Before DNA extraction, 2, 6, 9 and 13-month old cheeses weredivided into two fractions and treated differently in order to dis-criminate the DNA from whole and lysed cells, as described by Gattiet al. [13]. The cell-free fraction was obtained by filtration and thewhole-cell fraction was treated with DNase in order to digest freeDNA arising from lysed cells. DNA was extracted from 1 mL of thefiltered untreated fraction (lysed cells) and from 1 mL of the treatedfraction (whole cells).