As the consumer demand for healthier foods free from chemical preservatives grows, the food industry faces increasing pressure to develop minimally processed, natural, "clean label" products [1]. One promising approach is the use of natural preservatives, such as bioactive metabolites produced by microorganisms. Wickerhamomyces anomalus is a yeast that produces extracellular peptides with biopreservative potential. Previous studies have demonstrated their effectiveness against the spoilage yeast D. bruxellensis and the reference strain S. cerevisiae DBPVG 6500 [2], positioning these peptides as a valuable tool for natural food preservation.

Therefore, this study evaluated the antimicrobial and antioxidant properties of peptides derived from W. anomalus's metabolism. The peptides were obtained by culturing W. anomalus DBVPG 3003 in YEPD medium, followed by ultrafiltration to isolate a 2–10 kDa fraction. Antimicrobial assays demonstrated strong bactericidal activity against Escherichia coli, Listeria monocytogenes, and Salmonella sp. at 1 mg/mL, with CFU reductions of 4–5 orders of magnitude. At 0.5 mg/mL, bacteriostatic effects were observed against L. monocytogenes and Salmonella sp., while the yeast strains (Candida albicans and C. krusei) showed resistance at all of the tested concentrations.

Antioxidant activity, assessed using DPPH and FRAP assays, highlighted the peptides’ substantial radical scavenging and ferric-reducing capabilities. At 1 mg/mL, the peptides achieved a DPPH inhibition of 1856 ± 37.5µM TE/mL and a FRAP value of 5843 ± 220µM TE/mL, demonstrating their strong antioxidant potential.

These results underscore the potential of W. anomalus peptides as natural preservatives for the food industry, enhancing safety, extending shelf life, and supporting the development of healthier "clean label" products. Beyond food applications, their antioxidant and antimicrobial properties also present opportunities in the pharmaceutical, cosmetic, and nutraceutical industries.

References:

[1] Asioli, D., et al. (2017). https://doi.org/10.1016/j.foodres.2017.07.022

[2] Comitini, Fet al. (2004). https://doi.org/10.1111/j.1574-6968.2004.tb09761.x