Biosynthesis of exopolysaccharide by Pseudomonas aeruginosa

Abstract

In batch cultures of P. aeruginosa, the maximum rate of exopolysaccharide synthesis occurred during exponential growth. In nitrogen-limited continuous culture, the specific rate of exopolysaccharide synthesis increased from 0.27 g g of cell-1 hr-1 at a dilution rate (D) of 0.05 hr-1 to 0.44 g g of cells hr-1at D = 0.1 hr-1. The yield of exopolysaccharide on the basis of glucose used was in the range of 56 to 64%. Exopolysaccharide was also synthesized in carbon-limited cultures at 0.19 g g of cell-1 hr-1 at D = 0.05 hr-1 in a 33% yield. Nonmucoid variants appeared after seven generations in continuous culture and rapidly increased in proportion to the total number of organisms present.