The invention relates to a fraction of peptides and/or proteins that are derived from egg white and that are capable of binding heparin, for its anti-Listeria monocytogenes action. The invention also relates to a molecule of sequence SEQ ID No. 1 for its antimicrobial action, and in particular anti-Listeria monocytogenes action.Linvention concerne une fraction de peptides et/ou protéines issus du blanc dœuf et aptes à lier lhéparine, pour son action anti- Listeria monocytogenes. Linvention concerne également une molécule de séquence SEQ ID n°1 pour son action anti-microbienne, et notamment anti- Listeria monocytogenes.