Fig. 3

Abundance of peptidases and putative peptide transporter proteins of Formosa B. a Proteomic signatures of selected proteases and two putative peptide transporters, which showed an increased expression under laminarin conditions. The two laminarin-induced peptidases shown on the right (00960, 26180) were also detected in the metaproteome of a spring bloom in 2009 (see Supplementary Table S8A). Relative protein abundances are depicted as % riBAQ values. The putative peptidase families and the respective locus tags are indicated. The squares represent the mean values of the three replicates for every protein and each substrate. The error bars refer to the standard error of the mean. Proteins that could be detected in at least two out of three independent biological replicates of each substrate condition are shown (for individual replicate numbers see Supplementary Table S2A). b Comparison of total protein abundances (in %riBAQ) of peptidases (see Supplementary Table S4), nitrogen-associated transporters and the porin (FORMB_11920) in Formosa B under the three investigated substrate conditions (see Supplementary Table S3). c Genomic structure of the porin-encoding cluster and the abundance patterns of the corresponding proteins. Brackets indicate putative operons. Protein functions and the respective locus tags are indicated. GS S: glutamate synthase subunit S, GS L: glutamate synthase subunit L, AT: ammonium transporter, P-II: nitrogen regulatory protein P-II