The growth of Bacillus cereus was markedly inhibited by the addition of lactoferrin and was recovered by the addition of FeCl₃. The growth inhibition was also reversed by the addition of erythrocytes and hemoglobin.B. cereus can use heme or heme-protein complex (hemoglobin-haptoglobin and hematin-albumin complexes) as iron sources in iron deficient conditions. Therefore, B. cereus uses these heme or heme-protein complexes to prevent the growth inhibition of lactoferrin in vivo.