Functional genomic analysis of the adaptive response of Enterococcus mundtii CRL35 in a meat model

BONACINA, J; SUÁREZ, N; FADDA S; SAAVEDRA L

MAR DEL PLATA

Congreso; SAIB; 2015

SAIB

During the last decades, reports about enterococci used as starter cultures or co-cultures (adjuncts) in the production of artisanal fermented products, have increased significantly. Previous studies showed that Enterococcus mundtii CRL35 (CRL35) was able to grow in culture media containing meat extract. Here, its growth (OD600, UFC/ml and pH), antimicrobial activity and global stress response (2D electrophoresis), in a chemically defined medium supplemented with meat proteins (CDMP) in comparison with an unsupplemented (CDM), were first evaluated. As a result, 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, were identified. These results demonstrated that CRL35 is well adapted to the meat environment, representing a promising functional adjunct culture able to retain its technological and bioprotective properties, to ensure the sensory and hygienic quality of the final product