中文摘要：

本文利用高通量测序及荧光定量PCR技术对南海东北部珠江口盆地柱状沉积物的表层（0-1cm）、中层（20-21 cm）和底层（40-41 cm）3个样品中古菌群落结构及其垂向分布进行了研究。结果表明,沉积物中的古菌主要可被划分为奇古菌门、Woesearchaeota、深古菌门和广古菌门。表层样品中的古菌群落多样性和丰富度最低,类群Marine Group I（MGI）占绝对优势,中层和底层样品中的古菌则以MGI、Group C3、Marine Benthic Group B、Thermoplasmata为主要类群。执行氨氧化功能的亚硝化侏儒菌属（Nitrosopumilus）是研究区域的优势类群,预示该区域的氮代谢过程较为活跃。定量结果表明,古菌丰度为2.00×10^7-8.20×10^7copies/g,且随深度增加呈下降趋势。研究结果可为进一步探讨南海沉积物中的古菌群落特征提供依据。

英文摘要：

In this study, Illumina high-throughput sequencing technology and real-time quantitative PCR （RT-qPCR） were used to profile the archaeal community and vertical distribution in the surface, middle and bottom sediments of Pearl River Mouth Basin in the northeastern South China Sea. The results showed that the majority of arehaeal se- quences were classified into Thanmarchaeota, Woesearchaeota, Bathyarchaeota and Euryarchaeota. The archaeal community diversity and richness in the surface sediment were lowest in three samples, in which Marine Group I （MGI） was most abundant; in contrast, the main groups were MGI, Group C3, Marine Benthic Group B and Ther-moplasmata in the middle and bottom sediments. Interestingly, Nitrosopumilus related to ammonia oxidation was dominant in the sediments, suggesting that nitrogen metabolism was probably active. RT-qPCR results illuminated the abundance of archaea ranging from 2.00 × 10^7 copies/g to 8.20× 10^7copies/g decreasing with the increasing depths. These results will provide a basis for further study of the archaeal community characteristics in the sediments of South China Sea.