Whereas Escherichia coli does not naturally produce the 1-propanol unless subjected to extensive genetic modifications, we show that this important industrial commodity is produced in hypoxic conditions inside biofilms. 1-propanol production corresponds to a native threonine fermentation pathway previously undocumented in E. coli and other Enterobacteriaceae. This widespread adaptive response contributes to maintain cellular redox balance and bacterial fitness in biofilms and other amino acid-rich hypoxic environments. This study therefore shows that mining complex lifestyles such as biofilm microenvironments provides new insight into the extent of bacterial metabolic potential and adaptive bacterial physiological responses.
• Létoffé S, Chalabaev S, Dugay J, Stressmann F, Audrain B, Portais JC, Letisse F, Ghigo JM.(2017). Biofilm microenvironment induces a widespread adaptive amino-acid fermentation pathway conferring strong fitness advantage in Escherichia coli. PLoS Genet. 2017 May 19;13(5)