Fig. 3: Nitrogen isotope signatures of ancestral nitrogenases.
From: Resurrected nitrogenases recapitulate canonical N-isotope biosignatures over two billion years
a Equations used to calculate fractionation. b Isotopic fractionation was measured for whole cell biomass of ancestral strains compared to WT A. vinelandii. Phylogeny is a subset of Group-I tree modified from Fig. 1B. Branches are not to scale. Bars are the average fractionation value calculated across biological replicates, with exact data points shown as well. Error bars represent ±1 standard deviation. Changes in biomass nitrogen isotope signatures throughout early log (c) and late log to early stationary phase (d) of diazotrophic growth are shown. The straight lines are the linear regressions.
