HEXOSE PHOSPHATE-METABOLISM AND EXOPOLYSACCHARIDE FORMATION IN PSEUDOMONAS-CEPACIA

When grown on solid medium containing excess glucose, glucose dehydrogenase-deficient (Gcd-) mutants of Pseudomonas cepacia 249 formed large amounts of an exopolysaccharide comprised of galactose, glucose, mannose, glucuronic acid, and rhamnose. The Gcd+ parent strain failed to accumulate comparable amounts of exopolymer from glucose because of its rapid conversion of glucose to gluconic and 2-ketogluconic acids and its lower content of enzymes related to glucose-1-phosphate synthesis. Both Gcd+ and Gcd- strains of P. cepacia accumulated exopolymer when substrates such as mannitol and glycerol were substituted for glucose. A survey of clinical isolates from patients with cystic fibrosis indicated that there was no correlation between ability of P. cepacia to colonize the respiratory tracts of such individuals and increased capacity to form exopolymer related to glucose dehydrogenase deficiency. © 1990 Springer-Verlag New York Inc.