Growth rate-specific physiology
In bacteria, reduced growth rates induce broad resistance to various environmental stresses . Similarly, our study showed that besides specific metabolic responses to carbon limitation, low growth rates triggered a general stress response in G. metallireducens. This was reflected by increased abundances of enzymes related to the utilization of alternative electron acceptors, signal transduction and protection against oxidative stress (Fig. 5). In G. sulfurreducens , some of these homologous proteins were also found to belong to the regulon of sigma RpoS, a master regulator of the general stress response . Such physiology is advantageous for Geobactereaceae to survive in natural habitats with energy limitation, heavy metals, or oxidative stress.