Yin Xingjia, Chen Hui, Jiang Kaixi, Zhang Boda, Li Ruohong, Zhu Xinzhe, Sun Lianpeng, Ng Zhi Lin, Su Ming
School of Marine Sciences, Sun Yat-Sen University & Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, China.
Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Zhuhai 519082, China.
Microorganisms. 2024 Sep 16;12(9):1901. doi: 10.3390/microorganisms12091901.
Nitrogen-cycling processes in the deep sea remain understudied. This study investigates the distribution of nitrogen-cycling microbial communities in the deep-sea surface sediments of the western South China Sea, using metagenomic sequencing and real-time fluorescent quantitative PCR techniques to analyze their composition and abundance, and the effects of 11 environmental parameters, including NH-N, NO-N, NO-N, PO-P, total nitrogen (TN), total organic carbon (TOC), C/N ratio, pH, electrical conductivity (EC), SO, and Cl. The phylum- and species-level microbial community compositions show that five sites can be grouped as a major cluster, with sites S1 and S9 forming a sub-cluster, and sites S13, S19, and S26 forming the other; whereas sites S3 and S5 constitute a separate cluster. This is also evident for nitrogen-cycling functional genes, where their abundance is influenced by distinct environmental conditions, including water depths (shallower at sites S1 and S9 against deeper at sites S13, S19, and S26) and unique geological features (sites S3 and S5), whereas the vertical distribution of nitrogen-cycling gene abundance generally shows a decreasing trend against sediment depth. Redundancy analysis (RDA) exploring the correlation between the 11 environmental parameters and microbial communities revealed that the NO-N, C/N ratio, and TN significantly affect microbial community composition ( < 0.05). This study assesses the survival strategies of microorganisms within deep-sea surface sediments and their role in the marine nitrogen cycle.
深海中的氮循环过程仍未得到充分研究。本研究调查了南海西部深海表层沉积物中氮循环微生物群落的分布，采用宏基因组测序和实时荧光定量PCR技术分析其组成和丰度，以及包括NH-N、NO-N、NO-N、PO-P、总氮（TN）、总有机碳（TOC）、C/N比、pH、电导率（EC）、SO和Cl在内的11个环境参数的影响。门水平和物种水平的微生物群落组成表明，五个位点可归为一个主要聚类，其中位点S1和S9形成一个子聚类，位点S13、S19和S26形成另一个子聚类；而位点S3和S5构成一个单独的聚类。这在氮循环功能基因方面也很明显，其丰度受不同环境条件的影响，包括水深（S1和S9位点较浅，而S13、S19和S26位点较深）和独特的地质特征（S3和S5位点），而氮循环基因丰度的垂直分布通常随沉积物深度呈下降趋势。探索11个环境参数与微生物群落之间相关性的冗余分析（RDA）表明，NO-N、C/N比和TN显著影响微生物群落组成（<0.05）。本研究评估了深海表层沉积物中微生物的生存策略及其在海洋氮循环中的作用。
