Diversity and abundance of diazotrophic microorganisms in the South China Sea during intermonsoon
Diversity and abundance of diazotrophic microorganisms in the South China Sea during intermonsoon
复制标题
DOI：
10.1038/ismej.2008.51
复制
发表时间：
2008-09-01
期刊：
影响因子：
11
通讯作者：
Zehr, Jonathan P.
中科院分区：
文献类型：
--
作者：
Moisander, Pia H.;Beinart, Roxanne A.;Zehr, Jonathan P.
对南海越南沿岸海域固氮生物多样性和丰度的空间异质性进行了研究。研究区域从湄公河羽状流延伸到大陆架区域，并延伸到1700米深的站点。基于nifH基因多样性的南海固氮生物群落中，有与大洋、河口、盐沼和微生物垫群落序列密切相关的组分。稀疏分析表明，通过使用97%的相似性操作分类单位的定义，在样品中的nifH序列多样性的大部分被所获得的384个nifH克隆所覆盖。回收的大部分nifH序列分为两个簇：一个由束毛菌属序列组成，另一个由α-变形菌群组成。单细胞蓝藻群A和B，共生丝状蓝藻固氮菌零星检测。束毛藻是迄今为止最丰富的固氮生物，每升有高达6 × 10（5）nifH基因拷贝。设计定量PCR探针-引物组并用于定量两种变形菌群，揭示了高达10（3）-10（4）nifH基因拷贝/升的丰度，其中透光区的丰度最高。克隆文库的主要组分也通过nifH微阵列和多维标度（MDS）分析揭示。MDS显示，来自0- 5-m深度的> 10 μ m大小部分的样品与其余样品分开聚类，主要是由于束毛藻序列的丰度。南海固氮生物群落的多样性相对较低，是河口和海洋指纹的混合体。
The spatial heterogeneity of diversity and abundance of diazotrophs were investigated off the Vietnamese coast in the South China Sea (SCS). The study area extended from the Mekong River plume to the shelf region and beyond to stations extending to 1700m depth. The SCS diazotroph community, based on nifH gene diversity, had components closely related to sequences from open ocean, estuarine, saltmarsh and microbial mat communities. Rarefaction analysis suggested that by using a 97% similarity operational taxonomic unit definition, the majority of nifH sequence diversity in the samples was covered by the 384 nifH clones obtained. The majority of the nifH sequences recovered fell into two clusters: one comprised of Trichodesmium sequences and the other an alpha-proteobacterial group. Unicellular cyanobacterial groups A and B, and symbiotic filamentous cyanobacterial diazotrophs were detected sporadically. Trichodesmium was by far the most abundant diazotroph, with up to 6 x 10(5) nifH gene copies per liter. Quantitative PCR probe-primer sets were designed and used to quantify two proteobacterial groups, revealing abundances up to 10(3)-10(4) nifH gene copies per liter, with the highest abundances in the photic zone. Major components of the clone library were also revealed by a nifH microarray and multidimensional scaling (MDS) analysis. MDS showed that samples from the > 10 mu m size fraction from 0- to 5-m depths clustered separately from the rest of the samples, primarily due to the abundance of Trichodesmium sequences. The SCS diazotroph community has a relatively low diversity and is a mixture of both estuarine and oceanic fingerprints.