Inhibition of the wine spoilage yeast Dekkera bruxellensis by bovine lactoferrin-derived peptides

The antimicrobial action of lactoferrin (LF)-derived peptides against Dekkera bruxellensis strains isolated from spoiled wines has been examined. The study included a fifteen-residue peptide (LfcinB17-31) derived from bovine lactoferricin B and a bovine LF pepsin hydrolysate (LFH). In vitro assays showed the inhibitory properties of LfcinB17-31 on D. bruxellensis growth with IC50 and MIC values in the micromolar range. Strains tested showed different sensitivity to the peptide. LfcinB17-31 showed fungicidal properties towards all strains tested in laboratory growth medium. However, the extent of fungicidal activity was strain-dependent in must and wine, confirming the different antimicrobial action of peptides depending on both the food matrix and the target micro-organism. The binding of LfcinB17-31 to D. bruxellensis cells was visualized by fluorescence microscopy and correlated with the fungicidal activity in the different matrixes. LfcinB17-31 and LFH showed growth inhibitory properties in wine suggesting their potential use for spoilage control.