Inducible uptake and metabolism of glucose by the phosphorylative pathway in Pseudomonas putida CSV86

Abstract

Pseudomonas putida CSV86 utilizes glucose, naphthalene, methylnaphthalene, benzyl alcohol and benzoate as the sole source of carbon and energy. Compared with glucose, cells grew faster on aromatic compounds as well as on organic acids. The organism failed to grow on gluconate, 2-ketogluconate, fructose and mannitol. Whole-cell oxygen uptake, enzyme activity and metabolic studies suggest that in strain CSV86 glucose utilization is exclusively by the intracellular phosphorylative pathway, while in Stenotrophomonas maltophilia CSV89 and P. putida KT2442 glucose is metabolized by both direct oxidative and indirect phosphorylative pathways. Cells grown on glucose showed five- to sixfold higher activity of glucose-6-phosphate dehydrogenase compared with cells grown on aromatic compounds or organic acids as the carbon source. Study of [C-14]glucose uptake by whole cells indicates that the glucose is taken up by active transport. Metabolic and transport studies clearly demonstrate that glucose metabolism is suppressed when strain CSV86 is grown on aromatic compounds or organic acids.