长江口及邻近海域海水细菌多样性及时空分布规律研究

发布时间：2018-06-28 15:03

本文选题：长江口 + 细菌多样性　；参考：《浙江海洋大学》2017年硕士论文

【摘要】：本文采用DAPI染色计数、构建细菌克隆文库和高通量测序技术等方法,对长江口及邻近海域表层海水中的细菌丰度、群落结构组成及时空分布规律进行了研究,并同时监测相应的环境指标,分析了细菌群落结构变化与环境因子的关系。首先,通过DAPI染色计数和克隆文库法研究长江口及邻近海域大面站10个站点表层海水中的细菌。结果显示长江口及邻近海域表层海水中细菌丰度总体较高,但生物量变化较大,总体趋势从长江口向外海增加。细菌克隆文库分析表明:共发现11个细菌门类,分别为变形菌门、拟杆菌门、放线菌门、蓝细菌门、厚壁菌门、绿弯菌门、酸杆菌门、浮霉菌门、疣微菌门、纤维杆菌门和柔膜菌门,其中变形菌门为主要优势类群(60.61%),其次是拟杆菌门(15.18%)和放线菌门(14.79%),另外柔膜菌门和SAR类群在研究海域中比较少见。MDS和聚类分析将10个采样点的细菌群落组成分为6类。RDA分析表明TP、DO、pH和TSP是影响浮游细菌群落结构的主要环境因子。多样性分析结果显示长江口及邻近海域部分站点中细菌多样性显著,与研究海域水产养殖活动有关,并受到区域洋流和海洋化学环境(如低氧带)的影响。从长江口及邻近海域D03连续站采集9个表层海水样品,通过DAPI染色计数和高通量测序的方法,对样品中细菌丰度和群落结构的昼夜变化进行研究。结果表明海水中细菌丰度总体较高,但呈现出白天稍高于夜间的现象,pH和PO43-是细菌丰度昼夜变化的重要影响因子。本次共发现28个门类的细菌,主要包括变形菌门、拟杆菌门、放线菌门、蓝细菌门、SAR406、疣微菌门、柔膜菌门、绿弯菌门、酸杆菌门和一些丰度极低的类群,其中变形菌门是各样品的优势类群,其次为拟杆菌门和放线菌门。各细菌类群在昼夜波动下的变化趋势不同,影响细菌群落结构变化的因素主要有潮汐、光照、营养盐、浮游动物的摄食和病毒的裂解等。这些研究结果充分说明了长江口海域表层海水中具有较高的细菌多样性水平,细菌群落结构随昼夜周期的变化规律及影响因素十分复杂。
[Abstract]:In this paper, the bacterial abundance, community structure and temporal and spatial distribution in the surface water of the Changjiang Estuary and its adjacent waters were studied by means of DAPI staining counting, bacterial clone library construction and high-throughput sequencing techniques. At the same time, the relationship between the change of bacterial community structure and environmental factors was analyzed. First, the bacteria in the surface water of 10 stations in the Changjiang Estuary and adjacent waters were studied by DAPI staining counting and clone library method. The results showed that the abundance of bacteria in the surface water of the Changjiang Estuary and its adjacent waters was higher, but the biomass changed greatly, and the general trend increased from the Changjiang Estuary to the offshore sea. The analysis of bacterial clone library showed that there were 11 kinds of bacteria, namely Proteus, Bacteroides, Actinomycetes, Cyanophyta, Thinacea, Chlorophyta, Acidobacterium, floatula, Verruca, Microphylum. Phylum cellulosus and phylum pilosum, Proteus was the main dominant group (60.61%), followed by Bacteroides (15.18%) and Actinomycetes (14.79%). Class. RDA analysis showed that TP DOA pH and tsp were the main environmental factors affecting the phytoplankton community structure. The results of diversity analysis show that the diversity of bacteria in the Yangtze Estuary and some stations in the adjacent sea area is significant, which is related to the aquaculture activities in the study area and is affected by the regional ocean currents and marine chemical environment (such as the hypoxic zone). Nine surface sea water samples were collected from D03 continuous station in Changjiang Estuary and adjacent waters. The diurnal variation of bacterial abundance and community structure in the samples were studied by DAPI staining counting and high-throughput sequencing. The results showed that the bacterial abundance in seawater was higher than that in night, but pH and PO43- were important factors influencing the diurnal variation of bacterial abundance. A total of 28 species of bacteria were found, including Proteus, Bacteroides, Actinomycetes, Cyanobacterium SAR406, Microphylum verruca, phylum flexnerosa, Chlorophyta, Bacillus acidosa, and some very low abundance groups. The phylum Proteus was the dominant group of the samples, followed by Bacteroides and Actinomycetes. The variation trend of bacteria groups was different under the fluctuation of day and night. The main factors influencing the change of bacterial community structure were tidal light nutrient salt zooplankton feeding and virus cracking. These results fully show that there is a high level of bacterial diversity in the surface seawater of the Yangtze Estuary, and the variation of bacterial community structure with the circadian cycle and the influencing factors are very complex.
【学位授予单位】：浙江海洋大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：Q938.8

【相似文献】