title: Encapsulation-induced stress helps Saccharomyces cerevisiae resist convertible Lignocellulose derived inhibitors.
abstract: The ability of macroencapsulated Saccharomyces cerevisiae CBS8066 to withstand readily and not readily in situ convertible lignocellulose-derived inhibitors was investigated in anaerobic batch cultivations. It was shown that encapsulation increased the tolerance against readily convertible furan aldehyde inhibitors and to dilute acid spruce hydrolysate, but not to organic acid inhibitors that cannot be metabolized anaerobically. Gene expression analysis showed that the protective effect arising from the encapsulation is evident also on the transcriptome level, as the expression of the stress-related genes YAP1, ATR1 and FLR1 was induced upon encapsulation. The transcript levels were increased due to encapsulation already in the medium without added inhibitors, indicating that the cells sensed low stress level arising from the encapsulation itself. We present a model, where the stress response is induced by nutrient limitation, that this helps the cells to cope with the increased stress added by a toxic medium, and that superficial cells in the capsules degrade convertible inhibitors, alleviating the inhibition for the cells deeper in the capsule.
authors.affiliation: School of Engineering, University of Borås, 501 90 Borås, Sweden.|Chemical and Biological Engineering-Industrial biotechnology, Chalmers University of Technology, 412 96 Göteborg, Sweden.
authors.forename: Johan O
authors.initials: JO
authors.lastname: Westman
authors.affiliation: School of Engineering, University of Borås, 501 90 Borås, Sweden.
authors.forename: Ramesh Babu
authors.initials: RB
authors.lastname: Manikondu
authors.affiliation: Chemical and Biological Engineering-Industrial biotechnology, Chalmers University of Technology, 412 96 Göteborg, Sweden.
authors.forename: Carl Johan
authors.initials: CJ
authors.lastname: Franzén
authors.affiliation: School of Engineering, University of Borås, 501 90 Borås, Sweden.
authors.forename: Mohammad J
authors.identifier: 0000-0003-4887-2433
authors.initials: MJ
authors.lastname: Taherzadeh
mesh_terms: D018914:Cells, Immobilized / Q000166:cytology / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal / Q000502:physiology*; D008031:Lignin / Q000737:chemistry / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000096:biosynthesis; D027361:Organic Anion Transporters / Q000096:biosynthesis; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000096:biosynthesis; D013312:Stress, Physiological / Q000502:physiology*; D014157:Transcription Factors / Q000096:biosynthesis
chemical_list: C108080:ATR1 protein, S cerevisiae; C118429:FLR1 protein, S cerevisiae; D026901:Membrane Transport Proteins; D027361:Organic Anion Transporters; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; C086677:YAP1 protein, S cerevisiae; C036909:lignocellulose; D008031:Lignin
keywords: HMF (5-hydroxymethyl furfural); Saccharomyces cerevisiae; biofuel; carboxylic acids; encapsulation; ethanol; furfural; inhibitors; lignocellulosic hydrolysate; q-PCR