Bacterioplankton Diversity and Distribution in Relation to Phytoplankton Community Structure in the Ross Sea Surface Waters

Abstract

Primary productivity in the Ross Sea region is characterized by intense phytoplankton blooms whose temporal and spatial distribution are driven by changes in environmental conditions as well as interactions with the bacterioplankton community. However, the number of studies reporting the simultaneous diversity of the phytoplankton and bacterioplankton in Antarctic waters are limited. Here, we report data on the bacterial diversity in relation to phytoplankton community structure in the surface waters of the Ross Sea during the Austral summer 2017. Our results show partially overlapping bacterioplankton communities between the stations located in the Terra Nova Bay (TNB) coastal waters and the Ross Sea Open Waters (RSOWs), with a dominance of members belonging to the bacterial phyla Bacteroidetes and Proteobacteria. In the TNB coastal area, microbial communities were characterized by a higher abundance of sequences related to heterotrophic bacterial genera such as Polaribacter spp., together with higher phytoplankton biomass and higher relative abundance of diatoms. On the contrary, the phytoplankton biomass in the RSOW were lower, with relatively higher contribution of haptophytes and a higher abundance of sequences related to oligotrophic and mixothrophic bacterial groups like the Oligotrophic Marine Gammaproteobacteria (OMG) group and SAR11. We show that the rate of diversity change between the two locations is influenced by both abiotic (salinity and the nitrogen to phosphorus ratio) and biotic (phytoplankton community structure) factors. Our data provide new insight into the coexistence of the bacterioplankton and phytoplankton in Antarctic waters, suggesting that specific rather than random interaction contribute to the organic matter cycling in the Southern Ocean.

Dissecting host‐microbiome interaction effects on phytoplankton microbiome composition and diversity

“…Our findings, which highlight the differential impact on microbiome composition and diversity resulting from innate host selection and host‐microbiome feedback effects, are consistent with previous studies suggesting host control on microbiome assembly and that such control can be modified by host‐microbiome interactions (Mühlenbruch et al, 2018; Shibl et al, 2020). When considering host control, which we tested by manipulating innate host selection microbiome bacterial community composition and diversity are known to change in function of the phytoplankton species, genotypes, bloom phase, and phytoplankton community composition indicating a potential role for phytoplankton host selection on their bacterial microbiome in natural systems (Cordone et al, 2022; Krohn‐Molt et al, 2017; Sison‐Mangus et al, 2016; Zhou et al, 2018). Further, phytoplankton metabolites composition varies between growth stages, where the exponential growth phase is marked by the presence of free amino acids while during the early stationary phase sugar alcohols, mono‐ and disaccharides are more abundant (Kuhlisch et al, 2020).…”

Surface Bacterioplankton Community Structure Crossing the Antarctic Circumpolar Current Fronts

“…PCR conditions were: 5 min at 95 °C, followed by 30 cycles of 95 °C for 30 s, 50 °C for 30 s, 72 °C for 30 s, concluding with an extension at 72 °C for 5 min. The PCR products were analyzed as previously reported [ 38 , 39 ].…”

“…Amplicon sequence variants (ASVs) were estimated through the error profile and assigned taxonomy with the SILVA database (release 138) [ 48 ]. The resulting taxonomic assignments, in combination with variant abundance tables, were used to create a phyloseq object with the phyloseq package [ 49 ], as previously described in [ 38 ]. Subsequently, sequences related to Chloroplasts, Mitochondria, and Eukaryotes, as well as groups related to human pathogens and common DNA extraction contaminants [ 50 ], were removed from the dataset.…”

Discovery of an Abundant Viral Genus in Polar Regions through the Isolation and Genomic Characterization of a New Virus against Oceanospirillaceae

“…They require sodium ions for growth and are widely distributed in marine environments. Although their abundance is usually low, they are often dominant in specific microbial niches, such as the mucus of hermatypic corals and copepods ( 12 , 13 ), algal bloom events in polar regions ( 14 – 16 ), oil-contaminated marine environments ( 17 – 19 ), and the Mariana Trench ( 20 ). This family is also well-known for its ability to degrade hydrocarbons ( 21 – 23 ) and for having complex relationships with algal blooms ( 14 – 16 , 24 ).…”