Fermentative capacity ofKluyveromyces marxianusandSaccharomyces cerevisiaeafter oxidative stress

Abstract

Volatile compound production during alcoholic fermentation has been studied in the production of many beverages. Temperature, yeast strain, nutrients and pH have been identified as important factors in the production of volatile compounds. In addition, other factors could influence this production during the fermentation process as well. Oxidative stress could occur during yeast biomass production because oxygen is an essential nutrient that is added to the growth medium. The fermentation parameters and the volatile compound production of one Saccharomyces cerevisiae strain (MC4) and two Kluyveromyces marxianus strains (OFF1 and SLP1) were evaluated in relation to fermentation parameters after oxidative stress induced by hydrogen peroxide or menadione. These yeasts were compared with S. cerevisiae W303–1A and showed significant differences in ethanol production, ethanol yield and maximum ethanol production rate. K. marxianus (OFF1) showed better fermentative capacity after oxidative stress. The higher alcohol production decreased after oxidative stress by >35% after 72 h fermentation time, and the amyl alcohol decreased at a higher level (>60%); however, the isobutanol production increased after oxidative stress between 1.5 and 4 times. The yeasts produced significant concentrations of esters however ethyl lactate, ethyl caprylate and the ethyl caproate were not detected in the control fermentation, while in the stress fermentation they accounted for up to 3 mg/L. These results demonstrate that oxidative stress can play an important role in the final aroma profile; but it is necessary to guarantee adequate yeast growth to obtain the volatile compounds desired. Copyright © 2017 The Institute of Brewing & Distilling

Detection of spoilage-causing yeasts and bacteria in tchapalo, the Ivorian traditional sorghum beer

“…The strong contribution of these species in the modification of the sensory profile of tchapalo is not surprising since several authors have reported that these yeasts can produce metabolites capable of having an impact on the aromatic profile of alcoholic beverages (Magyar and Toth 2011; Arellano‐Plaza et al . 2017). For tchapalo inoculated with AAB strains (G4), only the taste was noted as spoiled (80% of the panellists) with A. cerevisiae whereas with A. pasteurianus the taste and odour were spoiled.…”

Fluorescence lifetime imaging of NAD(P)H upon oxidative stress in Kluyveromyces marxianus

“…High temperature and H 2 O 2 induced oxidative stress in K. marxianus (Arellano-Plaza et al, 2017;Fu et al, 2019). Increased…”

Preservation of non‐Saccharomyces yeasts: Current technologies and challenges

“…It is possible to activate the antioxidant system by adding non‐lethal concentrations of stressors such as H 2 O 2 for short periods, before the application of the biocontrol yeast Y. lipolytica , allowing the antioxidant system to be activated, increasing its cell viability (Liu et al., 2011). Even adding stressful compounds to K. marxianus before fermentation not only increases their antioxidant processes, but also activates the production of important volatile compounds in the production of fermented beverages (Arellano‐Plaza et al., 2017). It has been observed that non‐ Saccharomyces yeasts may have a higher resistance to oxidative stress, such as K. marxianus , which has a different respiratory capacity than S. cerevisiae , showing greater long‐term viability (Arellano‐Plaza et al., 2013).…”

“…Yeasts response to oxidative stress S. cerevisiae response to oxidative stress has been studied under different environments, including growth conditions, physiological conditions in which endogenous metabolism and its transitions cause harmful changes in the redox state (Gibson et al, 2008), and the addition of oxidizing compounds such as H 2 O 2 and menadione (Arellano-Plaza et al, 2017). During oxidative stress in S. cerevisiae, general transcriptional factors such as Msn2p/Msn4p, Yap1p, and Skn7p are activated, which help reprogramming gene expression in response to oxidative injury.…”