Several pseudomonads, associated with the cultivated mushrooms Agaricus bisporus or Pleurotus sp., are hemolytic

Pseudomonas tolaasii, causing brown blotch disease on cultivated mushrooms, and yielding a white line precipitate towards P reactans, has been shown to induce lysis of erythrocytes. Some Finnish strains isolated from diseased mushroom fruit bodies, although harboring the typical features of R tolaasii, proved to be distinct, and have been allocated to a nov. sp. R costantinii. We examined in these study whether all brown blotch causing agents were hemolytic. The induction of erythrocytes lysis seemed to be a rather common feature of mushroom associated-pseudomonads, especially for strains involved in the production of a white-line-in agar.