Industrial by-products from white-rot fungi production. Part I: Generation of enzyme preparations and chemical, protein biochemical and molecular biological characterization

Industrial by-products of white-rot fungi cultivation, in particular Lentinula edodes, Hericium erinaceus, Stropharia rugosoannulata, Fames fomentarius and Grifola frondosa, were screened in terms of composition and selected enzyme activities for potential biorecycling to produce economic profitable enzyme preparations. Spent growth substrate of Lentinula edodes cultivation was proven as natural resource rich in enzymes for conversion of lignocellulosic biomass. Subsequently, a first protocol for the recovery of lignocellulolytic enzymes was established. The chemical composition, protein profile, selected enzyme activities and hydrolyses of plant material with low digestibility were determined to study the biocatalytic potential of raw and processed by-products from Lentinula edodes cultivation. The analysis of proteome data showed diverse proteins for cellulose, hemicellulose and lignin conversion and revealed that glucanase was prevalent in comparison with identified proteins. Lignocellulolytic activities were measured at acidic (pH 4.5/30 degrees C) and neutral (pH 7.5/38 degrees C) conditions. The purification and stabilization of enzyme extract to enzyme preparation by ultrafiltration and salt/sugar application led to an increase in protein quantity and xylanase activity to a value of 35.72 mg/ml(+514%) and 133.01 U/ml (+299%). Polysaccharide degradation of hardly degradable hay and straw could be doubled in acceleration at pH and temperature optimum (pH 4/30 degrees C/24h). (C) 2016 Elsevier Ltd. All rights reserved.