In vivo evolutionary engineering for ethanol-tolerance of Saccharomyces cerevisiae haploid cells triggers diploidization

Autor: Zeynep Petek Çakar, Laurent Benbadis, Yavuz Ozturk, Arman Akşit, Abdulmecit Gokce, Tuğba Sezgin, Burcu Turanlı-Yıldız, Ceren Alkim, Jean Marie François, Ahmet Tarik Baykal
Přispěvatelé: Department of Molecular Biology & Genetics, Faculty of Science and Letters, Istanbul Technical University (ITÜ), Dr. Orhan Öcalgiray Molecular Biology, Biotechnology and Genetics Research Center (ITU-MOBGAM), Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés (LISBP), Institut National de la Recherche Agronomique (INRA)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), TÜBİTAK Research Institute for Genetic Engineering and Biotechnology, Federation of European Microbiological Societies (FEMS) Research Fellowship [2009-2], ANR-07-BLAN-0205-03, Istanbul Technical University, Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National de la Recherche Agronomique (INRA), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)
Rok vydání: 2017
Předmět:
Zdroj: Journal of Bioscience and Bioengineering
Journal of Bioscience and Bioengineering, Elsevier, 2017, 124 (3), pp.309-318. ⟨10.1016/j.jbiosc.2017.04.012⟩
Journal of Bioscience and Bioengineering, 2017, 124 (3), pp.309-318. ⟨10.1016/j.jbiosc.2017.04.012⟩
ISSN: 1389-1723
1347-4421
DOI: 10.1016/j.jbiosc.2017.04.012
Popis: Microbial ethanol production is an important alternative energy resource to replace fossil fuels, but at high level, this product is highly toxic, which hampers its efficient production. Towards increasing ethanol-tolerance of Saccharomyces cerevisiae , the so far best industrial ethanol-producer, we evaluated an in vivo evolutionary engineering strategy based on batch selection under both constant (5%, v v −1 ) and gradually increasing (5–11.4%, v v −1 ) ethanol concentrations. Selection under increasing ethanol levels yielded evolved clones that could tolerate up to 12% (v v −1 ) ethanol and had cross-resistance to other stresses. Quite surprisingly, diploidization of the yeast population took place already at 7% (v v −1 ) ethanol level during evolutionary engineering, and this event was abolished by the loss of MKT1 , a gene previously identified as being implicated in ethanol tolerance (Swinnen et al., Genome Res., 22, 975–984, 2012). Transcriptomic analysis confirmed diploidization of the evolved clones with strong down-regulation in mating process, and in several haploid-specific genes. We selected two clones exhibiting the highest viability on 12% ethanol, and found productivity and titer of ethanol significantly higher than those of the reference strain under aerated fed-batch cultivation conditions. This higher fermentation performance could be related with a higher abundance of glycolytic and ribosomal proteins and with a relatively lower respiratory capacity of the evolved strain, as revealed by a comparative transcriptomic and proteomic analysis between the evolved and the reference strains. Altogether, these results emphasize the efficiency of the in vivo evolutionary engineering strategy for improving ethanol tolerance, and the link between ethanol tolerance and diploidization.
Databáze: OpenAIRE
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