Influences of acid and ethanol stresses on Oenococcus oeni SD‐2a and its proteomic and transcriptional responses

• Published in: Journal of the science of food and agriculture Vol. 101; no. 7; pp. 2892 - 2900
• Main Authors: Yang, Kun, Dai, Xianjun, Fan, Mingtao, Zhang, Guoqiang
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.05.2021; John Wiley and Sons, Limited
• Subjects: Acids; Acids - metabolism; Adenosine triphosphate; ATP; Bacterial Proteins - chemistry; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Cell membranes; comparative proteomics; cross‐protection; Depolarization; Drying; Ethanol; Ethanol - metabolism; Fermentation; Gene expression; Glutathione; Glutathione - metabolism; heat shock protein; Heat shock proteins; High resistance; Malolactic fermentation; Oenococcus - chemistry; Oenococcus - genetics; Oenococcus - physiology; Oenococcus oeni; Proteomics; Resistance factors; Starter cultures; Stress; stress response; Stress, Physiological; Stresses; Transcription; Transcription, Genetic; Wine; Wine - analysis; Wine - microbiology; Wines; heat shock protein; comparative proteomics; stress response; Oenococcus oeni; cross-protection
• ISSN: 0022-5142; 1097-0010
• DOI: 10.1002/jsfa.10921

BACKGROUND During winemaking, malolactic fermentation (MLF) is usually induced by Oenococcus oeni owing to its high resistance to wine stress factors. To ensure a controlled and efficient MLF process, starter cultures are inoculated in wine. In previous studies, O. oeni strains with sub‐lethal acid or ethanol stresses showed higher freeze‐drying vitality and better MLF performance. To explore the mechanisms involved, influences of acid and ethanol stresses on O. oeni SD‐2a were investigated in this study to gain a better understanding of the cross‐protection responses. RESULTS The results showed that acid and ethanol stresses both caused damage to cell membranes and decreased cellular adenosine triphosphate concentration. At the same time, acid stress increased the uptake of glutathione, while ethanol stress led to cell depolarization. The results of comparative proteomic analysis highlighted that heat shock protein was induced with almost all acid and ethanol stresses. In addition, the expression of stress‐relevant genes (hsp20, clpP, trxA, ctsR, recO, usp) increased greatly with ethanol and acid stress treatments. Finally, the viability of O. oeni was improved with acid and ethanol pretreatments after freeze‐drying. CONCLUSIONS This study demonstrated that acid and ethanol stresses had mixed influences on O. oeni SD‐2a. Some physiological and molecular changes would contribute to a more stress‐tolerant state of O. oeni, thereby improving the viability of lyophilized cells. © 2020 Society of Chemical Industry