title: Cellulase stability, adsorption/desorption profiles and recycling during successive cycles of hydrolysis and fermentation of wheat straw.
abstract: The potential of enzymes recycling after hydrolysis and fermentation of wheat straw under a variety of conditions was investigated, monitoring the activity of the enzymes in the solid and liquid fractions, using low molecular weight substrates. A significant amount of active enzymes could be recovered by recycling the liquid phase. In the early stage of the process, enzyme adsorb to the substrate, then gradually returning to the solution as the saccharification proceeds. At 50°C, normally regarded as an acceptable operational temperature for saccharification, the enzymes (Celluclast) significantly undergo thermal deactivation. The hydrolysis yield and enzyme recycling efficiency in consecutive recycling rounds can be increased by using high enzyme loadings and moderate temperatures. Indeed, the amount of enzymes in the liquid phase increased with its thermostability and hydrolytic efficiency. This study contributes towards developing effective enzymes recycling strategies and helping to reduce the enzyme costs on bioethanol production.
authors: Centro de Engenharia Biológica, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal. Electronic address: ana_cris@deb.uminho.pt.
authors: Ana Cristina
authors: AC
authors: Rodrigues
authors: Department of Geosciences and Natural Resource Management, University of Copenhagen, Rolighedsvej 23, DK-1958 Frederiksberg C, Denmark. Electronic address: cf@life.ku.dk.
authors: Claus
authors: C
authors: Felby
authors: Centro de Engenharia Biológica, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal. Electronic address: fmgama@deb.uminho.pt.
authors: Miguel
authors: M
authors: Gama
mesh_terms: D002480:Cellulase / Q000378:metabolism*; D005591:Chemical Fractionation; D004795:Enzyme Stability; D005285:Fermentation; D006868:Hydrolysis; D008031:Lignin / Q000378:metabolism; D059027:Recycling; D013997:Time Factors; D014908:Triticum / Q000737:chemistry*; D014866:Waste Products; D001617:beta-Glucosidase / Q000378:metabolism
chemical_list: D014866:Waste Products; C036909:lignocellulose; D008031:Lignin; D001617:beta-Glucosidase; D002480:Cellulase
keywords: Adsorption/desorption; Cellulase; Recycling; Thermo-stability