Purification of a Novel Bacteriocin-Like Inhibitory Substance produced by Enterococcus faecium ICIS 8 and Characterization of Its Mode of Action.
Microb Drug Resist. 2016 Aug 30;
Authors: Vasilchenko AS, Rogozhin EA, Valyshev AV
OBJECTIVE: The aim of this work was to purify and characterize a bacteriocin-like antimicrobial substance produced by an antagonistic active strain of Enterococcus faecium.
METHODS AND RESULTS: A novel bacteriocin-like inhibitory substance (BLIS) produced by the E. faecium ICIS 8 strain was purified and characterized using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and N-terminal amino acid sequencing revealed the following partial sequence: NH2-APKEKCFPKYCV. The proteinaceous nature of purified BLIS was assessed by treatment with proteolytic enzyme. Studies of the action of BLIS using bacteriological and bioluminescence assays revealed a dose-dependent inhibition of Listeria monocytogenes 88BK and Escherichia coli K12 TG1 lac::lux viability. The interaction of the BLIS with the bacterial surface led to the compensation of a negative charge value, as shown by zeta-potential measurements. Assessments of membrane integrity using fluorescent probes and atomic force microscopy revealed the permeabilization of the cellular barrier structures in both L. monocytogenes and E. coli.
CONCLUSION: The novel BLIS from E. faecium ICIS 8 was characterized by a unique primary peptide sequence and exerted bactericidal activity against L. monocytogenes and E. coli by disrupting membrane integrity.
PMID: 27575914 [PubMed - as supplied by publisher]