Ganoderma sessile is a fast polysaccharide producer among Ganoderma species

Abstract

ABSTRACT The selection of fast-growing and high-yield-producing strains is required to satisfy the market demand on fungal food supplements. To that aim, three strains deposited in our collection as G. lucidum and G. oregonense were screened for polysaccharide production and biomass yield. Ganoderma strains deposited as G. lucidum were identified as G. sessile and G. lingzhi by nuc rDNA internal transcribed spacer ITS1-5.8S-ITS2 (ITS) and translation elongation factor 1-α (TEF1-α) phylogenies. The identity of G. oregonense was confirmed by molecular phylogeny and biogeography. Additionally, mycelial antagonism confirmed species differentiation, and strains were further distinguished by morphology and protein profiles. Biomass and polysaccharide yields of G. sessile were clearly different from those of G. lingzhi and G. oregonense in both liquid culture and solid-state fermentation. The maximum polysaccharide yield (4.52 ± 0.83 g L−1) for G. sessile was obtained from submerged cultures at day 9. G. sessile also achieved the highest linear growth in lignocellulosic solid substrates. Consequently, basidiomata were successfully obtained by solid-state fermentation in polypropylene bags, whereas G. lingzhi and G. oregonense mushrooms were not produced in artificial solid substrates. G. sessile, a species frequently collected in America, showed to be a promising polysaccharide producer for the manufacture of dietary supplements.