Abstract
Fructose-bisphosphatase-deficient mutants of mucoidPseudomonas aeruginosa were isolated by ethyl methanesulfonate mutagenesis using gluconate as the nonpermissive substrate, and all the sixty isolates possessed 10–30% of the parental enzyme activity. The mutants had low levels of fructose-bisphosphate aldolase activity and could not normally synthesize alginate from any substrate except onPseudomonas isolation agar plates. The results suggest the essentiality of fructose bisphosphatase activity for the growth or survival ofP. aeruginosa and a probable linkage of genes controlling this enzyme with those of fructose bisphosphate aldolase and alginate biosynthesis.