Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China.
Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China.
Appl Microbiol Biotechnol. 2020 May;104(10):4593-4603. doi: 10.1007/s00253-020-10613-z. Epub 2020 Apr 18.
River-bay system is a transitional zone connecting land and ocean and an important natural source for methane emission. Methanogens play important roles in the global greenhouse gas budget and carbon cycle since they produce methane. The abundance and community assemblage of methanogens in such a dynamic system are not well understood. Here, we used quantitative PCR and high-throughput sequencing of the mcrA gene to investigate the abundance and community composition of methanogens in the Shenzhen River-Bay system, a typical subtropical river-bay system in Southern of China, during the wet and dry seasons. Results showed that mcrA gene abundance was significantly higher in the sediments of river than those of estuary, and was higher in wet season than dry season. Sequences of mcrA gene were mostly assigned to three orders, including Methanosarcinales, Methanomicrobiales, and Methanobacteriales. Specifically, Methanosarcina, Methanosaeta, and Methanobacterium were the most abundant and ubiquitous genera. Methanogenic communities generally clustered according to habitat (river vs. estuary), and salinity was the major factor driving the methanogenic community assemblage. Furthermore, the indicator groups for two habitats were identified. For example, Methanococcoides, Methanoculleus, and Methanogenium preferentially existed in estuarine sediments, whereas Methanomethylovorans, Methanolinea, Methanoregula, and Methanomassiliicoccales were more abundant in riverine sediments, indicating distinct ecological niches. Overall, these findings reveal the distribution patterns of methanogens and expand our understanding of methanogenic community assemblage in the river-bay system. Key Points • Abundance of methanogens was relatively higher in riverine sediments. • Methanogenic community in estuarine habitat separated from that in riverine habitat. • Salinity played a vital role in regulating methanogenic community assemblage.
河流-海湾系统是连接陆地和海洋的过渡带，也是甲烷排放的重要自然源。产甲烷菌在全球温室气体预算和碳循环中起着重要作用，因为它们产生甲烷。在这样一个动态系统中，产甲烷菌的丰度和群落组成还没有得到很好的理解。在这里，我们使用定量 PCR 和高通量测序 mcrA 基因来研究中国南方典型亚热带河流-海湾系统深圳河-海湾系统中产甲烷菌的丰度和群落组成，分别在湿季和干季进行。结果表明，mcrA 基因丰度在河流沉积物中显著高于河口沉积物，在湿季高于干季。mcrA 基因序列主要分为三个目，包括甲烷杆菌目、甲烷微菌目和甲烷杆菌目。具体来说，甲烷八叠球菌、甲烷八叠球菌和甲烷杆菌是最丰富和普遍存在的属。产甲烷菌群通常根据栖息地（河流与河口）聚类，盐度是驱动产甲烷菌群组装的主要因素。此外，还确定了两个栖息地的指示菌群。例如，Methanococcoides、Methanoculleus 和 Methanogenium 优先存在于河口沉积物中，而 Methanomethylovorans、Methanolinea、Methanoregula 和 Methanomassiliicoccales 在河流沉积物中更为丰富，表明存在明显的生态位差异。总的来说，这些发现揭示了产甲烷菌的分布模式，并扩展了我们对河流-海湾系统中产甲烷菌群组装的认识。 关键点 • 河流沉积物中产甲烷菌的丰度相对较高。 • 河口生境中的产甲烷菌群与河流生境中的产甲烷菌群分离。 • 盐度对产甲烷菌群组装起着至关重要的作用。
