Evaluating the growth and enzyme production from Lentinula edodes strains

Abstract

Growth and enzymic activities of nine strains of the mushroom shiitake, Lentinula edodes (Berk. Pegler) cultivated on eucalyptus residues constituted by ground barks, branches and leaves were evaluated. Isolates of L. edodes strains were cultivated on medium composed of eucalyptus residue and rice bran (80:20) mixed in a 125 ml Erlenmeyer flask at 26 °C for 30 days. This residue proved to be a suitable material for mycelial growth and yielded 1.4–20.2 mg mycelium per g residue. Xylanase activity was about 15,000 U kg −1 and cellulase was 10 times lower, however, the activities of β-glucosidase and β-xylosidase were very similar. Mn-peroxidase was detected in all stains, whereas the activity of laccase fluctuated significantly within species. The type of L. edodes strain has a considerable effect both on substrate colonization and on the type of hydrolytic and oxidative enzymes produced and these characteristics may be useful for mushroom growing. The correlation observed between fungal growth and enzyme production may be a good parameter to evaluate the period between inoculation of the substrate and fructification. Thus, the facilities for determination of enzyme activities may replace the laborious methodologies for quantification of the growth of fungi in solid substrates.