秦皇岛褐潮暴发敏感海域细菌种群特征

为了掌握细菌种群在褐潮生消过程中的作用,于2013年4—8月采用高通量测序技术调查了秦皇岛近岸海域褐潮暴发敏感海域细菌种群的结构特征. 结果表明:研究区域内细菌种群丰度和多样性在8月最高、5月最低；不同月份水体中细菌种群种类组成及其丰度均存在明显差异,其中第一优势门为变形菌门(Proteobacteria),2013年4月、5月、6月、7月和8月相对丰度分别为46.26%、41.11%、49.69%、38.48%和40.55%；第一优势科为α-变形菌(α-proteobacteria),相对丰度分别为42.20%、34.36%、44.68%、32.17%和28.79%；4月、5月和7月第一优势属为Chloroplast_norank,相对丰度分别为21.48%、16.44%和11.66%；6月第一优势属为Roseobacter_clade_DC5-80-3_lineage,相对丰度为17.85%；8月第一优势属为Candidatus_pelagibacter,相对丰度为15.55%. 典范相关分析(CCA)结果显示,ρ(NO₃-N)、ρ(Chla)和富营养化指数(卡尔森指数,TLI)是研究区域内影响细菌种群结构的主要因素,表明细菌种群结构特征与水体富营养化状态、藻类生物量及其特征密切相关,细菌对研究区域有害赤潮暴发的调节作用还有待进一步研究. 

Bacterial Community Characteristics in Qinhuangdao Coastal Area, Bohai Sea:A Region with Recurrent Brown Tide Outbreaks

In order to understand the roles of the bacterial community in brown tide outbreaks, the bacterial community characteristics in the Qinhuangdao coastal area of Bohai Sea were investigated by pyrosequencing-based approach from April to August 2013. In the studied region, the brown tide has broken out recurrently since 2009. The results showed that the bacterial community had the highest abundance and diversity in August and the lowest value in May. There were clear discrepancies in the species composition and their abundances across months. Proteobacteria was the most predominant phyla, accounting for 46.26%, 41.11%, 49.69%, 38.48% and 40.55% in months from April to August, respectively. α-Proteobacteria was the first predominant class, accounting for 42.20%, 34.36%, 44.68%, 32.17% and 28.79% in months from April to August, respectively. Chloroplast_norank was the first predominant genus in April (21.48%), May (16.44%) and July (11.66%), while Roseobacter_clade_DC5-80-3_lineage became the first predominant genus in June (17.85%) and Candidatus_pelagibacter was the first predominant genus in August (15.55%). Canonical correlation analysis (CCA) suggested that nitrate ρ(NO₃-N), ρ(Chla) and trophic level index (TLI) were the main factors regulating the bacterial community, indicating that there were close relationships among the bacterial community, algal biomass and eutrophication in the studied region. Details of the regulation of the bacterial community to algal community deserve further study.