title: Spent mushroom substrate of Pleurotus pulmonarius: a source of easily hydrolyzable lignocellulose.
abstract: Pleurotus pulmonarius was cultivated on a corncob-based substrate for producing of mushrooms and for assessing the transformation of the lignocellulosics during the development of fungal biomass. Associated events, such as the release of relevant enzymes and the H2O2 generation, were also monitored. The peaks of laccase and catalase activities occurred at the 5th day and that of Mn peroxidase at the 30th day, simultaneously with a high activity of superoxide dismutase. Increase in the endocellulase and xylanase activities was observed after 10 days, with maximal activities achieved during the 20-30-day period. Maximal values of H2O2 were found after 10 days of cultivation. Electron microscopy and Fourier transform infrared (FTIR) spectroscopy showed strong alterations in the lignocellulosic fibers. The uncultivated and the cultivated substrates at different times were hydrolyzed with commercial cellulase and β-glucosidase. The highest values of reducing sugars (110.5 ± 5.6 μmol/mL), being 65 % glucose, were obtained using the 20-day cultivated substrate. After the fruiting stage (first flush), enzymatic hydrolysis of the spent mushroom substrate (SMS) yielded 53.0 ± 2.8 and 77.5 ± 4.0 μmol/mL of glucose and total reducing sugars, respectively. Although the release of reducing sugars of the P. pulmonarius SMS was lower than that obtained after 20 days of cultivation, it was still 50 % higher than that obtained using the uncultured substrate. This observation, combined with the fact that SMS constitutes a residue generated as a by-product of the depletion of an agro-industrial residue, allows to conclude that this material offers an interesting economic perspective for the obtainment of cellulosic ethanol.
authors.affiliation: Postgraduate Program of Food Science, State University of Maringá, 87020-900, Maringá, PR, Brazil.
authors.forename: Rúbia Carvalho Gomes
authors.initials: RC
authors.lastname: Corrêa
authors.affiliation: Department of Biochemistry, State University of Maringá, 87020-900, Maringá, PR, Brazil.
authors.forename: Bruna Polacchini
authors.initials: BP
authors.lastname: da Silva
authors.affiliation: Department of Biochemistry, State University of Maringá, 87020-900, Maringá, PR, Brazil.
authors.forename: Rafael
authors.initials: R
authors.lastname: Castoldi
authors.affiliation: Postgraduate Program of Food Science, State University of Maringá, 87020-900, Maringá, PR, Brazil.
authors.forename: Camila Gabriel
authors.initials: CG
authors.lastname: Kato
authors.affiliation: Postgraduate Program of Food Science, State University of Maringá, 87020-900, Maringá, PR, Brazil.|Department of Biochemistry, State University of Maringá, 87020-900, Maringá, PR, Brazil.
authors.forename: Anacharis Babeto
authors.initials: AB
authors.lastname: de Sá-Nakanishi
authors.affiliation: Department of Chemistry, Federal University of Santa Catarina, Florianópolis, Brazil.
authors.forename: Rosely Aparecida
authors.initials: RA
authors.lastname: Peralta
authors.affiliation: Department of Biochemistry, State University of Maringá, 87020-900, Maringá, PR, Brazil.
authors.forename: Cristina G M
authors.initials: CG
authors.lastname: de Souza
authors.affiliation: Postgraduate Program of Food Science, State University of Maringá, 87020-900, Maringá, PR, Brazil.|Department of Biochemistry, State University of Maringá, 87020-900, Maringá, PR, Brazil.
authors.forename: Adelar
authors.initials: A
authors.lastname: Bracht
authors.affiliation: Postgraduate Program of Food Science, State University of Maringá, 87020-900, Maringá, PR, Brazil. rosanemperalta@gmail.com.|Department of Biochemistry, State University of Maringá, 87020-900, Maringá, PR, Brazil. rosanemperalta@gmail.com.
authors.forename: Rosane Marina
authors.initials: RM
authors.lastname: Peralta
mesh_terms: D004798:Enzymes / Q000032:analysis; D006861:Hydrogen Peroxide / Q000032:analysis; D008031:Lignin / Q000032:analysis*; D008854:Microscopy, Electron; D020076:Pleurotus / Q000254:growth & development* / Q000378:metabolism*; D017550:Spectroscopy, Fourier Transform Infrared; D003313:Zea mays / Q000737:chemistry* / Q000382:microbiology* / Q000648:ultrastructure
chemical_list: D004798:Enzymes; C036909:lignocellulose; D008031:Lignin; D006861:Hydrogen Peroxide