Plant Pathology Department


Date of this Version

April 1985


Published in APPLIED AND ENVIRONMENTAL MICROBIOLOGY, Apr. 1985, p. 994-996 Vol. 49, No. 4. Copyright © 1985, American Society for Microbiology. Used by permission.


Erwinia amylovora infected with bacteriophage ERA103 produced an enzyme which degraded the extracellular polysaccharide of noninfected cells. The depolymerase enzyme was purified 15-fold by a procedure which included ammonium sulfate precipitation, ultracentrifugation, CM-Sephadex batchwise separation, Sephadex G-50 column chromatography, and Sephacryl S-200 column chromatography. The enzyme had a molecular weight of approximately 21,000 and a pH optimum of 6.0. Activity was enhanced by supplements of 2-mercaptoethanol or dithiothreitol.