浙江沿海赤潮发生时水体微生物群落

Studies on Microbe Community during Occurrence of Dinoflagellate Blooms in Zhejiang Coastal Sea Area

摘要: 赤潮是当今全球海洋的一大公害，浙江沿海是我国赤潮灾害最为频发和严重的海域。为准确掌握东海近岸海域赤潮发生情况，深入了解东海海域赤潮发生时水体微生物群落，于2018年6月对浙江沿海海域进行了赤潮专项调查。结果发现调查海域氮、磷营养盐含量普遍较高，大多数样品无机氮超一类海水水质标准。调查期间在渔山列岛附近海域发现赤潮，现场叶绿素a含量为42.12 mg/m3，浮游植物细胞丰度为8.16 × 108/L，东海原甲藻丰度占98.5%。应用Illumina MiSeq测序平台对水体微生物进行16s高通量序列测定，共鉴定细菌16门。变形菌门是第一优势门类，其次是蓝细菌和拟杆菌门。比较赤潮发生点及附近海域水体微生物种类组成，双方水体微生物有一定程度的差异。赤潮发生区域第一优势菌为变形菌门占46.1%；附近海域中第一优势菌蓝细菌，占42.0%。

Abstract: Red tide is a major public hazard in the global ocean. Zhejiang coastal area is the most frequent and serious red tide disaster in China. In order to accurately understand the occurrence of red tide and microbial community during the occurrence of the red tide in the East China Sea, ecological environmental studies were implemented in Zhejiang coastal sea area in June 2018. The results showed that nutrient concentrations of N and P were generally high in this area, and DIN concen-trations in most areas exceeded the permitted limit of Chinese seawater quality grade I. Harmful algal bloom (HAB) broke out in Yushan sea area and the causative algae was Prorocentrum donghaiense, with cell density of 8.16 × 108/L and the concentrations of chlorophyll a was 42.12 mg/m3. Metagenomic analysis based on the Illumina Miseq high throughput sequencing technology was applied in investigation area. A total of 16 phyla Bacteria were detected from the samples. Proteobacteria was the dominant group of the total sequences. Other abundant groups include phylum Cyanobacteria and Bacteroidetes. Some differences in bacterial community compositions between HAB and the nearby seawater were observed. The predominant bacteria in the red tide occurrence area were Proteobacteria, comprising 46.1% of the relative abundance, while the predominant bacteria in the nearby sea area comprised 42.0% of the relative abundance.