Differential proteomics and physiology of Pseudomonas putida KT2440 under filament-inducing conditions

Background: Pseudomonas putida exerts a filamentous phenotype in response to environmental stress conditions that are encountered during its natural life cycle. This study assessed whether P. putida filamentation could confer survival advantages. Filamentation of P. putida was induced through culturing at low shaking speed and was compared to culturing in high shaking speed conditions, after which whole proteomic analysis and stress exposure assays were performed. Results: P. putida grown in filament-inducing conditions showed increased resistance to heat and saline stressors compared to non-filamented cultures. Proteomic analysis showed a significant metabolic change and a pronounced induction of the heat shock protein IbpA and recombinase RecA in filament-inducing conditions. Our data further indicated that the associated heat shock resistance, but not filamentation, was dependent of RecA. Conclusions: This study provides insights into the altered metabolism of P. putida in filament-inducing conditions, and indicates that the formation of filaments could potentially be utilized by P. putida as a survival strategy in its hostile, recurrently changing habitat.