Functional Genomic Analysis of the Adaptive Response of Enterococcus mundtii CRL35 in a Meat Model.

BONACINA J; SUAREZ NADIA; SAAVEDRA L

Mar del Plata

Congreso; SAIB - 51 Annual Meeting Argentine Society for Biochemistry and Molecular Biology; 2015

During the last decades, reports about enterococci used as starter cultures or co-cultures (adjuncts) in the productionof artisanal fermented products, have increased significantly. Previous studies showed that Enterococcus mundtiiCRL35 (CRL35) was able to grow in culture media containing meat extract. Here, its growth (OD600, UFC/ml andpH), antimicrobial activity and global stress response (2D electrophoresis), in a chemically defined mediumsupplemented with meat proteins (CDMP) in comparison with a non-supplemented (CDM), were first evaluated. As aresult, it was found that CRL35 was able to grow properly reaching the late log phase after 14h at 25 ºC, with 6.60 ×108 UFC/ml and pH=6.09 in CDMP, and 5.90 × 108 UFC/ml and pH=6.15 in CDM. Additionally, in both conditions,CRL35 was capable of inhibit the pathogen Listeria monocytogenes by the action of Enterocin CRL35. Secondly, a gene expression analysis was performed in a sterile meat extract, through RNAseq. Consistent with the expected metabolic adaptations, genes related to proteins and carbohydrates metabolism, and to stress response, wereidentified. These results demonstrated that CRL35 is well adapted to the meat environment, representing a promisingfunctional adjunct culture able to retain its technological and bioprotective properties, to ensure the sensory andhygienic quality of the final product.