ABSTRACT

Microorganisms attached to aquatic steel structures play key roles in nutrient cycling and structural degradation processes. Corrosion-causing microbes are often the focus of studies involving microbially influenced corrosion, yet the roles of remaining community members remain unclear. This study characterizes the composition and functional potential of a ‘core steel microbiome’ across stainless steel types (304 and 316) and historic shipwreck steel along salinity gradients in North Carolina estuaries. We found higher phylogenetic evenness and diversity on steel surfaces compared to sediment, and at lower salinities. The core steel microbiome was composed of heterotrophic generalist taxa, and community composition was most strongly influenced by salinity. Substrate type was a secondary factor becoming more influential at higher salinities. The core steel microbiome included members of Sphingobacteriia, Cytophagia, Anaerolineaceae, Verrucomicrobiaceae, Chitinophagaceae, and Rheinheimera. While salinity differences led to phylogenetic separations across microbial community assemblages, functional genes were conserved across salinity and steel type. Generalist taxa on steel surfaces likely provide functional stability and biofilm protection for the community with limited functional trade-offs compared to surrounding environments. Further, characterization of a core steel microbiome increases the understanding of these complex steel surface microbial communities and their similarities to core microbiomes in other environments.

中文翻译：

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引入“核心钢微生物组”和与微生物影响的腐蚀相关的社区功能分析

摘要

附着在水生钢结构上的微生物在养分循环和结构降解过程中起关键作用。引起腐蚀的微生物通常是涉及受微生物影响的腐蚀的研究重点，但尚不清楚其余社区成员的作用。这项研究描述了北卡罗莱纳州河口沿盐度梯度跨越不锈钢类型（304和316）和历史性沉船钢的“核心钢微生物组”的组成和功能潜力。我们发现，与沉积物相比，钢表面的系统发育均匀性和多样性更高，盐度也更低。核心的钢铁微生物组由异养的通配类群组成，而群落组成受盐度影响最大。基质类型是次要因素，在较高盐度下变得更具影响力。Sphingobacteriia，Cytophagia，Anaerolineaceae，Verrucomicrobiaceae，Chitinophagaceae和Rheinheimera。虽然盐度差异导致整个微生物群落组合之间发生系统发育分离，但功能基因在盐度和钢类型之间均保守。与周围环境相比，钢表面上的通才分类单元可能会为社区提供功能稳定性和生物膜保护，并且在功能上的取舍有限。此外，对核心钢微生物组的表征可增进对这些复杂的钢表面微生物群落及其与其他环境中核心微生物组相似性的了解。