ppk (PP_5217) encodes the main polyphosphate kinase of P. putida KT2440; its deletion reduces intracellular polyP by ~70-90% and impairs stationary-phase survival, motility, biofilm formation, RpoS expression, and tolerance to UV, antibiotics, metals, solvents and heat.
"Accumulation of inorganic polyphosphate enables stress endurance and catalytic vigour in Pseudomonas putida KT2440."