Polysaccharide Depolymerase Associated with Bacteriophage Infection

Abstract

Bartell, Pasquale F. (University of Pennsylvania, Philadelphia), Thomas E. Orr, and Grace K. H. Lam . Polysaccharide depolymerase associated with bacteriophage infection. J. Bacteriol. 92: 56–62. 1966.—A recently isolated bacteriophage of Pseudomonas aeruginosa was observed, in association with bacteria, to produce a polysaccharide depolymerase. Exposure of slime polysaccharide to the enzyme at the p H optimum of 7.5 for 30 to 60 min resulted in a decreased viscosity of 20 to 25%, and a measurable increase in the levels of hexosamines, hexoses, and reducing substances, distinguishing it from other phage-associated depolymerases. Like egg-white lysozyme, the depolymerase produced a clearing of mature bacterial lawns, but was shown to be devoid of muralytic activity by turbidimetric and paper chromatographic analysis. The depolymerase reacted with polysaccharides of only certain strains of P. aeruginosa , and there appeared to be no correlation with phage susceptibility. The enzyme was not detectable in uninfected cultures, nor was it synthesized when infection was initiated by phages other than phage 2. The available data suggest that the genetic information required for biosynthesis of this enzyme is furnished by the phage 2 genome.