Energetic scaling in microbial growth

Significance Understanding the principles underlying microbial growth is paramount to the cycle of carbon and nutrients in the biosphere, bioremediation technologies, and biochemical engineering, as well as to natural selection and evolution. Yet, fundamental questions remain on the links between mass and energy balances in microbial metabolism and growth. Guided by a nonequilibrium thermodynamics framework, we interpret extensive literature data on microbial growth. The analysis reveals how mass and energy conversion are tightly coupled by scaling laws relating the thermodynamic efficiency to the electron donor uptake rate and the growth yield. Most importantly, these results appear to be universal, in that they apply across microbial species and metabolic pathways, and pave the way for a general thermodynamic theory of microbiological systems.