Functional integrity and structural stability of freeze-dried ectomycorrhizal fungi established through viability assays

Lyophilized vegetative mycelium of ectomycorrhizal fungi was subjected to various viability tests to confirm functional integrity. Physical integrity of freeze-dried cultures was comparable to that of non-lyophilized cultures. Inter- and intraspecific variations in morphology, physiology, and metabolic rate were maintained after lyophilization. Maintenance of total protein content confirmed metabolic stability. According to the assays of viability, a plating assay and determination of total biomass confirmed stable mitotic activity of the freeze-dried cultures.