Dissolved storage glycans shaped the community composition of abundant bacterioplankton clades during a North Sea spring phytoplankton bloom

In 2020 we sampled a complete spring bloom in the German Bight over a 90-day period. Bacterioplankton metagenomes from 30 time-points allowed reconstruction of 251 metagenome-assembled genomes (MAGs). Corresponding metatranscriptomes highlighted 50 particularly active MAGs of the most abundant clades. Saccharide measurements together with bacterial polysaccharide utilization loci (PUL) expression data identified β-glucans (diatom laminarin) and α-glucans as the most prominent dissolved polysaccharide substrates metabolized by the bacterioplankton. Here we are depositing all supporting environmental data for the analyzed  2020 Helgoland spring algal bloom. This includes physicochemical data, data on algal abundances and biovolumes, data on copepod and flagellate abundances, data on monosaccharide and antibody-based polysaccharide measurements, and 16S rRNA-based bacterial diversity data. The corresponding metagenome, metatranscriptome and MAG sequence data of this project are available from the European Nucleotide Archive (accession PRJEB52999).