title: Influence of the propagation strategy for obtaining robust Saccharomyces cerevisiae cells that efficiently co-ferment xylose and glucose in lignocellulosic hydrolysates.
abstract: Development of xylose-fermenting yeast strains that are tolerant to the inhibitors present in lignocellulosic hydrolysates is crucial to achieve efficient bioethanol production processes. In this study, the importance of the propagation strategy for obtaining robust cells was studied. Addition of hydrolysate during propagation of the cells adapted them to the inhibitors, resulting in more tolerant cells with shorter lag phases and higher specific growth rates in minimal medium containing acetic acid and vanillin than unadapted cells. Addition of hydrolysate during propagation also resulted in cells with better fermentation capabilities. Cells propagated without hydrolysate were unable to consume xylose in wheat straw hydrolysate fermentations, whereas 40.3% and 97.7% of the xylose was consumed when 12% and 23% (v/v) hydrolysate, respectively, was added during propagation. Quantitative polymerase chain reaction revealed changes in gene expression, depending on the concentration of hydrolysate added during propagation. This study highlights the importance of using an appropriate propagation strategy for the optimum performance of yeast in fermentation of lignocellulosic hydrolysates.
authors.affiliation: Department of Biology and Biological Engineering, Industrial Biotechnology, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden.|Unit of Biotechnological Processes for Energy Production, Instituto Madrileño De Estudios Avanzados (IMDEA) Energy, 28935, Móstoles (Madrid), Spain.
authors.forename: Elia
authors.initials: E
authors.lastname: Tomás-Pejó
authors.affiliation: Department of Biology and Biological Engineering, Industrial Biotechnology, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden.
authors.forename: Lisbeth
authors.initials: L
authors.lastname: Olsson
mesh_terms: D000220:Adaptation, Biological; D003470:Culture Media / Q000737:chemistry; D004361:Drug Tolerance; D005285:Fermentation; D005947:Glucose / Q000378:metabolism*; D006131:Growth Inhibitors / Q000378:metabolism*; D008031:Lignin / Q000737:chemistry / Q000378:metabolism*; D018547:Plant Stems / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D014908:Triticum / Q000378:metabolism; D014994:Xylose / Q000378:metabolism*
chemical_list: D003470:Culture Media; D006131:Growth Inhibitors; C036909:lignocellulose; D008031:Lignin; D014994:Xylose; D005947:Glucose