<i>Ganoderma sessile</i> is a fast polysaccharide producer among <i>Ganoderma</i> species

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 <i>G. lucidum</i> and <i>G. oregonense</i> were screened for polysaccharide production and biomass yield. <i>Ganoderma</i> strains deposited as <i>G. lucidum</i> were identified as <i>G. sessile</i> and <i>G. lingzhi</i> by nuc rDNA internal transcribed spacer ITS1-5.8S-ITS2 (ITS) and translation elongation factor 1-α (<i>TEF1-α</i>) phylogenies. The identity of <i>G. oregonense</i> 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 <i>G. sessile</i> were clearly different from those of <i>G. lingzhi</i> and <i>G. oregonense</i> in both liquid culture and solid-state fermentation. The maximum polysaccharide yield (4.52 ± 0.83 g L^-1) for <i>G. sessile</i> was obtained from submerged cultures at day 9. <i>G. sessile</i> also achieved the highest linear growth in lignocellulosic solid substrates. Consequently, basidiomata were successfully obtained by solid-state fermentation in polypropylene bags, whereas <i>G. lingzhi</i> and <i>G. oregonense</i> mushrooms were not produced in artificial solid substrates. <i>G. sessile</i>, a species frequently collected in America, showed to be a promising polysaccharide producer for the manufacture of dietary supplements.