Pecorino cheeses metagenome

Autochthonous mesophilic non-starter lactic acid bacteria (NSLAB) were identified from aged ewes’ milk Pecorino Crotonese (PC) cheeses. Leuconostoc mesenteroides subsp. mesenteroides 2A, Lactobacillus casei 23C and Lactobacillus plantarum 18C (Pool 1) and Leuc. mesenteroides subsp. mesenteroides 2A, and L. casei 25D and 16A (Pool 2) were selected based on several enzymatic activities and, separately, used as adjunct cultures. The manufacture of PC cheeses was at industrial plant scale, including the control cheese (CC) without adjuncts and with commercial primary starters. Ripening lasted 105 days at 10°C. Compared to CC, both adjunct cultures only slightly affected the gross chemical composition and pH of PC cheese. The cell density of thermophilic primary starters in CC progressively decreased throughout ripening. As shown by plate count and con?rmed through RAPD-PCR, the cell number of NSLAB in PC cheeses made with adjunct cultures was almost constant throughout ripening. As shown by culture-independent analysis, the OTUs found during ripening varied depending the manufacture with or without adjunct cultures. The major differences among cheeses were the concentration of free amino acids and the synthesis of some key volatile components (VOC). As shown by PT-GC/MS analysis, the levels of ketones, esters, secondary alcohols and sulphur compounds were highest in the cheese manufactured with Pool 1. The cheese made with Pool 2 mainly contained neutral VOC. Compared to CC, Pool 1 positively affected upon overall cheese quality.