Abstract

BELTRAN-GARCIA, Miguel J.; OROZCO, Aideé; SAMAYOA, Ivan  and  OGURA, Tetsuya. Lignin degradation products from corn stalks enhance notably the radial growth of basidiomycete mushroom mycelia. Rev. Soc. Quím. Méx [online]. 2001, vol.45, n.2, pp.77-81. ISSN 0583-7693.

Milled corn stalk (crude) was cleaned by diverse solvents (cleaned). When 1000 ppm of cleaned was added to Peptone / Glucose / Agar (PGA), the growth rate of Pleurotus ostreatus and Pleurotus sajor-caju was doubled. The mycelial diameter also increased by a supplementation of a hot water extract of cleaned corresponding to 1000 ppm, which was composed of 400 µg / g-stalk of nonvolatile compounds including 60 µg / g-stalk of phenolic monomers. An IR spectrum of the extract was very similar to that of cleaned and commercial lignin. Supplementation of crude or cleaned to Malt extract / Sucrose / Agar (MSA) promoted mycelial growth by 30 % in all five basidiomycete studied. A commercially available Kraft lignin supplemented to MSA showed cleaned-like growth promotions. The hot water extract showed growth promotion to the mycelia at a range of 10⁻⁶−10⁻⁷ M as seen in plant hormones. Therefore, we suggest these fungi use the enzymatic degradation products of lignin as a signal to faster mode of growth. This must be an important tactic of the fungi in securing their niche by degrading a vegetal biomass before competitors encroach upon it.

Keywords : Basidiomycetes; corn stalk; growth promotion; lignin-derived phenols; Pleurotus.