FIGURE 4.

Simulation of the proportion of dihydrogen taken up by methanogens in co-culture with various fumarate reducers as a function of dissolved H₂ concentration. The simulation was conducted based on a kinetic Michaelis-Menten-wise competition for dihydrogen. Apparent K_m for H₂ uptake were reported by Asanuma et al. (1999). An equal V_max for dihydrogen uptake is assumed. The range of dissolved H₂ concentration is based on Table 1. The sky blue area corresponds approximately to baseline dissolved H₂ concentrations (i.e., in between meals). The salmon area corresponds approximately to H₂ concentration peaks occurring closely after feeding. The purple area corresponds approximately to the range of H₂ concentration that could be observed when methanogenesis is inhibited.