title: Isolation and characterisation of an enterocin P-producing Enterococcus lactis strain from a fresh shrimp (Penaeus vannamei).
abstract: Screening for lactic acid bacteria (LAB) from fresh shrimp samples (Penaeus vannamei) collected from retail seafood markets in the Tunisian's coast, resulted in the isolation of an Enterococcus strain termed Q1. This strain was selected for its antagonistic activity against pathogenic bacteria such as Listeria monocytogenes, Pseudomonas aeruginosa, Lactococcus garvieae and against fungi (Aspergillus niger and Fusarium equiseti). The Q1 strain was characterised using standard morphological and biochemical tests, growth assays at different temperatures, pH and salinity. 16S rRNA, rpoA and pheS gene sequencing, as well as the 16S-23S rRNA intergenic spacer analyses, were combined to identify strain Q1 as a strain of Enterococcus lactis. The bacteriocin produced by E. lactis Q1 is thermostable, active in the pH range from 4.0 to 9.0 and has a bactericidal mode of action. The enterocin P structural gene was detected by specific PCR in strain E. lactis Q1, which is in good agreement with SDS-PAGE data of the purified bacteriocin. A lack of significant antibiotic resistance genes and virulence determinants was confirmed by specific PCRs. This work provides the first description of an enterocin P producer E. lactis strain isolated from a fresh shrimp. Based on its safety properties (absence of haemolytic activity, virulence factors and antibiotic resistance genes), this strain has the potential to be used as a natural additive or adjunct protective culture in food biopreservation and/or probiotic culture.
authors.affiliation: Laboratory of Biochemistry and Technobiology LR01ES05, Faculty of Science of Tunis, University of Tunis El-Manar, Campus Universitaire El-Manar II Tunis, Tunis, Tunisia.
authors.forename: Olfa
authors.initials: O
authors.lastname: Ben Braïek
authors.affiliation: Laboratory of Biochemistry and Technobiology LR01ES05, Faculty of Science of Tunis, University of Tunis El-Manar, Campus Universitaire El-Manar II Tunis, Tunis, Tunisia.
authors.forename: Hamdi
authors.initials: H
authors.lastname: Ghomrassi
authors.affiliation: Institute of Agricultural Biology and Biotechnology, Italian National Research Council (CNR IBBA), Via Einstein s/n, 26900, Lodi, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Cremonesi
authors.affiliation: Institute of Sciences of Food Production, Italian National Research Council (CNR ISPA), Via Celoria 2, 20133, Milan, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Morandi
authors.affiliation: Université de Brest, EA3882, Laboratoire Universitaire de Biodiversité et d'Ecologie Microbienne, IUT de Quimper, 6 Rue de l'Université Quimper, 29000, Cedex, France.
authors.forename: Yannick
authors.initials: Y
authors.lastname: Fleury
authors.affiliation: Université de Brest, EA3882, Laboratoire Universitaire de Biodiversité et d'Ecologie Microbienne, IUT de Quimper, 6 Rue de l'Université Quimper, 29000, Cedex, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Le Chevalier
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Ibn El Jazzar, UR12-ES03, Sousse, Tunisia.
authors.forename: Khaled
authors.initials: K
authors.lastname: Hani
authors.affiliation: Laboratory of Biochemistry and Technobiology LR01ES05, Faculty of Science of Tunis, University of Tunis El-Manar, Campus Universitaire El-Manar II Tunis, Tunis, Tunisia.
authors.forename: Omrane
authors.initials: O
authors.lastname: Bel Hadj
authors.affiliation: Laboratory of Biochemistry and Technobiology LR01ES05, Faculty of Science of Tunis, University of Tunis El-Manar, Campus Universitaire El-Manar II Tunis, Tunis, Tunisia. taoufik_ghrairi@yahoo.fr.
authors.forename: Taoufik
authors.initials: T
authors.lastname: Ghrairi
mesh_terms: D000818:Animals; D001430:Bacteriocins / Q000378:metabolism*; D016983:Enterococcus / Q000235:genetics / Q000378:metabolism*; D033561:Penaeidae / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S; D014774:Virulence
chemical_list: D001430:Bacteriocins; D012336:RNA, Ribosomal, 16S; C417717:enterocin P
keywords: Antibiotic resistance; Bacteriocin; Enterococcus lactis; Lactic acid bacteria; Shrimps; Virulence factors