The importance of short‐chained aliphatic polyamines (PAs) to bacterioplankton‐mediated carbon and nitrogen cycles has been repeatedly proposed. However, bacterial taxa and genes involved in the transformations of different PA compounds and their potential spatial variations remain unclear. This study collected surface bacterioplankton from nearshore, offshore, and open ocean stations in the Gulf of Mexico and examined how metatranscriptomes responded to additions of three single PA model compounds (i.e. putrescine, spermidine, or spermine). Our data showed an overrepresentation of genes affiliated with γ‐glutamylation and spermidine cleavage pathways in metatranscriptomes received PA amendments and the expression level of each pathway varied among different PA compounds and sampling locations. PA‐transforming taxa were affiliated with Actinobacteria, Bacteroidetes, Cyanobacteria, Planctomycetes, and Proteobacteria and their relative importance was also compound and location specific. These findings suggest that PAs are transformed via multiple pathways and by a diversity of marine bacterioplankton in the Gulf of Mexico. The relative importance of different PA transforming pathways and composition of functional microbial communities may be regulated by nutrient status of local environments.

中文翻译：

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墨西哥湾多胺转化细菌浮游生物的转录组学鉴定。

短链脂肪族多胺（PAs）在浮游生物介导的碳和氮循环中的重要性已被反复提出。然而，细菌分类单元和基因参与不同的PA化合物的转化及其潜在的空间变化仍然不清楚。这项研究收集了墨西哥湾近岸，近海和远洋站的表面浮游细菌，并研究了转录组对三种单一PA模型化合物（即腐胺，亚精胺或精胺）添加物的反应。我们的数据显示，在超转录组中，与γ-谷氨酰化和亚精胺裂解途径相关的基因得到了PA修饰，并且每种途径的表达水平在不同的PA化合物和采样位置之间均存在差异。PA转换类群隶属于放线菌，拟杆菌，蓝细菌，菌种和变形杆菌及其相对重要性也具有复合性和位置特异性。这些发现表明，在墨西哥湾，PAs是通过多种途径和多种海洋浮游细菌转化的。不同的PA转化途径和功能性微生物群落组成的相对重要性可能受到当地环境营养状况的调节。