<p>Optimality levels for (A) SYN and (B) FAP as a function of the SYN/FAP biomass ratio across different values of the O<sub>2</sub>/CO<sub>2</sub> flux ratio (C) Comparison of the predicted total community biomass (1/h) for the case when SYN grows sub-optimally and when it grows optimally. Note that, to compute the total community biomass when SYN grows optimally only O<sub>2</sub>/CO<sub>2</sub> flux ratio was fixed at values in the experimentally determined range (i.e., 0.03 to 0.07), whereas for all other cases, in addition to O<sub>2</sub>/CO<sub>2</sub> flux ratio, SYN/FAP biomass ratio was also fixed at values measured experimentally (i.e., 1.5 to 3.5). Lower and upper dashed lines in (C) represent the maximum and minimum predicted community biomass (when SYN grows sub-optimally) across various SYN/FAP biomass ratios.</p
