Bacterial diversity of Darfiyeh, a Lebanese artisanal raw goat's milk cheese

Abstract

In order to contribute to the preservation of the Lebanese dairy heritage, the aim of this study was to characterize the Darfiyeh cheese, a traditional variety made from raw goat's milk and ripened in goat's skin. Three independent batches of Darfiyeh production were analyzed after 20, 40 and 60 days of ripening. Mesophilic lactobacilli, thermophilic coccal-shaped lactic acid bacteria (LAB) and thermophilic lactobacilli were enumerated. In order to explore the Darfiyeh natural ecosystem, a combination of phenotypical and molecular approaches was applied. The latter included Polymerase Chain Reaction-temporal temperature gel electrophoresis (PCR-TTGE), classical PCR and quantitative PCR. These methods revealed the presence of Streptococcus thermophilus, Enterococcus faecium, Enterococcus durans, Enterococcus faecalis, Enterococcus malodoratus, group D Streptococcus sp., Lactococcus lactis subsp. lactis and L. lactis subsp. cremoris, Lactobacillus plantarum, Lactobacillus curvatus, Staphylococcus haemolyticus, Escherichia coli, Clostridium sp./ Eubacterium tenue. Real-time PCR enabled quantification of E. faecium, with a detection of 10 7–10 9 cfu g −1 of product. The present molecular approaches combined with phenotypic method allowed describing the complex natural ecosystem of Darfiyeh, giving useful information for the preservation of Lebanese artisanal dairy products.