Bacteriolysis by Agaricus bisporus

Summary: Agaricus bisporus, the cultivated mushroom, was able to mineralize dead 14C-labelled Bacillus subtilis and utilize the cellular components as sole source of carbon and nitrogen for growth. Consistently higher levels of bacteriolytic activity were obtained when A. bisporus was grown on lower concentrations of bacteria, 1·5 mg ml−1 as opposed to 3mg ml−1 basal liquid medium. A. bisporus also mineralized 14C-labelled bacteria in the presence of readily available alternative carbon and nitrogen sources such as glucose and ammonium sulphate. 14C-labelled bacteria were degraded to 14CO2 more efficiently than [14C]cellulose. A. bisporus was able efficiently to mineralize biomass produced in situ (>20% of total label released as 14CO2) where label was incorporated into the microbial biomass by composting rather than added as killed bacteria. This is the first time that quantitative data have been produced to show that the microbial biomass in wheat straw/animal manure compost might be significant in the nutritional strategy of basidiomycetes.