Global-scale distributions of marine surface bacterioplankton groups along gradients of salinity, temperature, and chlorophyll: a meta-analysis of fluorescence in situ hybridization studies

Abstract

We used literature data on marine bacterial (sub)group abundances, as determined by fluorescence in situ hybridization, to test whether the ecological variability of the different subgroups was similar to that of the bacterial community as a whole. Patterns of 6 major groups are described (Alpha-, Beta-, Gammaproteobacteria and Bacteroidetes, as well as Rhodobacteraceae and SAR11) and related to environmental variables such as chlorophyll a (chl a) concentration, salinity, and temperature, distinguishing between coastal or open-ocean environments. Coastal ecosystems exhibited higher relative abundances (average % of DAPI counts) of Bacteroidetes (23%), Beta-(11%) and Gammaproteobacteria (10%), and Rhodobacteraceae (6%), while significantly higher contributions of Alphaproteobacteria and SAR11 (32%) were on average enumerated offshore. Multiple regression analyses showed significant explanatory power of chl a and temperature on total and SAR11 absolute abundances (expressed as cells ml −1 ), and of chl a and salinity levels on absolute abundances of Betaproteobacteria and Rhodobacteraceae. Other analyses revealed increasing contribution of Gammaproteobacteria for increasing temperatures and high temperature avoidance for Betaproteobacteria. Significantly different log-log regression slopes were found between bacterial group absolute abundances and chl a concentration at a global scale, ranging from 0.13 ± 0.04 (SE) for SAR11 to 0.53 ± 0.08 for Betaproteobacteria. The different patterns observed for the different groups, in coastal and open-ocean environments, suggest different niche preferences by each group as well as a coherent response to environmental factors.

Phylogenetic Signals of Salinity and Season in Bacterial Community Composition Across the Salinity Gradient of the Baltic Sea

“…Marine waters are dominated by Alpha - and Gammaproteobacteria , and limnetic areas by Actinobacteria and Betaproteobacteria (Kirchman et al, 2005; Logares et al, 2009; Lefort and Gasol, 2013). The typical abundance shift of Cyanobacteria as well as changes in bacterial community composition and richness between July and February were also observed in this study (Fuhrman et al, 2008; Fortunato and Crump, 2015), with the dataset showing that both salinity-related and seasonal differences caused phylogenetically clustered shifts in bacterial community composition.…”

Diversity and abundance of “Pelagibacterales” (SAR11) in the Baltic Sea salinity gradient

“…The stable phylogenetic lineages of the "Pelagibacterales" exhibit distinct spatio-temporal abundance patterns in the water column [5,16,[20][21][22]]. An amplicon sequencing study of samples from the Baltic Sea demonstrated shifts in the relative abundance of amplicon sequencing reads from subclade SAR11-I to subclade SAR-IIIa in the transition from marine to oligohaline conditions [12].…”

Exploring Microdiversity in Novel Kordia sp. (Bacteroidetes) with Proteorhodopsin from the Tropical Indian Ocean via Single Amplified Genomes

“…Bacteroidetes is a cosmopolitan phylum that typically constitutes between 4 and 22% of marine bacterioplankton cells (Glöckner et al, 1999; Cottrell and Kirchman, 2000; Alonso-Sáez et al, 2007; Ruiz-González et al, 2012; Lefort and Gasol, 2013; Acinas et al, 2014). The relative abundance of Bacteroidetes can reach up to 53% and it often correlates with phytoplankton blooms (Abell and Bowman, 2005; Fandino et al, 2005).…”