Differential contribution of three lactic acid bacteria strains from a microbial consortium to milk fermentation by untargeted metabolomics and analysis of volatile compounds

In this study, a leave-one-out inoculation strategy was followed for the fermentation of milk using as a starter the strains Lactococcus lactis LA1, Lactococcus cremoris LA10, and Lactiplantibacillus plantarum LA30), which had been found as components of a consortium in a naturally fermented milk (NFM). The dynamics of the individual strains in milk was assessed by culturing and strain-specific qPCR amplification. Metabolites and volatile compounds in the ensuing fermented milks were analysed, respectively, by solid-phase microextraction gas-chromatography (SPME-GC) and high-resolution mass spectrometry liquid chromatography (MS-LC). Metabolomic fingerprinting of fermented milks was performed by high-resolution mass spectrometry using a liquid chromatography (LC) system 1290 Infinity II (Agilent, Santa Clara, CA, USA) coupled to an Agilent 6560B ion mobility quadrupole-time-of-flight mass spectrometer (IM-QTOF MS) equipped with an Agilent G1607A dual Jetstream electrospray ionization (ESI) source. In this data dataset, mzml archives corresponding to positive and negative ionization modes analysis are uploaded.