The bloom-forming cyanobacterium Nodularia spumigena CENA596 encodes the
biosynthetic gene clusters (BGCs) of the known natural products nodularins, spumigins,
anabaenopeptins/namalides, aeruginosins, mycosporin-like amino acids, and scytonemin, along
with the terpenoid geosmin. Targeted metabolomics confirmed the production of these metabolic
compounds, except for the alkaloid scytonemin. Genome mining of N. spumigena CENA596 and its
three closely related Nodularia strains—two planktonic strains from the Baltic Sea and one benthic
strain from Japanese marine sediment—revealed that the number of BGCs in planktonic strains was
higher than in benthic one. Geosmin—a volatile compound with unpleasant taste and odor—was
unique to the Brazilian strain CENA596. Automatic annotation of the genomes using subsystems
technology revealed a related number of coding sequences and functional roles. Orthologs from the
Nodularia genomes are involved in the primary and secondary metabolisms. Phylogenomic analysis
of N. spumigena CENA596 based on 120 conserved protein sequences positioned this strain close to the
Baltic Nodularia. Phylogeny of the 16S rRNA genes separated the Brazilian CENA596 strain from those
of the Baltic Sea, despite their high sequence identities (99% identity, 100% coverage). The comparative
analysis among planktic Nodularia strains showed that their genomes were considerably similar
despite their geographically distant origin.
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