Microbial redox cycling enhances ecosystem thermodynamic efficiency and
productivity
Abstract
Microbial life in an ecosystem with low energy supply has been
considered to employ two energy utilization strategies. The first is
energy conservation at an individual level, while the second is energy
use optimization in response to the availability of energy resources.
Here, using an oxidation-reduction (redox) reaction network model where
microbial metabolic pathways are established through multiple
species-level competition and cooperation within a redox reaction
network, we hypothesize that microbial ecosystems can move forward to
increase energy use efficiency, namely an energy efficiency strategy at
the community level. This strategy is supported by microbial functional
diversity that enables species to interact with others in various ways
of metabolic handoffs. Moreover, the high energy use efficiency is
attributable to the mutualistic division of labor that increases the
complexity of metabolic pathways, which actively drives material cycling
to exploit more energy.