Non-random assembly of bacterioplankton communities in the subtropical North Pacific Ocean

Frontiers in Microbiology

Michael S. Rappé¹  Darin H. Hayakawa¹  Alexander eEiler² 

[1] University of Hawaii;Uppsala University;

关键词: Community;    16S rRNA gene;    time series;    oligotrophic;    Assembly;    gyre;   

DOI  :  10.3389/fmicb.2011.00140

来源: DOAJ

【 摘 要 】

The exploration of bacterial diversity in the global ocean has revealed new taxa and previously unrecognized metabolic potential; however, our understanding of what regulates this diversity is limited. Using terminal restriction fragment length polymorphism (T-RFLP) data of bacterial small-subunit ribosomal RNA genes we show that, independent of depth and time, a large fraction of bacterioplankton co-occurrence patterns are non-random in the oligotrophic North Pacific subtropical gyre (NPSG). Pair-wise correlations of all identified operational taxonomic units (OTUs) revealed a high degree of significance, with 6.6% of the pair-wise co-occurrences being negatively correlated and 20.7% of them being positive. The most abundant OTUs, putatively identified as Prochlorococcus, SAR11 and SAR116 bacteria, were among the most correlated OTUs. As expected, bacterial community composition lacked statistically significant patterns of seasonality in the mostly stratified water column except in a few depth horizons of the sunlit surface waters, with higher frequency variations in community structure apparently related to populations associated with the deep chlorophyll maximum. Communities were structured vertically, with a succession from euphotic, mesopelagic, and bathylopelagic populations. Permutation based statistical analyses of T-RFLP data and their corresponding metadata revealed a broad range of putative environmental drivers controlling bacterioplankton community composition in the NPSG, including concentrations of inorganic nutrients and phytoplankton pigment. Together our results suggest that deterministic forces, such as environmental filtering and interactions among taxa, determine bacterioplankton community patterns, and consequently affect ecosystem functions in the NPSG.

【 授权许可】

Unknown