Abstract
Although phytoplankton are the major source of marine dissolved organic matter (DOM), their blooms are a global problem that can greatly affect marine ecological systems, especially free-living bacteria, which are the primary DOM degraders. In this study, we analyzed free-living bacterial communities from Xiamen sea during an Akashiwo sanguine bloom using Illumina MiSeq sequencing of 16S rRNA gene amplicons. The bloom was probably stimulated by low salinity and ended after abatement of eutrophication pollution. A total of 658,446 sequence reads and 11,807 OTUs were obtained in both bloom and control samples with Alpha-proteobacteria and Gamma-proteobacteria being the predominant classes detected. The bloom decreased bacterial diversity, increased species evenness, and significantly changed the bacterial community structure. Bacterial communities within the bloom were more homogeneous than those within the control area. The bacteria stimulated by this bloom included the SAR86 and SAR116 clades and the AEGEAN-169 marine group, but a few were suppressed. In addition, many bacteria known to be associated with phytoplankton were detected only in the bloom samples. This study revealed the great influence of an A. sanguinea bloom on free-living bacterial communities, and provided new insights into the relationship between bacteria and A. sanguinea in marine ecosystems.
Highlights
Illumina sequencing-based analysis of free-living bacterial community dynamics during an Akashiwo sanguine bloom in Xiamen sea, China
These studies reveal the close relationship between specific phytoplankton blooms and their associated bacterial communities, and which bacterial species may be crucial for the regulation of bloom dynamics and succession
A relatively large number (5,601) of OTUs failed to be assigned into any genus with a confidence level higher than 50% (Table 1), suggesting the presence of many potentially novel bacteria in the sea area near Xiamen
Summary
Illumina sequencing-based analysis of free-living bacterial community dynamics during an Akashiwo sanguine bloom in Xiamen sea, China. Many molecular tools have been utilized to investigate bacterial communities associated with phytoplankton blooms, such as 16S ribosomal DNA (rDNA) clone libraries[18], polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE)[11,19], flow cytometry[20], terminal restriction fragment length polymorphism[18], fluorescence in situ hybridization[21,22], metatranscriptomics[23] and high-throughput sequencing[24,25]. These studies reveal the close relationship between specific phytoplankton blooms and their associated bacterial communities, and which bacterial species may be crucial for the regulation of bloom dynamics and succession. The high-throughput sequencing technologies have developed quickly in recent years, and Illumina MiSeq sequencing has become the most popular since it can generate a multi-million sequence reads of partial 16S rRNA genes to meet the throughput demands of environmental microbial ecology studies and reduce cost[27]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
