MALDI-TOF mass spectrometry for the identification of Serbian artisanal cheeses microbiota

Abstract

The study was carried out on 110 bacterial isolates obtained from Baird-Parker agar plates (n = 47) and de Man, Rogosa, Sharpe agar plates with added sorbic acid (n = 63), which were analyzed by MALDI-TOF mass spectrometry. Among 47 non-staphylococcal Baird-Parker agar isolates, Macrococcus caseolyticus was the most abundant (n = 37), followed by Enterococcus faecalis (n = 6). Corynebacterium aurimucosum, Corynebacterium glutamicum, Cronobacter sakazakii, and Enterococcus faecium were also identified. Among 63 non-Lactobacillus isolates, 18 isolates were identified as Leuconostoc mesenteroides, 17 as Enterococcus faecalis, 14 as Lactococcus lactis, 5 as Enterococcus durans, 5 as Lactococcus garvieae, 2 as Leuconostoc pseudomesenteroides, and 2 as Pediococcus pentosaceus. Enterococcus faecalis was the only species obtained from both types of media. All isolates were successfully identified to the species level. According to the results of this study, MALDI-TOF mass spectrometry proved to be useful tool for the identification of selected lactic acid bacteria and Baird-Parker agar isolates from artisanal cheeses.