Clades of Nectar- and Insect-Associated Acinetobacters
Nitrogen Assimilation Varies Among Clades of Nectar- and Insect-Associated Acinetobacters
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DOI：
10.1007/s00248-020-01671-x
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发表时间：
2021-01-06
影响因子：
3.6
通讯作者：
Lievens, Bart
中科院分区：
文献类型：
--
作者：
Alvarez-Perez, Sergio;Tsuji, Kaoru;Lievens, Bart
花蜜通常由酵母和细菌定植，它们的生长在很大程度上取决于它们吸收营养资源的能力，承受高渗透压的能力，以及应对不平衡的碳氮比的能力。尽管这些微生物在花蜜的恶劣环境中取得生态成功的基础仍然知之甚少，但有理由认为它们是有效的氮清除者，可以消耗花蜜中的各种氮源。此外，可以假设系统发育密切相关的菌株比远亲具有更相似的表型特征。我们通过研究从花蜜和蜜蜂中分离的82种不动杆菌在不同富氮基质上的生长性能来验证这些假设，这些不动杆菌代表了五个物种（花蜜不动杆菌、a . boissieri、a . apis和最近描述的分类群a . bareti和a . pollinis）的成员。我们还分析了生长性能和分离株系统发育关系之间的可能联系，同时考虑到它们的地理起源。结果表明，所研究的分离株可以利用多种氮源，包括酵母的常见代谢副产物（如铵和尿素），并且系统发育相关性与所研究的不动杆菌之间氮同化的差异有关。最后，分离物的营养来源和来源（样品类型和国家）也预测了不动杆菌吸收富氮化合物的能力。总的来说，这些结果表明不动杆菌作为氮清除者的潜力在进化间存在差异，并表明营养依赖性可能影响花蜜中细菌和酵母之间的相互作用。
Floral nectar is commonly colonized by yeasts and bacteria, whose growth largely depends on their capacity to assimilate nutrient resources, withstand high osmotic pressures, and cope with unbalanced carbon-to-nitrogen ratios. Although the basis of the ecological success of these microbes in the harsh environment of nectar is still poorly understood, it is reasonable to assume that they are efficient nitrogen scavengers that can consume a wide range of nitrogen sources in nectar. Furthermore, it can be hypothesized that phylogenetically closely related strains have more similar phenotypic characteristics than distant relatives. We tested these hypotheses by investigating the growth performance on different nitrogen-rich substrates of a collection of 82 acinetobacters isolated from nectar and honeybees, representing members of five species (Acinetobacter nectaris, A. boissieri, A. apis, and the recently described taxa A. bareti and A. pollinis). We also analyzed possible links between growth performance and phylogenetic affiliation of the isolates, while taking into account their geographical origin. Results demonstrated that the studied isolates could utilize a wide variety of nitrogen sources, including common metabolic by-products of yeasts (e.g., ammonium and urea), and that phylogenetic relatedness was associated with the variation in nitrogen assimilation among the studied acinetobacters. Finally, nutrient source and the origin (sample type and country) of isolates also predicted the ability of the acinetobacters to assimilate nitrogen-rich compounds. Overall, these results demonstrate inter-clade variation in the potential of the acinetobacters as nitrogen scavengers and suggest that nutritional dependences might influence interactions between bacteria and yeasts in floral nectar.