Transport and metabolism of trehalose in Escherichia coli and Salmonella typhimurium.

The metabolism of trehalose in wild type cells of Escherichia coli and Salmonella typhimurium has been investigated. Intact cells of Escherichia coli (grown on trehalose) accumulated [14C]-trehalose as [14C]-trehalose 6-phosphate. Toluene-treated cells catalyzed the synthesis of the [14C]-sugar phosphate from [14C]-trehalose and phosphoenolpyruvate; ATP did not serve as phosphoryl donor. Trehalose 6-phosphate could subsequently be hydrolyzed by trehalose 6-phosphate hydrolase, an enzyme which catalyzes the hydrolysis of the disaccharide phosphate into glucose and glucose 6-phosphate. Both Escherichia coli and Salmonella typhimurium induced this enzyme when they grew on trehalose. These findings suggest that trehalose is transported in these bacteria by an inducible phosphoenolpyruvate:trehalose phosphotransferase system. The presence of a constitutive trehalase was also detected.