Temperature and salinity drive comammox community composition in mangrove ecosystems across southeastern China
Temperature and salinity drive comammox community composition in mangrove ecosystems across southeastern China
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温度和盐度影响中国东南部红树林生态系统的comammox群落组成
DOI：
10.1016/j.scitotenv.2020.140456
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发表时间：
2020-11-10
影响因子：
9.8
通讯作者：
Li, Meng
中科院分区：
文献类型：
--
作者：
Liu, Zongbao;Zhang, Cuijing;Li, Meng
完全氨氧化（comammox）微生物是在自然和工程生态系统中发现的新发现的硝化细菌。红树林生态系统是氮循环的热点，但对这些生态系统中共生菌的多样性和丰度，特别是驱动因素的了解很少。本文利用深度测序技术研究了中国东南部6个红树林生态系统的共蛾多样性。结果表明，红树林沉积物中的共生菌种类繁多。系统发育分析表明，在Glade a中存在一个新的comammox类群，该类群在没有参考序列的情况下形成了一个独特的聚类，表明其潜在的独特性。定量PCR结果显示，comammox丰度略高于典型氨氧化细菌，但显著低于氨氧化古菌，表明它们不是红树林生态系统中优势的氨氧化剂。变异分区分析表明，沿地理距离，群落相似性显著降低，地理因子和沉积物属性对群落微生物组成和氨氧化剂丰度变化有显著影响。温度和盐度是形成comammox群落的最重要因素。此外，在极高盐度的沉积物中检测到多种comammox微生物，表明该群落可以适应高盐度环境，这表明盐度可能不是导致开放海洋环境中没有comammox微生物的关键因素。本研究扩展了目前对红树生态系统中小蚁的多样性和生态位偏好的认识，并进一步增强了我们对小蚁群落适应潜力的认识。(C) 2020 Elsevier B.V.版权所有
Complete ammonia-oxidizing (comammox) microorganisms are newly recognized nitrifying bacteria found in natural and engineered ecosystems. Mangrove ecosystems are hotspots for nitrogen cycling, but the knowledge of comammox diversity and abundance, and particularly, driving factors, in these ecosystems is scarce. We here used deep sequencing to investigate comammox diversity in six mangrove ecosystems across southeastern China. Our results showed that comammox microorganisms in mangrove sediments were extremely diverse. Phylogenetic analysis revealed a novel comammox group within Glade A that formed a distinct cluster for which no reference sequence existed, implying their potential uniqueness. Quantitative PCR demonstrated that comammox abundance was slightly higher than that of the canonical ammonia-oxidizing bacteria but significantly lower than that of ammonia-oxidizing archaea, indicating they are not the dominant ammonia oxidizers in mangrove ecosystems. Finally, variation partition analysis revealed a significant decrease in similarity of comammox communities along the geographical distance, and a pronounced effect of the geographic factors and sediment attributes on the composition of comammox microorganisms and the abundance variations of ammonia oxidizers. Temperature and salinity were the most important contributing factors that shaped the comammox community. Further, detection of diverse comammox microorganisms in extremely high-salinity sediments suggested that this community could adapt to high salinity environments, which indicates salinity may not be a critical factor resulting in the absence of comammox microorganisms in open-ocean environments. This study expanded the current understanding of the diversity and niche preference of comammox in mangrove ecosystems, and further enhanced our understanding of adaptation potential of comammox communities. (C) 2020 Elsevier B.V. All rights reserved.