Carbon and sulphur utilization during growth of Pseudomonas fluorescens on potassium d-glucose 6-O-sulphate as the sole sulphur source

Abstract

Pseudomonas fluorescens N.C.I.B. 8248, cultured on potassium d-glucose 6[35S]-O-sulphate as the sole sulphur source, liberated the 6-O-sulphate ester of d-gluconate into the culture medium. Extracts of bacteria grown under this cultural condition oxidized d-glucose 6-O-sulphate to yield the gluconate ester. Results suggest the involvement of a glucose dehydrogenase-like enzyme. The gluconate ester was apparently not oxidized further to any significant extent; however, it served as substrate for a desulphating enzyme found in extracts. Growth on d-glucose 6-O-sulphate as the sole source of sulphur was not associated with the appearance of a true glycosulphatase. Collectively, these results suggest that d-gluconate 6-O-sulphate, rather than the glucose ester, supplied the necessary sulphur for growth. Oxidative activities toward d-glucose 6-O-sulphate, d-glucose, d-gluconate 6-O-sulphate and d-gluconate found in extracts of P. fluorescens adapted to grow on d-glucose 6-O-sulphate as the sole source of carbon and sulphur are presented for comparative purposes.