title: Are Enterococcus populations present during malolactic fermentation of red wine safe?
abstract: The aim of this study was the genetic characterisation and safety evaluation of 129 Enterococcus isolates obtained from wine undergoing malolactic fermentation. Genetic characterisation by randomly amplified polymorphic DNA-PCR displayed 23 genotypes. 25 isolates representative of all genotypes were identified as Enterococcus faecium by species-specific PCR and assayed for antibiotic resistance, presence of virulence genes and aminobiogenic capacity, both in decarboxylase medium and wine. The aminobiogenic capacity in wine was analysed in presence (assay 1) and absence (assay 2) of Oenococcus oeni CECT 7621. Resistance to tetracycline, cotrimoxazol, vancomycin and teicoplanin was exhibited by 96% of the strains, but none of them harboured the assayed virulence genes. All of the strains harboured the tyrosine decarboxylase (tdc) gene, while 44% were positive for tyramine in decarboxylase medium. Only five out of 25 strains survived in wine after seven days of incubation, and when concentrations of biogenic amines in wines were determined by HPLC, only those wines in which the five surviving strains occurred contained biogenic amines. Histamine, putrescine and cadaverine were detected in wines from both assays, although concentrations were higher in assay 2. Tyramine and phenylethylamine were detected only in absence of O. oeni. This research contributes for the knowledge of safety aspects of enterococci related to winemaking.
authors.affiliation: Department of Analytical Chemistry and Food Technology, Environmental Sciences and Biochemistry Faculty, University of Castilla-La Mancha, Avda. Carlos III, s/n, 45071 Toledo, Spain.
authors.forename: Fátima
authors.initials: F
authors.lastname: Pérez-Martín
authors.affiliation: Department of Analytical Chemistry and Food Technology, Environmental Sciences and Biochemistry Faculty, University of Castilla-La Mancha, Avda. Carlos III, s/n, 45071 Toledo, Spain. Electronic address: susana.sprieto@uclm.es.
authors.forename: Susana
authors.initials: S
authors.lastname: Seseña
authors.affiliation: Institute of Vine and Wine of Castilla-La Mancha, Crta. Toledo-Albacete, s/n, 13700 Tomelloso, Ciudad Real, Spain; Scientific and Technologic Park of Albacete, Paseo de la Innovación 1, 02006 Albacete, Spain.
authors.forename: Pedro Miguel
authors.initials: PM
authors.lastname: Izquierdo
authors.affiliation: Department of Analytical Chemistry and Food Technology, Environmental Sciences and Biochemistry Faculty, University of Castilla-La Mancha, Avda. Carlos III, s/n, 45071 Toledo, Spain.
authors.forename: María Llanos
authors.initials: ML
authors.lastname: Palop
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D044822:Biodiversity; D001679:Biogenic Amines / Q000032:analysis / Q000378:metabolism; D016983:Enterococcus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D005285:Fermentation; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D014920:Wine / Q000032:analysis / Q000382:microbiology*
chemical_list: D001426:Bacterial Proteins; D001679:Biogenic Amines
keywords: Antibiotic resistance; Biogenic amines; Enterococcus; Malolactic fermentation; Virulence genes