title: Surface microbial consortia from Livarot, a French smear-ripened cheese.
abstract: The surface microflora (902 isolates) of Livarot cheeses from three dairies was investigated during ripening. Yeasts were mainly identified by Fourier transform infrared spectroscopy. Geotrichum candidum was the dominating yeast among 10 species. Bacteria were identified using Biotype 100 strips, dereplicated by repetitive extragenic palindromic PCR (rep-PCR); 156 representative strains were identified by either BOX-PCR or (GTG)(5)-PCR, and when appropriate by 16S rDNA sequencing and SDS-PAGE analysis. Gram-positive bacteria accounted for 65% of the isolates and were mainly assigned to the genera Arthrobacter , Brevibacterium , Corynebacterium , and Staphylococcus . New taxa related to the genera Agrococcus and Leucobacter were found. Yeast and Gram-positive bacteria strains deliberately added as smearing agents were sometimes undetected during ripening. Thirty-two percent of the isolates were Gram-negative bacteria, which showed a high level of diversity and mainly included members of the genera Alcaligenes , Hafnia , Proteus , Pseudomonas , and Psychrobacter . Whatever the milk used (pasteurized or unpasteurized), similar levels of biodiversity were observed in the three dairies, all of which had efficient cleaning procedures and good manufacturing practices. It appears that some of the Gram-negative bacteria identified should now be regarded as potentially useful in some cheese technologies. The assessment of their positive versus negative role should be objectively examined.
authors.affiliation: Université de Caen Basse-Normandie, Unité des Microorganismes d'Intérêt Laitier et Alimentaire, E.A. 3213, IFR 146 ICORE, 14032 Caen CEDEX, France.
authors.forename: Sandra
authors.initials: S
authors.lastname: Larpin-Laborde
authors.forename: Muhammad
authors.initials: M
authors.lastname: Imran
authors.forename: Catherine
authors.initials: C
authors.lastname: Bonaïti
authors.forename: Nagamani
authors.initials: N
authors.lastname: Bora
authors.forename: Roberto
authors.initials: R
authors.lastname: Gelsomino
authors.forename: Stefanie
authors.initials: S
authors.lastname: Goerges
authors.forename: Françoise
authors.initials: F
authors.lastname: Irlinger
authors.forename: Michael
authors.initials: M
authors.lastname: Goodfellow
authors.forename: Alan C
authors.initials: AC
authors.lastname: Ward
authors.forename: Marc
authors.initials: M
authors.lastname: Vancanneyt
authors.forename: Jean
authors.initials: J
authors.lastname: Swings
authors.forename: Siegfried
authors.initials: S
authors.lastname: Scherer
authors.forename: Micheline
authors.initials: M
authors.lastname: Guéguen
authors.forename: Nathalie
authors.initials: N
authors.lastname: Desmasures
mesh_terms: D000818:Animals; D044822:Biodiversity; D002611:Cheese / Q000382:microbiology*; D015169:Colony Count, Microbial; D004591:Electrophoresis, Polyacrylamide Gel; D005516:Food Microbiology; D006090:Gram-Negative Bacteria / Q000235:genetics / Q000302:isolation & purification*; D006094:Gram-Positive Bacteria / Q000235:genetics / Q000302:isolation & purification; D059013:Microbial Consortia; D008892:Milk; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D017550:Spectroscopy, Fourier Transform Infrared; D015003:Yeasts / Q000235:genetics / Q000302:isolation & purification
chemical_list: D012336:RNA, Ribosomal, 16S