The effect of microbial gas production in cheese (Fig. 3) was studied by image analysis to determine the size and total number of gas holes and the area on the surfaces of cheese slices occupied by eyes. The gas holes formed in the studied cheeses throughout the ripening process were small (median ≤2 mm2); however, in control cheese, the median eye size during the first week of ripening was significantly higher (p < 0.05) than that in phage-treated cheeses (Fig. 4a). The size of the gas holes evolved throughout maturation following a similar pattern in all three cheese vats, increasing during the first week and decreasing from