Estudio de la comunidad de Lactobacillus desarrollada en carnes frescas conservadas al vacío mediante análisis molecular directo

CECILIA FONTANA; PIER SANDRO COCCONCELLI; GRACIELA VIGNOLO

Tucumán, Argentina

Simposio; II Simposio Internacional de Bacterias Lácticas. Primer encuentro Red BAL Argentina.; 2006

CERELA-CONICET

In this study the application of independent culture methods to study the Lactobacillus succession dynamics in vacuum-packaged beef stored at 2 and 8ºC during 9 weeks and 14 days, respectively is described. DNA was extracted directly from meat samples through the applications of species-specific PCR techniques and Real Time-PCR analysis (RT-PCR). The 16S/23S rRNA spacer region was amplified using specie-specific primers allowing the accurate discrimination between L. sakei and L. curvatus species during the complete storage period. Quantitative RT-PCR assays were applied to estimate the numbers (CFU/g) of L. sakei and L. curvatus among total Lactobacillus populations during meat storage. Three separate quantitative reaction were performed being total Lactobacillus, L. sakei and L. curvatus  number estimated by comparing the Ct  (Cycle threshold) values obtained with the respective standard curve. During storage period a strong dominance of L. curvatus was demonstrated by both molecular techniques.