Bio-control of mycopathogens using beneficial bacteria isolated from compost and peat casing

Lecanicillium fungicola is a fungus that causes “dry bubble disease” in the commercial white button mushroom (Agaricus bisporus). This disease results in losses in yield estimated at several hundred million dollars worldwide. L. fungicola has developed resistance to the only effective fungicide (prochloraz manganese) that is approved for its control and it is expected that the use of prochloraz will soon be prohibited in the EU. The use of beneficial microbes to control plant pathogens is widely used and may be a promising method for the control of mycopathogens in mushroom production. L. fungicola was isolated from diseased mushrooms. Bacterial strains were isolated from mushroom compost (n=400) and peat casing (n=54). All bacterial strains were tested for the ability to inhibit the growth of L. fungicola using an optimised well diffusion assay.  Fifteen bacterial strains inhibited the growth of L. fungicola in vitro.  One of the bacterial strains was also effective at controlling other mushroom pathogens such as Trichoderma aggressivum, Mycogone pernicosa as well as mushroom competitor moulds such as Penicillium spp. and Aspergillus spp. using antifungal assays including well diffusion, 96 well micro titre and culture based methods.