How (post-)genomic insights can provide new leads for improvements of mushroom cultivation

The economically important edible basidiomycete mushroom Agaricus bisporus thrives on<br/>decaying plant material in forests and grasslands of North America and Europe. It degrades forest<br/>litter and contributes to global carbon recycling, depolymerizing (hemi-)cellulose and lignin in plant<br/>biomass. Relatively little is known about how A. bisporus degrades compost in the controlled<br/>environment in commercial production facilities and utilizes this substrate to produce mushrooms.<br/>Using transcriptomics and proteomics linked to analysis of the compositional changes in the<br/>compost, we showed that changes in plant biomass degradation by A. bisporus occur throughout its<br/>life cycle. Lignin degradation appears to only occur during the spawning stage. In contrast, (hemi-<br/>)cellulolytic genes were highly expressed at the first flush, whereas low expression was observed at<br/>the second flush. The essential role for many highly expressed plant biomass degrading genes was<br/>supported by exo-proteome analysis, demonstrating the presence of these enzymes during specific<br/>stages. The out-of-phase enzyme production in the second flush may explain the reduction in the number of mushrooms during the second flush.<br/>Combined with other data generated in our lab we have now generated the first detailed model of<br/>the genes and enzymes involved in compost degradation and utilization by A. bisporus, which has<br/>provided many leads for a better understanding and improvement of the commercial mushroom<br/>cultivation.