Characterizing the Metabolism of Dehalococcoides with a Constraint-Based Model
Figure 6
Influence of cobalamin on the growth rate and yield of Dehalococcoides.
(A) Growth rate of Dehalococcoides is simulated as a function of both cobalamin salvage rate and cobalamin fraction in the biomass equation. It shows the role of cobalamin in limiting the growth rate of Dehalococcoides. Clearly, the cobalamin uptake or salvage rate at which Dehalococcoides growth is limiting increases with the increase of cobalamin fraction in the biomass. (B) The cost of de novo cobalamin synthesis in terms of Dehalococcoides growth yield is compared (see text for details). The predicted yield of Dehalococcoides with and without the de novo cobalamin synthesis pathway remains almost identical for the reported maximum cobalamin fraction in the biomass. However, the predicted yield decreased only by 4% (from 0.72 gDCW/eeq to 0.69 gDCW/eeq) with 10 fold increase of cobalamin fraction in the biomass indicating the low cost of de novo cobalamin synthesis.