Links between Phytoplankton and Bacterial Community Dynamics in a Coastal Marine Environment

Abstract

Bacteria and phytoplankton dynamics are thought to be closely linked in coastal marine environments, with correlations frequently observed between bacterial and phytoplankton biomass. In contrast, little is known about how these communities interact with each other at the species composition level. The purpose of the current study was to analyze bacterial community dynamics in a productive, coastal ecosystem and to determine whether they were related to phytoplankton community dynamics. Near-surface seawater samples were collected in February, May, July, and September 2000 from several stations in the Bay of Fundy. Savin et al. (M.C. Savin et al., Microb Ecol 48: 51-65) analyzed the phytoplankton community in simultaneously collected samples. The attached and free-living bacterial communities were collected by successive filtration onto 5 microm and 0.22 microm pore-size filters, respectively. DNA was extracted from filters and bacterial 16S rRNA gene fragments were amplified and analyzed by denaturing gradient gel electrophoresis (DGGE). DGGE revealed that diversity and temporal variability were lower in the free-living than the attached bacterial community. Both attached and free-living communities were dominated by members of the Roseobacter and Cytophaga groups. Correspondence analysis (CA) ordination diagrams showed similar patterns for the phytoplankton and attached bacterial communities, indicating that shifts in the species composition of these communities were linked. Similarly, canonical CA revealed that the diversity, abundance, and percentage of diatoms in the phytoplankton community accounted for a significant amount of the variability in the attached bacterial community composition. In contrast, ordination analyses did not reveal an association between free-living bacteria and phytoplankton. These results suggest that there are specific interactions between phytoplankton and the bacteria attached to them, and that these interactions influence the composition of both communities.

Seasonal and Spatial Changes of Planktonic Bacterial Communities Inhabiting the Natural Thermal Lake Hévíz, Hungary

“…This method provides the possibility to identify the community members by reamplifying and sequencing of the excised bands. Previously, DGGE technique was successfully applied to reveal the alterations of bacterial or total microbial communities in freshwater and seawater habitats infl uenced by different environmental factors [10,11,12,13,14]. According to the UPGMA dendrogram based on the DGGE patterns, signifi cant seasonal changes with less spatial differences were found among the total planktonic bacterial communities of Lake Hévíz (Fig.…”

Bacterioplankton niche partitioning in the use of phytoplankton-derived dissolved organic carbon: quantity is more important than quality

“…Still, recent advances provided a new look at an old topic: our understanding of DOC-bacteria interaction has moved from an extreme specialization view, where few specific bacterioplankton strains responded to a particular phytoplankton species (for example, González et al, 2000;Schafer et al, 2002;Pinhassi et al, 2004;Grossart et al, 2005;Rooney-Varga et al, 2005;Sapp et al, 2007a) to a more moderate (generalist) and complex view where many types of bacteria are involved in the decomposition of different types of DOCp with differences in their uptake rates (Nelson and Carlson, 2012;Sarmento and Gasol, 2012;Landa et al, 2013;Paver et al, 2013;Morana et al, 2014).…”

Impacts of Mariculture on the Diversity of Bacterial Communities within Intertidal Sediments in the Northeast of China

“…Recently, molecular method-based studies have indicated that bacterial diversity in sediment has been linked with impacts of anthropogenic activities, such as increase of eutrophication and chemical pollution [9][10][11][12][13], changes in species of phytoplankton or zooplankton [14][15][16], and operating a dredging, reclamation, or remediation project [17][18][19][20]. Furthermore, some efforts have been made to study the bacterial community structure dynamics related to mariculture processes.…”