title: Kinetic modeling of multi-feed simultaneous saccharification and co-fermentation of pretreated birch to ethanol.
abstract: Fed-batch simultaneous saccharification and fermentation (SSF) is a feasible option for bioethanol production from lignocellulosic raw materials at high substrate concentrations. In this work, a segregated kinetic model was developed for simulation of fed-batch simultaneous saccharification and co-fermentation (SSCF) of steam-pretreated birch, using substrate, enzymes and cell feeds. The model takes into account the dynamics of the cellulase-cellulose system and the cell population during SSCF, and the effects of pre-cultivation of yeast cells on fermentation performance. The model was cross-validated against experiments using different feed schemes. It could predict fermentation performance and explain observed differences between measured total yeast cells and dividing cells very well. The reproducibility of the experiments and the cell viability were significantly better in fed-batch than in batch SSCF at 15% and 20% total WIS contents. The model can be used for simulation of fed-batch SSCF and optimization of feed profiles.
authors.affiliation: Chalmers University of Technology, Department of Chemical and Biological Engineering, Division of Life Sciences - Industrial Biotechnology, SE-412 96 Göteborg, Sweden.
authors.forename: Ruifei
authors.initials: R
authors.lastname: Wang
authors.affiliation: Chalmers University of Technology, Department of Chemical and Biological Engineering, Division of Life Sciences - Industrial Biotechnology, SE-412 96 Göteborg, Sweden.
authors.forename: Rakesh
authors.initials: R
authors.lastname: Koppram
authors.affiliation: Chalmers University of Technology, Department of Chemical and Biological Engineering, Division of Life Sciences - Industrial Biotechnology, SE-412 96 Göteborg, Sweden.
authors.forename: Lisbeth
authors.initials: L
authors.lastname: Olsson
authors.affiliation: Chalmers University of Technology, Department of Chemical and Biological Engineering, Division of Life Sciences - Industrial Biotechnology, SE-412 96 Göteborg, Sweden. Electronic address: franzen@chalmers.se.
authors.forename: Carl Johan
authors.initials: CJ
authors.lastname: Franzén
mesh_terms: D029662:Betula / Q000737:chemistry* / Q000382:microbiology*; D019149:Bioreactors / Q000382:microbiology*; D002482:Cellulose / Q000737:chemistry*; D003198:Computer Simulation; D000431:Ethanol / Q000378:metabolism*; D007700:Kinetics; D008657:Metabolic Clearance Rate; D008954:Models, Biological; D008956:Models, Chemical; D012441:Saccharomyces cerevisiae / Q000502:physiology*
chemical_list: D000431:Ethanol; D002482:Cellulose
keywords: 2nd generation biofuel; Enzymatic hydrolysis; Fed-batch saccharification and co-fermentation; S. cerevisiae; Segregated cell model