Breeding of a 5-Fluorouridine-resistant Mutant with Increased Cellulose Production fromAcetobacter xylinumsubsp.nonacetoxidans

Abstract

UDP-glucose (UDP-G), the direct precursor ef cellulose, is known to be produced from UTP and glllcose-1-phosphate. In all attempt to increase UTP biosynthesis, 5fiuorouridine (5-FUR: a pyrimidine analog)-resistant mutants were obtained using Acetobacter rylinum subsp. nonacetoxidans 757 as the parent strain. One of the 5-FUR-resistant mutants, FUR･35, showed about 40% higher cellulose productivien compared to the parent strain. Intracelluiar levels of UTP and UDP-G in FUR-35 was follnd to be higher than those in the parent strain. The carbamyl phosphate synthetase II (CPS) actiyity of FUR-35 was higher than that of the parent straill and the feedback inhibition of CPS by UTP in FUR-35 had been released compared with that in the parent strain. These results suggest that the increased cellulose production of FUR-35 was attributable to its higher of intracellular UDP-G level resultillg frem increEsed UTP biesynthesis.