Since submitting the manuscript, we have accumulated a set of 84 parallel measurements of steady state oxygen evolution and the functional content of PSII measured using flash yields (with a solid state optode) and simultaneous FRR chlorophyll fluorescence induction curves, from which we can extract e- PSII-1 s-1, for both Synechococcus and Prochlorococcus cultures. Consistent with the long literature history of such measurements (ex. Suggett et al. 2004, 2009), we observe a good correlation between the two measures of electron transport per PSII. Plotting the FRR estimate of e- PSII-1 s-1 versus the O2 evolution/PSII content estimate of e- PSII-1 s-1 gives a slope of 1.26 and an R2 of 0.58. We have added this information to the Materials and Methods to support our use of FRR estimates of electron transport per PSII. Furthermore, our estimates of ETRmax from FRR induction curves are independently validated by the close correlation between ETRmax and 1/tau, shown in Figure 4A, since 1/tau is derived from the rate constant for the decay of fluorescence after induction, and thus does not depend (computationally) upon our estimator for ETRmax.
This is done for a number of globally significance marine microbes of Syn and Pro lineage.