大叶藻(Zostera marina)海草床沉积物细菌和古菌丰度及组成的垂直剖面特征  

Vertical patterns of bacterial and archaeal abundance and community structure in seagrass(Zostera marina) meadow sediments

作　　者：郑鹏飞[1,2] 张晓黎 龚骏 ZHENG Peng-Fei;ZHANG Xiao-Li;GONG Jun(Key Laboratory of Coastal Environmental Processes and Ecological Remediation,Chinese Academy of Sciences,Yantai Institute of Coastal Zone Research,Chinese Academy of Sciences,Yantai,Shandong 264003,China;University of Chinese Academy of Sciences,Beijing,Beijing 100049,China;School of Marine Sciences,Sun Yat-Sen University,Zhuhai,Guangdong 519082,China)

机构地区：[1]中国科学院海岸带环境过程与生态修复重点实验室,中国科学院烟台海岸带研究所,山东烟台264003 [2]中国科学院大学,北京100049 [3]中山大学海洋科学学院,广东珠海519082

出　　处：《微生物学通报》2020年第6期1662-1674,共13页Microbiology China

基　　金：中国科学院A类战略性先导科技专项(XDA23050303);中国科学院前沿科学重点研究项目(QYZDB-SSW-DQC013,QYZDB-SSW-DQC041);国家自然科学基金(41676154,41976115)。

摘　　要：【背景】海草床是重要的"蓝碳"生态系统,对全球碳汇有重要贡献。海草床沉积物剖面的垂直梯度特征显著,表层呈现氧化态,富含活性有机质,而深层呈还原态,以惰性有机质为主。【目的】探究这种垂直特征如何影响微生物的丰度和群落分布。【方法】利用荧光定量PCR和16SrRNA基因高通量测序等手段,测定了山东荣成天鹅湖大叶藻海草床不同深度(5、10、15、20、25和30 cm)沉积物中细菌和古菌丰度、多样性和群落结构的变化。【结果】细菌和古菌16S rRNA基因拷贝数随深度的增加而降低,在沉积物5cm深处,细菌的16SrRNA基因拷贝数显著高于20cm和30cm层(ANOVA,P<0.05)。深度对细菌和古菌α多样性指数没有显著影响(P>0.05)。细菌中相对丰度最高的是变形菌门,其次是绿弯菌门,拟杆菌门,浮霉菌门等,其中δ-变形菌和浮霉菌的相对丰度随深度显著增加(P<0.05)。古菌群落中深古菌门比例最高,在25cm深处达到70%以上;其次是乌斯菌门、洛基古菌门、广古菌门和奇古菌门等。奇古菌门比例随深度增加而显著降低(P<0.05),其他古菌类群在不同深度间差异不显著(P>0.05)。【结论】海草床沉积物细菌和古菌的丰度、多样性和群落分布具有明显的垂直特征,这种特征可能受沉积物有机质组成和氧化还原状况影响。[Background]The seagrass meadow was a"Blue carbon"ecosystem contributing greatly to global carbon sequestration in coastal sediments.The vertical profile of seagrass sediments exhibits a strong redox gradient,where the surface layer was oxic and rich in labile organic matters and the deeper layer was reduced and dominated by recalcitrant organic matters.[Objective]We hypothesized that bacterial and archaeal communities varied greatly in abundance and community structure along the vertical gradient in the seagrass sediments.[Methods]Quantitative real-time PCR and high-throughput sequencing were applied to characterize the prokaryotic communities at different sediment depths(5,10,15,20,25 and 30 cm)in the Zostera marina dominated meadow.[Results]The 16 S rRNA gene copy numbers of bacteria and archaea decreased with the increasing sediment depth,and the bacterial copy numbers in the 5-cm layer was significantly higher than those in the 20-cm and 30-cm layers(ANOVA test,P<0.05).Depth had no significant effect on bacterial and archaealαdiversity indices(P>0.05).The most dominant bacterial phylum was Proteobacteria,followed by Chloroflexi,Bacteroidetes,and Planctomycetes.The relative abundances ofδ-Proteobacteria and Planctomycetes were significantly increased with increasing depth(P<0.05).Bathyarchaeota was the most dominant archaeal phylum,accounting for 70%in the 25-cm layer.Other abundant archaeal phyla were Woesearchaeota,Lokiarchaeota,Euryarchaeota and Thaumarchaeota.The relative abundance of Thaumarchaeota decreased significantly with increasing depth(P<0.05).[Conclusion]The benthic archaeal and bacterial communities in the seagrass meadow sediments exhibited obvious vertical characteristic,which could be driven by organic matter composition and sediment redox status.

关 键 词：海草床 垂直剖面 微生物群落结构 丰度 多样性 

分 类 号：Q938.8[生物学—微生物学]