Liu Jiwen, Liu Xiaoshou, Wang Min, Qiao Yanlu, Zheng Yanfen, Zhang Xiao-Hua
College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, 266003, Qingdao, China.
Microb Ecol. 2015 Jul;70(1):105-17. doi: 10.1007/s00248-014-0553-8. Epub 2014 Dec 11.
Microbial communities of the Chinese marginal seas have rarely been reported. Here, bacterial and archaeal community structures and abundance in the surface sediment of four sea areas including the Bohai Sea (BS), North Yellow Sea (NYS), South Yellow Sea (SYS), and the north East China Sea (NECS) were surveyed by 16S ribosomal RNA (rRNA) gene pyrosequencing and quantitative PCR. The results showed that microbial communities of the four geographic areas were distinct from each other at the operational taxonomic unit (OTU) level, whereas the microbial communities of the BS, NYS, and SYS were more similar to each other than to the NECS at higher taxonomic levels. Across all samples, Bacteria were numerically dominant relative to Archaea, and among them, Gammaproteobacteria and Euryarchaeota were predominant in the BS, NYS, and SYS, while Deltaproteobacteria and Thaumarchaeota were prevalent in the NECS. The most abundant bacterial genera were putative sulfur oxidizer and sulfate reducer, suggesting that sulfur cycle processes might prevail in these areas, and the high abundance of dsrB (10(7)-10(8) copies g(-1)) in all sites verified the dominance of sulfate reducer in the north Chinese marginal seas. The differences in sediment sources among the sampling areas were potential explanations for the observed microbial community variations. Furthermore, temperature and dissolved oxygen of bottom water were significant environmental factors in determining both bacterial and archaeal communities, whereas chlorophyll a in sediment was significant only in structuring archaeal community. This study presented an outline of benthic microbial communities and provided insights into understanding the biogeochemical cycles in sediments of the north Chinese marginal seas.
中国边缘海的微生物群落鲜有报道。在此，通过16S核糖体RNA（rRNA）基因焦磷酸测序和定量PCR对渤海（BS）、北黄海（NYS）、南黄海（SYS）和东海北部（NECS）四个海域表层沉积物中的细菌和古菌群落结构及丰度进行了调查。结果表明，在操作分类单元（OTU）水平上，这四个地理区域的微生物群落彼此不同，而在较高分类水平上，渤海、北黄海和南黄海的微生物群落彼此之间比与东海北部的更相似。在所有样本中，细菌在数量上相对于古菌占主导地位，其中，γ-变形菌纲和广古菌门在渤海、北黄海和南黄海中占优势，而δ-变形菌纲和奇古菌门在东海北部普遍存在。最丰富的细菌属是推定的硫氧化菌和硫酸盐还原菌，这表明硫循环过程可能在这些区域占主导地位，并且所有站点中dsrB的高丰度（10⁷ - 10⁸拷贝 g⁻¹）证实了硫酸盐还原菌在中国北方边缘海的优势地位。采样区域沉积物来源的差异是观察到的微生物群落变化的潜在解释。此外，底层水的温度和溶解氧是决定细菌和古菌群落的重要环境因素，而沉积物中的叶绿素a仅在构建古菌群落方面具有重要意义。本研究概述了底栖微生物群落，并为理解中国北方边缘海沉积物中的生物地球化学循环提供了见解。
