Isolation of Antimicrobial Peptides from Copper-Containing Biopeptide derived from Yeast

Antimicrobial resistance has created an urgent need for novel bioactive compounds from natural sources. This study explores the antimicrobial peptides isolated from copper-enriched yeast extracts. Fractionation by molecular weight revealed that both >30 kDa and <3 kDa copper-bound fractions exhibited significant antifungal activity, whereas intermediate and non-copper-bound fractions showed little or no effect. Further purification using RP-HPLC and Prep HPLC yielded multiple peptide peaks. Among these, two subfractions from the >30 kDa group (fractions 9 and 10) and one from the <3 kDa group (fraction 15) displayed the strongest inhibitory activity against Candida albicans. UV-Vis spectral analysis highlighted distinct absorption characteristics of bioactive fractions, suggesting structural and copper-binding heterogeneity. These findings suggest that yeast is an inexpensive and readily available natural source for obtaining peptides, which exhibit strong antifungal activity against Candida albicans when bound to copper. Therefore, such peptides can be considered promising candidates for use in the food and cosmetic applications. Future research should focus on optimizing production, scaling up purification processes, and evaluating their potential for industrial applications.