Physiological control of alkylsulfatase synthesis in Pseudomonas aeruginosa: effects of glucose, glucose analogs, and sulfur

Abstract

Pseudomonas aeruginosa (isolated from soil) synthesizes an alkylsulfatase allowing this bacterium to utilize sodium hexan-1-yl sulfate as a source of carbon and sulfur for growth. The formation of the enzyme was induced by this and by other (C4–C16) primary alkylsulfate esters as well as by some (C-8 and C-9) primary alkylsulfonates. Secondary (2-yl) alkylsulfate esters did not act as inducers. The induction of alkylsulfatase was markedly inhibited by L-cysteine, L-methionine, sodium sulfide, and by high (>2 mM) concentrations of D-glucose and other related monosaccharides. Similar inhibitory effects by four glucose analogs which will not support growth suggest that prior metabolism was not a requirement for glucose-mediated inhibition. The inhibition by D-glucose of the same inducible system in P. aeruginosa (PAO-57) supported this conclusion since this glucose transport-positive mutant is deficient in the further metabolism of the monosaccharide. At low (0.1–1.0 mM) concentrations, D-glucose or D-glucose 6-O-phosphate (20 mM) caused a marked enhancement of alkylsulfatase induction in the isolate. This novel enhancement was reproduced using P. aeruginosa strain PAO. However, both monosaccharides acted as potent inhibitors of alkylsulfatase formation occurring in mutant PAO-57 which, unlike the parent strain PAO, exhibits low glucose-6-phosphate dehydrogenase activity. These results suggest that D-glucose (0.1–1.0 mM) must be metabolized to enhance the synthesis of the enzyme.