College of Environmental & Resources Sciences, Zhejiang University, Hangzhou 310058, China.
Key Laboratory of Coastal Environment and Resources of Zhejiang Province, School of Engineering, Westlake University, Hangzhou 310030, Zhejiang, China.
Environ Sci Technol. 2024 Sep 10;58(36):16040-16054. doi: 10.1021/acs.est.4c02321. Epub 2024 Aug 8.
Ammonia-oxidizing archaea (AOA) are widely distributed in marine and terrestrial habitats, contributing significantly to global nitrogen and carbon cycles. However, their genomic diversity, ecological niches, and metabolic potentials in the anoxic intertidal aquifers remain poorly understood. Here, we discovered and named a novel AOA genus, Nitrosomaritimum, from the intertidal aquifers of Yancheng Wetland, showing close metagenomic abundance to the previously acknowledged dominant AOA. Further construction of ammonia monooxygenase-based phylogeny demonstrated the widespread distribution of AOA in global estuarine-coastal niches and marine sediment. Niche differentiation among sublineages of this new genus in anoxic intertidal aquifers is driven by salinity and dissolved oxygen gradients. Comparative genomics revealed that Nitrosomaritimum has the genetic capacity to utilize urea and possesses high-affinity phosphate transporter systems () for surviving phosphorus-limited conditions. Additionally, it contains putative genes encoding nitrous-oxide (NO) reductase for reducing NO to nitrogen gas. Furthermore, we gained first genomic insights into the archaeal phylum populations residing in intertidal aquifers and revealed their potential hydroxylamine-detoxification mutualism with AOA through utilizing the AOA-released extracellular hydroxylamine using hydroxylamine oxidoreductase. Together, this study unravels the overlooked role of priorly unknown but abundant AOA lineages of the newly discovered genus Nitrosomaritimum in biological nitrogen transformation and their potential for nitrogen pollution mitigation in coastal environments.
氨氧化古菌（AOA）广泛分布于海洋和陆地生境中，对全球氮碳循环具有重要贡献。然而，它们在缺氧潮间带含水层中的基因组多样性、生态位和代谢潜能仍知之甚少。在这里，我们从盐城湿地的潮间带含水层中发现并命名了一个新型的氨氧化古菌属，Nitrosomaritimum，其丰度与先前公认的优势氨氧化古菌属密切相关。进一步构建基于氨单加氧酶的系统发育树表明，氨氧化古菌在全球河口-沿海生境中广泛分布，并存在于海洋沉积物中。该新属的不同亚群在缺氧潮间带含水层中的生态位分化是由盐度和溶解氧梯度驱动的。比较基因组学揭示，Nitrosomaritimum 具有利用尿素的遗传能力，并拥有高亲和力的磷酸盐转运系统（），以适应磷限制条件。此外，它还包含编码亚硝酸盐（NO）还原酶的基因，用于将 NO 还原为氮气。此外，我们首次获得了关于居住在潮间带含水层中的古菌门种群的基因组见解，并通过利用氨氧化古菌释放的细胞外羟胺，揭示了它们与氨氧化古菌通过羟胺氧化还原酶进行潜在的羟胺解毒共生关系。总的来说，这项研究揭示了先前未知但丰富的氨氧化古菌谱系在生物氮转化中的被忽视的作用，以及它们在沿海环境中减轻氮污染的潜力。
