Distinct Bottom-Water Bacterial Communities at Methane Seeps With Various Seepage Intensities in Haima, South China Sea
Distinct Bottom-Water Bacterial Communities at Methane Seeps With Various Seepage Intensities in Haima, South China Sea
复制标题
南海海马不同渗流强度的甲烷渗漏底水细菌群落特征
DOI：
10.3389/fmars.2021.753952
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发表时间：
2021-11-15
影响因子：
3.7
通讯作者：
Li，Yazi
中科院分区：
文献类型：
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作者：
Li，Xiaopeng;Dai，Zehan;Li，Yazi
甲烷渗漏是深海环境中的化学合成生态系统。微生物群落结构已被广泛研究的渗漏影响的沉积物和调查以上的水柱渗漏网站仍然缺乏。采用16S核糖体RNA基因测序技术，对中国南海海马不同渗漏强度甲烷渗漏区距海底约50 cm的底层水原核生物群落进行了比较研究。这些地点根据其不同的甲烷含量水平和海底地貌被指定为非渗漏（NS）地点，低强度渗漏（LIS）地点和高强度渗漏（HIS）地点。优势菌门变形菌门、拟杆菌门和放线菌门的丰度在NS和两个渗漏点之间存在显著差异（p < 0.05）。三个地点的Alpha多样性不同，HIS地点的群落多样性最低。主成分分析显示，在三个站点的细菌群落结构高度分歧。许多环境变量，包括温度，碱度，pH值，甲烷，溶解有机碳（DOC）和无机营养盐进行了测量。回归分析表明，甲烷含量是驱动细菌群落变化的关键环境因素（p = 0.001）。线性判别分析效应量分析确定了LIS和HIS站点的各种差异富集属。系统发育分析表明，这些属的操作分类单元与已知的石油降解物种之间的系统发育关系密切，表明海马冷泉可能存在石油渗漏。共现网络表明，微生物相互作用的强度是最弱的HIS网站。这项研究代表了一个全面的比较微生物剖面的水柱冷泉在南海，揭示了渗流强度有很大的影响细菌群落动态。
Methane seeps are chemosynthetic ecosystems in the deep-sea environment. Microbial community structures have been extensively studied in the seepage-affected sediments and investigation in the water column above the seeping sites is still lacking. In this study, prokaryotic communities in the bottom water about 50 cm from the seabed at methane seeps with various seepage intensities in Haima, South China Sea were comparatively studied by using 16S ribosomal RNA gene sequencing. These sites were assigned based on their distinct methane content levels and seafloor landscapes as the non-seepage (NS) site, low-intensity seepage (LIS) site, and high-intensity seepage (HIS) site. The abundances of the dominant phyla Proteobacteria, Bacteroidetes, and Actinobacteria differed significantly between NS and the two seepage sites (p < 0.05). Alpha diversity differed among the three sites with the HIS site showing the lowest community diversity. Principal component analysis revealed highly divergent bacterial community structures at three sites. Many environmental variables including temperature, alkalinity, pH, methane, dissolved organic carbon (DOC), and inorganic nutrients were measured. Redundancy analysis indicated that methane content is the key environmental factor driving bacterial community variation (p = 0.001). Linear discriminant analysis effect size analysis identified various differentially enriched genera at the LIS and HIS sites. Phylogenetic analysis revealed close phylogenetic relationship among the operational taxonomic units of these genera with known oil-degrading species, indicating oil seepage may occur at the Haima cold seeps. Co-occurrence networks indicated that the strength of microbial interactions was weakest at the HIS site. This study represents a comprehensive comparison of microbial profiles in the water column of cold seeps in the SCS, revealing that the seepage intensity has a strong impact on bacterial community dynamics.