Paper published on the relation between entropy production rate and microbial growth rate

A paper by mathematicians Maarten Droste and Bob Planqué, and VU systems biologists Maaike Remeijer and Frank Bruggeman was published in The Journal of Physical Chemistry (B). In this work, the authors study the entropy production rate, a measure for energy dissipation rate, during microbial growth. They show that for microbes that change their metabolism from an energetically efficient to a less efficient mode, the specific entropy production rate may drop as their growth rate increases. This result is counterintuitive, as the entropy production rate of a steady-state isothermal chemical reaction network rises with reaction rates. Living cells can break this relation as they can alter reaction rates by changing enzyme concentrations, giving them control over metabolic activities. As a result, the energy-inefficient mode can compensate by relying on fewer enzymes with sufficiently increased concentrations, resulting in a higher flux. This is illustrated through a case study of the yeast S. cerevisiae. The authors also derive a general criterion to predict when the specific entropy production rate drops after a metabolic shift.