黄河口潮间带沉积物细菌群落结构特征

Abstract

选取黄河口潮间带有植被覆盖和无植被覆盖两个区域采集柱状沉积物，利用实时荧光定量PCR技术和高通量测序技术分析有无植被覆盖沉积物中的细菌群落特征和功能差异，探究影响潮间带细菌群落结构的主要环境因子。结果显示，细菌丰度在有植被区域大于无植被区域。沉积物中细菌群落丰富度和多样性在有植被区域随深度的增加而增加，而在无植被区域其最高值出现在沉积物中层（14-16 cm）。两个区域在门分类水平上以变形菌（Proteobacteria）、绿弯菌（Chloroflexi）、放线菌（Actinobacteria）和酸杆菌（Acidobacteria）为主；属分类水平上的优势类群为芽孢杆菌（Bacillus）、苍白杆菌（Ochrobactrum）、拟无枝菌酸菌（Amycolatopsis）和鞘脂单胞菌（Sphingomonas）等。相关性分析发现盐度和亚硝酸盐浓度对细菌群落多样性和丰富度影响显著。功能预测分析表明，有植被区域沉积物细菌在氨基酸代谢、膜运输和碳水化合物代谢方面功能活跃，而无植被区域细菌则在核酸复制和修复、能量代谢过程方面更为活跃。;In this study, the sediment cores were collected from two areas with or without vegetation covering in the intertidal zone of the Yellow River estuary, in which the characteristics and functional differences of bacterial community were analyzed based on real-time fluorescent quantitative PCR and high-throughput sequencing. The mainly environmental influencing factors were also explored. Results showed that the bacterial abundance from the vegetation area was higher than that from the vegetation-free area. The richness and diversity of bacterial community increased with the depth in the vegetation area, while they were the highest in the sample of middle layer (14-16 cm) in the vegetation-free area. The shared dominant phyla in both areas were Proteobacteria, Chloroflexi, Actinobacteria and Acidobacteria. The dominant genera were Bacillus, Ochrobactrum, Amycolatopsis, Sphingomonas and so on. The results of correlation analysis showed that salinity and nitrite concentration were the main influencing factors of the richness and diversity of bacterial community. The functional prediction analysis showed that the processes of bacterial membrane transport, amino acid metabolism and carbohydrate metabolism in the vegetation area were more active, while the processes of bacterial DNA replication, repairing and energy metabolism in the vegetation-free area were more active.