Under acidic conditions, 2,4-hexadienol isomerizes to s -sorbic alcohol (1,3-hexadienol). Oenococcus oeni strains are well-known for their considerable phenotypic variations in terms of tolerance to harsh wine conditions and malolactic activity. Oenococcus oeni is a lactic acid bacterium highly adapted to the stressful environment of wine, and is widely used as an industrial starter culture to conduct malolactic fermentation (MLF), the conversion of L‐malate to L‐lactate. oeni, a facultative anaerobe, is one of the most acid- and alcohol tolerant LAB. Oenococcus oeni (formerly called Leuconostoc oenos) is a lactic acid bacterium (LAB) that occurs naturally in fruit mashes and related habitats.O. In a process called malolactic conversion, O. oeni's job is to "de-acidify" the wine and create a full, rounded mouth-feel. Ethanol tolerance is a crucial feature for the activity of O. oeni cells in wine because ethanol acts as a disordering agent of its cell membrane and negatively affects metabolic activity; it damages the membrane integrity, decreases cell viability and, as other stress conditions, delays the start of malolactic fermentation with a consequent alteration of wine quality. Some strains of Lactobacillus and most strains of Oenococcus oeni can metabolize sorbic acid to p -sorbic alcohol (2,4-hexadienol). oeni is employed in wineries to carry out the malolactic conversion, an important secondary fermentation in the production of wine.O. Some cold‐climate wine regions still produce wines which prove too stressful for the application of a starter culture, resulting in sluggish or stuck MLFs which compromise the quality and stability of the wine. Domain: Bacteria Phylum: FirmicutesClass: Bacilli Order: Lactobacillales Family: Leuconostocaceae Genus: Oenococcus Species: oeni (1)NCBIlink to find] Genomic subtractive hybridization (SH) between two isolates with differing enological potentials was used to elucidate the genetic bases of this intraspecies diversity and identify novel genes involved in adaptation to wine. In turn, upon reaction with ethanol it can form an ester, 2-ethoxyhexa-3,4-diene.