Fig. 1: Microbial growth and associated changes in available nutrients in the experimental microcosms.
a–c Growth curves under experimental treatments. Each line represents a separate experimental treatment. For each treatment, the added nutrients are denoted as “+” followed by a nutrient symbol of carbon (C), nitrogen (N), phosphorus (Pi), Hfx. volcanii DS2 DNA (H) and E. coli dam−/dcm− DNA (E). Starvation growth curve (S) serves as a control. Error bars represent the standard error of the mean. b Growth curves of the slow-growing microcosms from (a) plotted on a different scale. a, c Two independent sets of experiments. d, e Changes in carbon, nitrogen and phosphorus after the microbial growth has stopped. The plotted changes are mean values from two experimental replicates. The experimental treatments (X axis) are grouped into three categories based on whether carbon and/or nitrogen were provided. Nutrient abbreviations: TOC, total organic carbon; TN, total nitrogen; TP, total phosphorus; Pi, inorganic phosphorus. Organic phosphorus (Po) was computed as by subtracting Pi from TP. For “+Pi” treatment, the calculated value of Po is replaced with an asterisk, due to errors associated with measurements of TP and Pi for that treatment. Actual values for the measured nutrient concentrations and the associated calculations are shown in Supplementary Tables S1 and S2.
