Clarifying ribA-dependent survival under mild heat stress in Escherichia coli.

Zhang et al. provide an informative electrochemical framework linking riboflavin (RF) to the response of Escherichia coli to mild heat treatment (MHT). However, the central conclusion that ribA deletion abolishes survival under MHT unless exogenous RF is supplied appears difficult to reconcile with the food-matrix experiment. We highlight how RF supplementation during mutant pre-culture and post-treatment colony recovery may obscure heat-specific dependence on endogenous RF biosynthesis, and we propose a factorial validation strategy that could distinguish general riboflavin auxotrophy from a specific role in thermal adaptation.