Fig. 3: Carrying capacity and type of interactions.

A Growth curves of experiment E1, arrows showing the days where cell numbers were counted by flow cytometry (see also Supplementary Table S1). Axenic curves shown are from all Prochlorococcus strains. Thick lines represent mean fluorescence. B Total calculated N biomass of the cultures in E1 on days 60 and 100 in μmol N/L. Dashed line indicates total available N in co-cultures. C Log2 Fold Change (log2FC) of Alteromonas N biomass relative to axenic Alteromonas controls on days 60 and 100. Asterisks indicate statistically significant FC (Bonferroni corrected ANOVA p < 0.05). ALT Alteromonas, PRO Prochlorococcus, Au arbitrary units.