Genetic Analysis of Carbohydrate Transport-deficient Mutants of Salmonella typhimurium

Mutants ( car ) isolated from Salmonella typhimurium were unable to utilize or ferment the following carbohydrates (all d-configuration): glucose, fructose, mannose, N -acetylglucosamine, sorbitol, mannitol, maltose, melibiose, and glycerol. The mutants did utilize galactose, glucose 6-phosphate, gluconic acid, glucuronic acid, pyruvate, and l-lactate. Biochemical analysis showed that there were two classes of mutants, each lacking one component of a phosphotransferase system. CarA mutants were deficient in enzyme I; carB lacked the phosphate carrier protein, HPr. Mapping experiments showed that the carA gene was located near pro ; the carB gene mapped near purC .