Genetic improvement of Saccharomyces cerevisiae wine strains for enhancing cell viability after desiccation stress. Issue 8 (22nd May 2013)

• Record Type: Journal Article
• Authors: López‐Martínez, Gema; Pietrafesa, Rocchina; Romano, Patrizia; Cordero‐Otero, Ricardo; Capece, Angela; Liti, Gianni; Abbas, Charles; Kurtzman, Cletus
• Is Part Of: Yeast. Volume 30:Issue 8(2013:Aug.)
• Page Start: 319
• Page End: 330
• Publication Date: 2013-05-22
• Subjects: Yeast -- Periodicals; Yeasts -- Periodicals; Yeasts -- genetics -- Periodicals; Electronic journals; 547
• DOI: 10.1002/yea.2952
• Languages: English
• ISSNs: 0749-503X

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <p>In the last few decades spontaneous grape must fermentations have been replaced by inoculated fermentation with <italic>Saccharomyces cerevisiae</italic> strains as active dry yeast (ADY). Among the essential genes previously characterized to overcome the cell‐drying/rehydration process, six belong to the group of very hydrophilic proteins known as hydrophilins. Among them, only <italic>SIP18</italic> has shown early transcriptional response during dehydration stress. In fact, the overexpression in <italic>S</italic>. <italic>cerevisiae</italic> of gene <italic>SIP18</italic> increases cell viability after the dehydration process. The purpose of this study was to characterize dehydration stress tolerance of three wild and one commercial <italic>S</italic>. <italic>cerevisiae</italic> strains of wine origin. The four strains were submitted to transformation by insertion of the gene <italic>SIP18</italic>. Selected transformants were submitted to the cell‐drying–rehydration process and yeast viability was evaluated by both viable cell count and flow cytometry. The antioxidant capacity of SIP18p was illustrated by ROS accumulation reduction after H<sub>2</sub>O<sub>2</sub> attack. Growth data as cellular duplication times and lag times were calculated to estimate cell vitality after the cell rehydration process. The overexpressing <italic>SIP18</italic> strains showed significantly longer time of lag phase despite less time needed to stop the leakage of intracellular compounds during the rehydration process. Subsequently, the transformants were tested in inoculated grape must fermentation at laboratory scale in comparison to untransformed strains. Chemical analyses of the resultant wines indicated that no significant change for the content of secondary compounds was detected. The obtained data showed that the transformation enhances the viability of ADY without affecting fermentation efficiency and metabolic behaviour. Copyright © 2013 John Wiley & Sons, Ltd.</p> </abstract>