Sensitivity of Pseudomonas syringae to Bovine Lactoferrin Hydrolysates and Identification of a Novel Inhibitory Peptide.
The antimicrobial activity of bovine lactoferrin hydrolysates (bLFH) was measured against Pseudomonas strains (P. syringae and P. fluorescens) in vitro. To compare susceptibility to bLFH, minimal inhibitory concentration (MIC) values were determined using chemiluminescence assays and paper disc plate assays. Antimicrobial effect against P. fluorescens was not observed by either assay, suggesting that bLFH did not exhibit antimicrobial activity against P. fluorescens. However, a significant inhibition of P. syringae growth was observed in the presence of bLFH. The addition of bLFH in liquid or solid medium inhibited growth of P. syringae in a dose-dependent manner. Furthermore, a bLFH peptide with antimicrobial activity toward P. syringae was isolated and identified. The N-terminal amino acid sequences of thus obtained antimicrobial bLFH peptides were analyzed by a protein sequencer and were found to be Leu-Arg-Ile-Pro-Ser-Lys-Val-Asp-Ser-Ala and Phe-Lys-Cys-Arg-Arg-Trp-Gln-Trp-Arg-Met. The latter peptide sequence is known to be characteristic of lactoferricin. Therefore, in the present study, we identified a new antimicrobial peptide against P. syringae, present within the N-terminus and possessing the amino acid sequence of Leu-Arg-Ile-Pro-Ser-Lys-Val-Asp-Ser-Ala.
Department of Animal Life and Environmental Science, Hankyong National University, Anseong 17579, Korea.
Woan-Sub
WS
Kim
Department of Molecular Bioscience, School of Biomedical Science, Kangwon National University, Chuncheon 24341, Korea.
Pyeung-Hyeun
PH
Kim
Dairy Food Science Laboratory, Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan.
Kei-Ichi
K
Shimazaki
Pseudomonas; antimicrobial activity; lactoferricin; lactoferrin; milk