Effect of cereal brans on Lentinula edodes growth and enzyme activities during cultivation on forestry waste

Abstract

To develop strategies for increasing the growth of Lentinula edodes in eucalyptus residues. To this end, we have examined the effects of cereal brans additions on production of mycelial biomass and enzymes. Three isolates of the mushroom shiitake, L. edodes (Berk. Pegler), were evaluated for enzyme and ergosterol production on eucalyptus residue supplemented with 5, 10, 15 and 20% (w/w) of soya, wheat or rice brans. Nitrogen imput on eucalyptus residues accelerated mycelial growth by supplying the L. edodes with this limiting nutrient. High levels of enzymes activities were produced in eucalyptus residues supplemented by soya bran. Comparison of cellulose and xylanase production with manganese peroxidase (MnP) at 20% soya bran indicated that hydrolytic enzymes, but oxidative enzymes were reduced. Mycelial growth measurements revealed that eucalyptus residues supplemented with cereal brans supported fast growth of L. edodes, indicating that mycelium extension is related to the bioavailability of nitrogen. The type and concentration of nutrient supplement has a considerable effect both on substrate colonization and on the type of hydrolytic and oxidative enzymes produced. These characteristics may be useful for mushroom growing. Lentinula edodes is commercially important for edible mushroom production and supplements which enhance growth and enzymes production might also be beneficial for mushroom yields.