Strains degrading polysaccharides produced by bacteria from paper machines.

Biofilm-degrading enzymes are potential agents for slime control in paper machines. In this work, extracellular polysaccharides were produced by bacteria isolated from paper machines and the isolated polysaccharides were used as substrates for the screening of polysaccharide-degrading microbes. Polysaccharide yields of 1.5-3.5 g/l were obtained by ethanol precipitation from cultures of strains of Klebsiella pneumoniae, Bacillus licheniformis and Pseudomonas fluorescens on sucrose medium. Two K. pneumoniae strains apparently produced an identical heteropolysaccharide containing galacturonic acid. Fructose-containing polysaccharides were the main products of B. licheniformis and P. fluorescens. Bacteria capable of hydrolyzing the fructose-containing polymers (levans) appeared to be relatively common among the strains selected for screening. None of the bacteria or mixed cultures screened were able to utilize the Klebsiella heteropolysaccharides.