Effect of Iron-Free and Metal-Bound Forms of Lactoferrin on the Growth of Bifidobacteria, E. coli and S. aureus

Abstract

The effects of iron-free lactoferrin (apo-LF) and several metal-bound forms of this protein (Fe-LF, Cu-LF, Zn-LF) on the growth of Bifidobacterium strains, Escherichia coli and Staphylococcus aureus were investigated. Apo-LF, Cu-LF and Zn-LF inhibited the growth of E. coli and S. aureus. The growth inhibitory effect of Cu-LF and Zu-LF was much stronger than that of apo-LF, while Fe-LF was ineffective or only slightly effective. On the other hand, apo-LF, Cu-LF and Fe-LF promoted the growth of Bifidobacterium strains, as indicated by both an increase in culture OD and an increase in the number of viable cells. This growth-promoting effect disappeared when LF was hydrolyzed by pancreatin.