Flavor development in Enterococci Faecium group for rational design of strains with technological impact

MORTERA PABLO; MAGNI CHRISTIAN; D'ANGELO MATILDE ELVIRA; BLANCATO VICTOR; ALARCÓN SERGIO; MARTINO GABRIELA; ESPARIZ MARTÍN

Rosario

Simposio; lamps-Second Latin American Metabolic Profilig Symposium; 2016

Enterococci areLactic Acid Bacteria (LAB) usually found in human and animal gut microbiota andwidely distributed in diverse habitats such as dairy and fermented foods.Although they have been associated to nosocomial infections, Enterococcushave a desirable technological aspect because their positive contribution toflavor development in madurated cheeses. Citrate, proteins and amino acids (AA)catabolism are the main pathways that influence flavor in cheese. Here, weanalyzed the presence of genes related to amino acids degradation in thegenomes of three E. faecium strains (GM70, GM75 and IQ110) and one E.durans strain (IQ23). These four strains have different citrate propertiesand diactelyl/acetoin production: IQ23, GM70 and GM75 are a cit+ strainsand produced diacetyl/acetoin when they grown in LB medium supplemented withcitrate. IQ110 is a ci-t strain and not significant amount ofdiacetyl/acetoin production was observed. In this presentation, the volatileorganic compounds derived from branched-chain amino acid (BcAAs) degradation byresting cells, were analyzed using solid-phase microextraction (SPME) combinedwith gas chromatography-mass spectrometry (GC-MS). The volatile profilesobtained were well correlated with the genomic analysis. This study is part of the first stage of characterization of newisolates for the rational design of strains of technological impact on regionalproduction of cheese.