Genetic and Biochemical Studies on Mannose-Negative Mutants That Are Deficient in Phosphomannose Isomerase in Escherichia coli K-12

Abstract

Two mannose-negative mutants of E. coli K-12 were isolated. These mutants are deficient in the ability to synthesize phosphomannose isomerase and capsular polysaccharide when grown on glucose-containing media. Interrupted mating experiments to determine the kinetics of genetic transfer show that the 2 mannose-negative mutations map together between the histidine and tryptophan regions of the E. coli chromosome.