title: Hypoxia and iron requirements are the main drivers in transcriptional adaptation of Kluyveromyces lactis during wine aerobic fermentation.
abstract: The respiratory metabolism of yeast species alternative to Saccharomyces cerevisiae has been explored in recent years as a tool to reduce ethanol content in grape wine. The efficacy of this strategy has been previously proven for mixed cultures of non-Saccharomyces and S. cerevisiae strains. In this work, we perform a transcriptomic analysis of the Crabtree-negative yeast Kluyveromyces lactis under tightly controlled growth conditions in order to better understand physiology of non-Saccharomyces yeasts during the fermentation of grape must under aerated conditions. Transcriptional changes in K. lactis are mainly driven by oxygen limitation, iron requirement, and oxidative stress. Oxidative stress appears as a consequence of the hypoxic conditions achieved by K. lactis once oxygen supply is no longer sufficient to sustain fully respiratory metabolism. This species copes with low oxygen and iron availability by repressing iron consuming pathways and activating iron transport mechanisms. Most of the physiological and transcriptomic features of K. lactis in aerobic wine fermentation are not shared with the Crabtree-positive yeast S. cerevisiae.
authors.affiliation: Instituto de Ciencias de la Vid y del Vino (CSIC-Universidad de la Rioja-Gobierno de La Rioja), Logroño, La Rioja, Spain. Electronic address: jordi.tronchoni@icvv.es.
authors.forename: Jordi
authors.initials: J
authors.lastname: Tronchoni
authors.affiliation: Instituto de Ciencias de la Vid y del Vino (CSIC-Universidad de la Rioja-Gobierno de La Rioja), Logroño, La Rioja, Spain. Electronic address: alda.rodrigues@icvv.es.
authors.forename: Alda J
authors.initials: AJ
authors.lastname: Rodrigues
authors.affiliation: Instituto de Ciencias de la Vid y del Vino (CSIC-Universidad de la Rioja-Gobierno de La Rioja), Logroño, La Rioja, Spain. Electronic address: jantonio.curiel@icvv.es.
authors.forename: Jose Antonio
authors.initials: JA
authors.lastname: Curiel
authors.affiliation: Instituto de Ciencias de la Vid y del Vino (CSIC-Universidad de la Rioja-Gobierno de La Rioja), Logroño, La Rioja, Spain. Electronic address: pilar.morales@icvv.es.
authors.forename: Pilar
authors.initials: P
authors.lastname: Morales
authors.affiliation: Instituto de Ciencias de la Vid y del Vino (CSIC-Universidad de la Rioja-Gobierno de La Rioja), Logroño, La Rioja, Spain. Electronic address: ramon.gonzalez@icvv.es.
authors.forename: Ramon
authors.initials: R
authors.lastname: Gonzalez
mesh_terms: D000222:Adaptation, Physiological; D000332:Aerobiosis; D000431:Ethanol / Q000378:metabolism; D005285:Fermentation; D020869:Gene Expression Profiling; D007501:Iron / Q000378:metabolism*; D007716:Kluyveromyces / Q000235:genetics / Q000254:growth & development*; D018384:Oxidative Stress; D010100:Oxygen / Q000378:metabolism; D016133:Polymerase Chain Reaction; D017382:Reactive Oxygen Species / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D017423:Sequence Analysis, RNA; D014158:Transcription, Genetic; D059467:Transcriptome; D027843:Vitis / Q000378:metabolism; D014920:Wine / Q000382:microbiology*
chemical_list: D017382:Reactive Oxygen Species; D000431:Ethanol; D007501:Iron; D010100:Oxygen
keywords: Aerobic fermentation; K. lactis; Non-Saccharomyces; Oxidative stress; RNAseq