Proteomics analysis of a long-term survival strain of Escherichia coli K-12 exhibiting a growth advantage in stationary-phase (GASP) phenotype

The aim of this work was the functional and proteomic analysis of a mutant, W3110 Bgl(+)/10, isolated from a batch culture of an Escherichia coli K-12 strain maintained at room temperature without addition of nutrients for 10 years. When the mutant was evaluated in competition experiments in co-culture with the wild-type, it exhibited the growth advantage in stationary phase (GASP) phenotype. Proteomes of the GASP mutant and its parental strain were compared by using a 2DE coupled with MS approach. Several differentially expressed proteins were detected and many of them were successful identified by mass spectrometry. Identified expression-changing proteins were grouped into three functional categories: metabolism, protein synthesis, chaperone and stress responsive proteins. Among them, the prevalence was ascribable to the metabolism group (72%) for the GASP mutant, and to chaperones and stress responsive proteins group for the parental strain (48%).