舟山海域好氧不产氧光合异养细菌群落结构分析

STRUCTURE OF AEROBIC ANOXYGENIC PHOTOTROPHIC BACTERIAL COMMUNITY IN ZHOUSHAN ARCHIPELAGO,EAST CHINA SEA

好氧不产氧光合异养细菌(aerobic anoxygenic phototrophic bacteria,AAPB)是广泛分布在各种海洋环境中并在微生物生态学、海洋碳汇和海洋生态系统的生物地球化学循环的过程中具有潜在的重要作用的一类光合异养微生物。于2016年4月份在舟山群岛不同海洋功能区海域的八个站点采集表层海水,基于编码光合反应复合中心小亚基的puf M基因进行高通量测序,对测序结果进行分析,结果发现:除了岱山的样品测序失败以外,其它七个站点共得到192633条序列,我们进行了OTU聚类分析,相似性设为97%,可以看到,所有的数据最后一共分成4051个OTU。属于Proteobacteria的AAPB占明确分类的各细菌门的97%。Rhodobacteraceae科的Loktanella和Roseobacter两个属的AAPB在所有的采样站点中都处于优势地位。Desulfocapsa属在朱家尖站位(ZJJ)的发现非常具有研究价值,在以往的研究中还没有出现过。研究结果表明,在舟山群岛不同功能海域AAPB的群落结构和分布情况也是有差别的,而且与很多环境因素有关,这可以解释为什么目前很难准确预测水生环境总AAPB分布的问题。

Aerobic anoxygenic phototrophic bacteria（AAPB） is a functional bacterial group featuring aerobic and facultative photoheterotrophic abilities and distributes widely.Samples were collected in surface seawater（0.5m） from the Zhoushan Archipelago of the East China Sea in 8 sites representative of 8 functional zones.in April 2016.Water temperature ranged 13.8—17.2℃ and pH 7.65—7.92.Compositions of AAPB community were studied using high-throughput sequencing based on puf M gene.In addition,salinity and dissolved oxygen（DO） were measured in situ and concentrations of inorganic nutrients were determined spectrophotometrically.Diversity index was calculated based on OTU with Mothur and hierarchical clustering of all libraries was built with Qiime.Taxonomic classification was performed using local Blast with Bio Edit.Redundancy analysis（RDA） was carried out using Canoco with the Monte Carlo permutations test.Results show that DO and salinity in Gouqi Island were higher than those of other sites as it was the farthest island offshore.Salinity,concentration of inorganic nitrogen,and total phosphorus fluctuated largely among stations.The community richness of AAPB was in high level as indicated by Shannon and Simpson indices.In total,192 633 clean reads were obtained for 7 stations（except Station DS that failed to read）,and they fell into 4051 OTUs（97% cut-off value）.A total of 32 genera and 7 unclassified genera of Proteobacteria were found.They could be classified into 16 families,15 orders,6 classes,and 3 phyla,of which Roseobacter was dominant genus and Desulfocapsa in Station ZJJ was found for the first time.In abundance and diversity,Proteobacteria ranked the first,followed by Firmicutes and the Planctomycetes.DO and pH were the first and second factors on most of the genera of bacteria as indicated in RDA analysis on microbiological data and environmental parameters.The community structure of AAPB presented different distribution patterns in the Zhoushan Archipelago,and the diversity of AAPB varied with local environmental factors.Therefore,predicting the distribution of total AAPB in aquatic content would be difficult.