As regards the growth factor requirements of fungi in general. Most higher fungi need
thiamine as growth factor. In addition, some species
need adenine (Fomes officinalis and Poria vaillanti), biotin and riboflavine
(Porta vaillanti) or pyridoxine (an unidentified psychrophiUc basidiomycete).
Only a few species {Morchella conica, Ptychogaster rubescens,
Trametes serialis) have been reported to be prototrophic. The
growth of Boletus variegatus and Collybia velutipes can be stimulated by
fructose-1,6-diphosphate