Mode of action, purification and amino acid sequence of plantaricin C19, an anti-Listeria bacteriocin produced by Lactobacillus plantarum C19

Plantaricin C19, an anti-Listeria bacteriocin, was successfully purified by adsorption to and release from producing cells at low pH combined with rev erse phase high-performance liquid chromatography (HPLC). The purification resulted in a 900-fold increase in specific activity with a yield of 15% of the original activity. Mass spectrometry analysis gave a molecular weight of 3845.3. Protein microsequencing identified 36 amino acids. Plantaricin C 19 is rich in both hydrophobic and basic amino acids in good accordance wit h its basic and hydrophobic character. Comparison of the amino acid sequenc e of plantaricin C19, with the sequence of some other anti-Listeria bacteri ocins produced with lactic acid bacteria, revealed that plantaricin C19 has in its N-terminal region the consensus sequence-YYGNGL-(uniquely with Vali ne instead of Leucine as found in all other bacteriocins), identifying plan taricin C 19 as a pediocin-like bacteriocin. Plantaricin C 19 exerted a bac teriostatic action on sensitive cells of Listeria grayi IP 6818 in BHT brot h. No loss of intracellular K+, Mg2+ or UV-absorbing materials was observed . Adsorption of plantaricin C19 on L. grayi CIP 6818 decreased in the prese nce of salts. (C) 2001 Elsevier Science B.V. All rights reserved.