Print Email Facebook Twitter Engineering the thermotolerant industrial yeast Kluyveromyces marxianus for anaerobic growth Title Engineering the thermotolerant industrial yeast Kluyveromyces marxianus for anaerobic growth Author Dekker, W.J.C. (TU Delft BT/Industriele Microbiologie) Ortiz Merino, R.A. (TU Delft BT/Industriele Microbiologie) Kaljouw, Astrid (Student TU Delft) Battjes, Julius (Student TU Delft) Wiering, Frank W. (Student TU Delft) Mooiman, C. (TU Delft BT/Bioprocess Engineering) de la Torre, P. (TU Delft BT/Industriele Microbiologie) Pronk, J.T. (TU Delft BT/Biotechnologie) Department BT/Biotechnologie Date 2021 Abstract Current large-scale, anaerobic industrial processes for ethanol production from renewable carbohydrates predominantly rely on the mesophilic yeast Saccharomyces cerevisiae. Use of thermotolerant, facultatively fermentative yeasts such as Kluyveromyces marxianus could confer significant economic benefits. However, in contrast to S. cerevisiae, these yeasts cannot grow in the absence of oxygen. Responses of K. marxianus and S. cerevisiae to different oxygen-limitation regimes were analyzed in chemostats. Genome and transcriptome analysis, physiological responses to sterol supplementation and sterol-uptake measurements identified absence of a functional sterol-uptake mechanism as a key factor underlying the oxygen requirement of K. marxianus. Heterologous expression of a squalene-tetrahymanol cyclase enabled oxygen-independent synthesis of the sterol surrogate tetrahymanol in K. marxianus. After a brief adaptation under oxygen-limited conditions, tetrahymanol-expressing K. marxianus strains grew anaerobically on glucose at temperatures of up to 45 °C. These results open up new directions in the development of thermotolerant yeast strains for anaerobic industrial applications. Subject Anaerobic metabolismErgosterolEthanol productionMetabolic engineeringTetrahymanolThermotoleranceYeast biotechnology To reference this document use: http://resolver.tudelft.nl/uuid:b4cb7f7d-0c4f-40ba-944c-a4fe9e2d47cc DOI https://doi.org/10.1016/j.ymben.2021.07.006 ISSN 1096-7176 Source Metabolic Engineering, 67, 347-364 Part of collection Institutional Repository Document type journal article Rights © 2021 W.J.C. Dekker, R.A. Ortiz Merino, Astrid Kaljouw, Julius Battjes, Frank W. Wiering, C. Mooiman, P. de la Torre, J.T. Pronk Files PDF 1_s2.0_S1096717621001166_main.pdf 9.77 MB Close viewer /islandora/object/uuid:b4cb7f7d-0c4f-40ba-944c-a4fe9e2d47cc/datastream/OBJ/view