Antibacterial activity of cerein 8A, a bacteriocin-like peptide produced by Bacillus cereus Authors Delmar Bizani Department of Food Sciences, ICTA, Rio Grande do Sul Federal University, Porto Alegre, Brazil; and Centro Universitário La Salle, Canoas, Brazil Amanda S. Motta Department of Food Sciences, ICTA, Rio Grande do Sul Federal University, Porto Alegre, Brazil Juliana A.C. Morrissy Department of Food Sciences, ICTA, Rio Grande do Sul Federal University, Porto Alegre, Brazil Renata M.S. Terra Department of Chemistry, Rio Grande do Sul Catholic University, Porto Alegre, Brazil André A. Souto Department of Chemistry, Rio Grande do Sul Catholic University, Porto Alegre, Brazil Adriano Brandelli Department of Food Sciences, ICTA, Rio Grande do Sul Federal University, Porto Alegre, Brazil Keywords: Bacillus cereus, Listeria monocytogenes, antimicrobial peptides, bacteriocins, infrared spectroscopy Abstract The mode of action of cerein 8A, a bacteriocin produced by the soil bacterium Bacillus cereus 8A, was investigated. The effect of cerein 8A was tested against Listeria monocytogenes and a bactericidal effect at 400 arbitrary units (AU)/ml was observed. In addition, cerein 8A was bactericidal against Bacillus cereus at 200 AU/ml, and inhibited the growth of Escherichia coli and Salmonella Enteritidis. Stronger inhibition of these gram-negative bacteria was achieved when the chelating agent EDTA was added together with bacteriocin. The effect of cerein 8A on B. cereus and L. monocytogenes was also investigated by Fourier transform infrared spectroscopy (FTIR). Treated cells had an important frequency increase at 2920 cm–1 and a decrease at 1400 cm–1, corresponding to assignments of fatty acids. Transmission electron microscopy showed damaged cell walls and loss of protoplasmic material. These results suggest that the mode of action of cerein 8A is to interfere with cell membranes and the cell wall. [Int Microbiol 2005; 8(2):125-131] Downloads PDF Published 2010-02-27 Issue Vol. 8 No. 2 (2005) Section Research Articles License Submission of a manuscript to International Microbiology implies: that the work described has not been published before, including publication in the World Wide Web (except in the form of an Abstract or as part of a published lecture, review, or thesis); that it is not under consideration for publication elsewhere; that all the coauthors have agreed to its publication. The corresponding author signs for and accepts responsability for releasing this material and will act on behalf of any and all coauthors regarding the editorial review and publication process.If an article is accepted for publication in International Microbiology, the authors (or other copyright holder) must transfer to the journal the right–not exclusive–to reproduce and distribute the article including reprints, translations, photographic reproductions, microform, electronic form (offline, online) or any other reproductions of similar nature. Nevertheless, all article in International Microbiology will be available on the Internet to any reader at no cost. The journal allows users to freely download, copy, print, distribute, search, and link to the full text of any article, provided the authorship and source of the published article is cited. The copyright owner's consent does not include copying for new works, or resale. In these cases, the specific written permission of International Microbiology must first be obtained.Authors are requested to create a link to the published article on the journal's website. The link must be accompanied by the following text: "The original publication is available on LINK at <http://www.im.microbios.org>. Please use the appropiate URL for the article in LINK. Articles disseminated via LINK are indexed, abstracted, and referenced by many abstracting and information services, bibliographic networks, subscription agencies, library networks, and consortia.