Surface microbiota analysis of Taleggio, Gorgonzola, Casera, Scimudin and Formaggio di Fossa Italian cheeses

The composition of the bacterial consortia of the smear Italian cheeses and their role on quality and safety is still poorly understood. The objective of this study was to identify and characterize the bacterial communities present on the surface of five traditional Italian cheeses, Casera Valtellina, Scimudin, Formaggio di Fossa, Gorgonzola and Taleggio. DGGE analysis performed using total DNA obtained from cheese surfaces enabled us to identify the dominant bacterial populations. Bands showing different intensity and identified as Staphylococcus, Micrococcus, Psychrobacter, Enterococcus and Brevibacterium species were detected on the surface of cheeses. The cluster analysis showed that Gorgonzola, Taleggio and Formaggio di Fossa cheeses present high similarity in their surface bacterial composition while major differences in the DGGE profiles were observed in Scimudin and Casera. The molecular taxonomical identification among the Gram positive isolates, reveals the presence of the following bacterial genera: Staphylococcus, Micrococcus, Macrococcus, Enterococcus, Lactobacillus, Carnobacterium, Leuconostoc, Brevibacterium, Corynebacterium, Brochothrix, Bacillus. The combination of culture dependent and independent techniques allowed us to obtain information about the bacterial species covering the surface of five different traditional Italian cheeses.