Fig. 1: Different taxonomic profiles are present in cheese and environmental swabs.

A. Taxonomic composition of the 30 most abundant species in all samples, with the average relative abundances of each species in each category. B. Alpha diversity, in terms of observed species, Shannon and Simpson analysis of samples by category, and (C) beta diversity analysis represented by a Principal-Coordinate Analysis (PCoA) plot of Bray-Curtis distance, with ellipses representing clustering by category. Boxes represent the interquartile range (IQR) between the first and third quartiles, and the line inside represents the median (2nd quartile). Whiskers denote the lowest and the highest values within 1.5 x IQR from the first and third quartiles, respectively. The significance was tested by applying pairwise Wilcoxon test. Average values are obtained from n = 308, 199, 37, 524, and 182 biologically independent samples from food contact, non food contact, operators’ swabs, final products and cheese-related materials, respectively. The category “cheese-related materials” groups together milk, brine and whey culture.