Extended Data Fig. 1: Relative abundance of heterotrophic and cyanobacterial N2 fixers in the tropical North Atlantic.
From: Rhizobia–diatom symbiosis fixes missing nitrogen in the ocean
a, Relative abundance of ‘Ca. T. diatomicola’ (gamma-A), ‘Ca. T. profundi’, as well as selected cosmopolitan heterotrophic and cyanobacterial N2 fixers5 based on read detection in metagenome data from different size fractions from the tropical North Atlantic. Note that only few known heterotrophic N2 fixers were detected in the dataset, and that ‘Ca. T. diatomicola’ had the highest relative abundance. b, Relative abundance of the most abundant known N2 fixers determined from direct microscopy counts (surface waters of stations 4 and 7 from cruise M161 in the tropical North Atlantic). Note that the metagenome based relative abundances of Trichodesmium in the large size fraction overestimate its microscopy-based abundance by an order of magnitude, most likely due to the polyploidy of this genus94. By contrast, metagenome based relative abundances of Crocosphaera in the large size fraction underestimate its microscopy-based abundance, most likely due to DNA extraction biases95.