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

D'ANGELO; GABRIELA MARTINO; PABLO MORTERA; VÍCTOR S. BLANCATO; MARTÍN ESPARIZ; CHRISTIAN MAGNI; SERGIO ALARCÓN

Simposio; 2nd Latin American Metabolic Profiling Symposium; 2016

  Enterococci are Lactic Acid Bacteria (LAB) usually found in human and animal gut microbiota and widely distributed in diverse habitats such as dairy and fermentedfoods. Although they have been associated to nosocomial infections, Enterococcus have a desirable technological aspect because their positive contribution to flavordevelopment in madurated cheeses. Citrate, proteins and amino acids (AA) catabolism are the main pathways that influence flavor in cheese.Here, we analyzed the presence of genes related to amino acids degradation in the genomes of three E. faecium strains (GM70, GM75 and IQ110) and one E. durans strain(IQ23). These four strains have different citrate properties and diactelyl/acetoin production: IQ23, GM70 and GM75 are a cit +  strains and produced diacetyl/acetoin when theygrown in LB medium supplemented with citrate. IQ110 is a cit − strain and not significant amount of diacetyl/acetoin production was observed. In this presentation, the volatileorganic compounds derived from branched-chain amino acid (BcAAs) degradation by resting cells, were analyzed using solid-phase microextraction (SPME) combined with gaschromatography-mass spectrometry (GC-MS). The volatile profiles obtained were well correlated with the genomic analysis.This study is part of the first stage of characterization of new isolates for the rational design of strains of technological impact on regional production of cheese