Bacterial blotch disease of the cultivated mushroom Agaricus bisporus: screening, isolation and characterization of bacteria antagonistic to the pathogen (Pseudomonas tolaasii)

Abstract

Bacteria, mainly pseudomonads, were isolated from mushroom farms and from soil and plant materials. They were screened for antagonism to Pseudomonas tolaasii, the cause of bacterial blotch of mushroom, using an exclusion zone assay against a bacterial lawn of the pathogen. Selected potential antagonists were identified by the API system and whole cell fatty acid profiles. These strains were tested further in the white line test and host pathogenicity test with mushroom caps. Some of the antagonists have been stable in their aggressiveness over 1 year and several transfers during storage on nutrient agar.