CHEMICALLY-DEFINED SOLID-STATE FERMENTATION OF PLEUROTUS-OSTREATUS

Pleurotus ostreatus, a white-rot edible mushroom, was cultivated on pe rlite particles supplemented stalks. Extracellular proteins were extra cted and fungal biomass was measured directly. Concomitant vigorous gr owth of P. ostreatus aerial hyphae was observed with glucose utilizati on. Uniform growth over the solid particle surface resulted in small v ariances in both mineralization rates of radiolabeled glucose and lign in and physiological parameters. Totals of 60% and 40% of the [C-14]gl ucose were mineralized during solid-state fermentation on perlite-defi ned medium and cotton stalks, respectively. A higher mineralization of [C-14]lignin was also observed during fermentation on perlite-defined medium vs. that on natural substrate (cotton stalks). The presence of CO2 in the headspace was found to be essential for P. ostreatus growt h. A modified biometer flask was therefore developed to periodically t rap the (CO2)-C-14 released by mineralization of [C-14]substances.