C-B Hu1, T Zendo, J Nakayama, K Sonomoto. 1. Laboratory of Microbial Technology, Division of Microbial Science and Technology, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, Higashi-ku, Fukuoka, Japan.
Abstract
AIMS: To characterize the novel bacteriocin produced by Enterococcus durans. METHODS AND RESULTS: Enterococcus durans QU 49 was isolated from carrot and expressed bactericidal activity over 20-43 degrees C. Bacteriocins were purified to homogeneity using the three-step purification method, one of which, termed durancin TW-49M, was an enterocin B-homologous peptide with most identical residues occurring in the N-terminus. Durancin TW-49M was more tolerant in acidic than in alkali. DNA sequencing analysis revealed durancin TW-49M was translated as a prepeptide of the double-glycine type. Durancin TW-49M and enterocin B expressed similar antimicrobial spectra, in which no significant variation due to the diversity in their C-termini was observed. CONCLUSIONS: Durancin TW-49M, a novel nonpediocin-like class II bacteriocin, was characterized to the amino acid and genetic levels. The diverse C-terminal parts of durancin TW-49M and enterocin B were hardly to be suggested as the place determining the target cell specificity. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first and comprehensive study of a novel bacteriocin produced by Ent. durans. The high homology at the N-terminal halves between durancin TW-49M and enterocin B makes them suitable to study the structure-function relationship of bacteriocins and their immunity proteins.
AIMS: To characterize the novel bacteriocin produced by Enterococcus durans. METHODS AND RESULTS:Enterococcus durans QU 49 was isolated from carrot and expressed bactericidal activity over 20-43 degrees C. Bacteriocins were purified to homogeneity using the three-step purification method, one of which, termed durancin TW-49M, was an enterocin B-homologous peptide with most identical residues occurring in the N-terminus. Durancin TW-49M was more tolerant in acidic than in alkali. DNA sequencing analysis revealed durancin TW-49M was translated as a prepeptide of the double-glycine type. Durancin TW-49M and enterocin B expressed similar antimicrobial spectra, in which no significant variation due to the diversity in their C-termini was observed. CONCLUSIONS:Durancin TW-49M, a novel nonpediocin-like class II bacteriocin, was characterized to the amino acid and genetic levels. The diverse C-terminal parts of durancin TW-49M and enterocin B were hardly to be suggested as the place determining the target cell specificity. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first and comprehensive study of a novel bacteriocin produced by Ent. durans. The high homology at the N-terminal halves between durancin TW-49M and enterocin B makes them suitable to study the structure-function relationship of bacteriocins and their immunity proteins.