Abstract
We experimentally determined that bacteriocin-like inhibitory substances synthetized by Oenococcus oeni may act as a natural preservative and may thus be of importance for the wine industry. An O. oeni strain isolated from wine was tested for antimicrobial activity against ten indicator lactic acid wine spoilage bacteria of enological origin from the genera Lactobacillus, Leuconostoc, and Pediococcus. A strong competition effect of O. oeni against all the tested indicator bacteria was noted. The antimicrobial extracellular metabolites were produced at the end of O. oeni’s exponential growth phase and the maximum activity occurred between hours 15 and 20 of cultivation. The bioactive compounds synthetized by O. oeni were found to be strain-specific. Their bactericidal activity was stable at high temperatures (100 °C, 20 min) and in low pH environments (with the greatest activity at pH 2–8), but was totally degraded by proteolytic enzymes (pronase E, proteinase K, trypsin, pepsin, and α-chymotrypsin). They can thus be classified as heat-resistant proteins active at low pH. The dynamics of the biosynthesis and their activity were temperature-dependent, being best at 20 °C. Our results indicate that the use of an O. oeni starter culture with the appropriate antimicrobial potential may be a useful tool in winemaking procedures to control microbial stability and inhibit wine spoilage.
Highlights
Oenococcus oeni is Gram-positive, heterofermentative bacteria commonly used in winemaking
Malolactic bacteria (MLB) use up residual sugars left by yeast after alcoholic fermentation, and they metabolize malic acid, which could act as a carbon source for spoilage microflora
One isolate of Oenococcus oeni was tested for synthesis of bacteriocin-like inhibitory substances (BLIS)
Summary
Oenococcus oeni is Gram-positive, heterofermentative bacteria commonly used in winemaking. The strains perform malolactic fermentation (MLF) and are currently used in commercial starter cultures for controlled malolactic fermentation. This specific process of secondary fermentation takes place after the alcoholic fermentation and involves the bioconversion of malic acid into lactic acid. Malolactic bacteria (MLB) use up residual sugars left by yeast after alcoholic fermentation, and they metabolize malic acid, which could act as a carbon source for spoilage microflora. Malolactic bacteria, as lactic acid bacteria (LAB), are able to biosynthesize bacteriocins. These are low-molecular peptide compounds with antimicrobial properties secreted by some bacteria to inhibit the growth and activity of competing microorganisms [6, 7]. The bacteriocins produced by LAB are perceived as
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
