Ecology, Phylogeny, and Potential Nutritional and Medicinal Value of a Rare White “Maitake” Collected in a Mediterranean Forest

Albino Grifola frondosa (Dicks.) Gray “maitake” mushrooms (described as G. albicansImazeki and then placed in synonymy with G. frondosa) are particularly rare, and the few pertinentrecords are not treated in scientific publications. A field investigation carried out in Sicily (Italy) ledto the collection of an unusual white Grifola specimen at the base of a living tree of Quercus pubescensWilld. s.l. The outcome of sequencing the internal transcribed spacer (ITS) region of nuclearribosomal DNA (nrDNA) indicated that it belongs to G. frondosa and provided an insight to thephylogenetic relationships within the genus. The results of nutritional composition analysis showedthat the albino basidioma possesses relatively high contents of Ca, Fe, K, and Cu and is rather lowin Na when compared with literature data on edible mushrooms. Vitamin (B1, B2, B3, B5, B9, and D2)contents ranged from 0.15 to 3.89 mg per 100 g of mushroom dry weight. The cold‐water extract ofthis specimen was effective at inhibiting the growth of Staphylococcus epidermidis ATCC 12228 andPseudomonas aeruginosa ATCC 15442 at the maximum screening concentration of 50% v/v. Inaddition, the extract slowed down the ability of Staphylococcus aureus ATCC 43300 to form biofilms.According to data hereby reported, the albino G. frondosa is a culinary‐medicinal mushroom with apromising exploitation potential.