Mechanistic model of nutrient uptake explains dichotomy between marine oligotrophic and copiotrophic bacteria
Fig 4
Optimal proteome allocation for PTS and ABC transport systems.
Proteome fractions shown are fractions of the proteome available for the four specified protein groups. (A) While it is optimal for cells relying on either PTS or ABC transport systems to devote nearly all of their proteome to transport at low nutrient concentrations, for ABC transport systems, it is the proteome fraction of the binding proteins that increases as nutrient concentration decreases and not the fraction allocated to the membrane-bound transport units. (B) As the nutrient concentration decreases, the optimal maximal uptake of transport increases for PTS but remains constant for ABC transport systems. This results in an increasing ratio of optimal maximal uptake and maximal metabolic rates for transport by PTS as nutrient concentration decreases, while it is optimal for ABC transport systems to maintain this ratio closer to one.