Phenotypic and PCR-based characterization of the microflora in Norvegia cheese during ripening.
Microbiological sampling of Norvegia cheese from three cheese factories was done during ripening. The evolution of aerobic mesophilic bacteria, lactococci, lactobacilli, enterococci, presumptive leuconostoc and pediococci was investigated after 30, 90, 180 and 270 days of ripening. Isolates (135) of non-starter lactic acid bacteria (NSLAB) from nine Norvegia cheeses after 90, 180 and 270 days of ripening were examined. The isolates were tested by physiological and biochemical assays, species-specific PCR and 16S rDNA sequencing. After 90 days of ripening Leuconostoc spp., most probably from the starter, and the NSLAB specie Lactobacillus paracasei dominated among the isolates, however, after longer ripening Lb. paracasei dominated. The development and evolution of the microflora in Norvegia varied according to dairy and ripening time.
Østlie
Hilde Marit
HM
Department of Chemistry, Biotechnology and Food Science, Agricultural University of Norway, P.O. Box 5003, N-1432 As, Norway. hilde.ostlie@ikbm.nlh.no
Eliassen
Lise
L
Florvaag
Angelika
A
Skeie
Siv
S
D002611:Cheese / Q000382:microbiology*; D015169:Colony Count, Microbial; D004269:DNA, Bacterial / Q000032:analysis; D004275:DNA, Ribosomal / Q000032:analysis; D005285:Fermentation; D005516:Food Microbiology; D007778:Lactobacillus / Q000235:genetics* / Q000302:isolation & purification; D007934:Leuconostoc / Q000235:genetics* / Q000302:isolation & purification; D010641:Phenotype; D016133:Polymerase Chain Reaction; D013997:Time Factors
D004269:DNA, Bacterial; D004275:DNA, Ribosomal