Molecular microbial characterization of naturally fermented llama meat sausages produced in Northwestern Argentina

Argentinean Andean region from the Northwestern side of the country exhibits singular environmental conditions limiting agricultural activities as well as the variety of the local diet. Recently, the importance of llama (Lama glama) meat has increased due to its high protein nutritional value and reduced fat and cholesterol contents. Also, the production of fermented llama meat sausages may contribute to the regional economy development. To increase the knowledge on the safety and quality of these fermented sausages the microbial [lactic acid bacteria (LAB) and pathogenic] communities from fermented llama sausages were analyzed by microbiological (specific culture media) and molecular approaches (RAPD-PCR, species-specific PCR and 16s rDNA sequencing). Sausages (meat 72.4%, pork fat 25%, salt 2%, sucrose 1.5%, nitrite 0.025% and seasonings) were produced in a pilot-plant scale in Jujuy (Northwestern Argentina); samples at days 0, 2, 4, 7, 14, 21, 28 and 35 were collected for microbial identification and population dynamics (DGGE) analyses. A pH decrease from 5.6 to 5.0 while the LAB counts varied from 6.5 to 5.0 log CFU/g were determined throughout the whole fermentation-ripening period. Regarding safety, no Staphylococcus aureus, Salmonella and Listeria monocytogenes strains were found while Escherichia coli counts were within the acceptable EFSA standards. Concerning the LAB microbiota, 444 isolates belonging to Lactobacillus, Enterococcus and Staphylococcus species were isolated. Lactobacillus sakei was the dominant LAB species; interestingly significant genotypic intra-species diversity was observed. Among the Enterococcus species, strains of E. faecium and E. hirae were identified while no E. faecalis were found. S. saprophyticus represented the dominant species of Gram positive, catalase positive cocci although S. xilosus and S. equorum were also identified. The dynamics of the microbial population revealed that no differences in the fermentation and ripening profiles were detected probably due to the high predominance of L. sakei during the entire process. In conclusion, fermented llama sausages displayed good hygienic quality and as expected, L. sakei was the dominating species. The isolated LAB strains will be further analyzed to design a starter culture to shorten the ripening period and improve the quality of the fermented llama sausages. Argentinean Andean region from the Northwestern side of the country exhibits singular environmental conditions limiting agricultural activities as well as the variety of the local diet. Recently, the importance of llama (Lama glama) meat has increased due to its high protein nutritional value and reduced fat and cholesterol contents. Also, the production of fermented llama meat sausages may contribute to the regional economy development. To increase the knowledge on the safety and quality of these fermented sausages the microbial [lactic acid bacteria (LAB) and pathogenic] communities from fermented llama sausages were analyzed by microbiological (specific culture media) and molecular approaches (RAPD-PCR, species-specific PCR and 16s rDNA sequencing). Sausages (meat 72.4%, pork fat 25%, salt 2%, sucrose 1.5%, nitrite 0.025% and seasonings) were produced in a pilot-plant scale in Jujuy (Northwestern Argentina); samples at days 0, 2, 4, 7, 14, 21, 28 and 35 were collected for microbial identification and population dynamics (DGGE) analyses. A pH decrease from 5.6 to 5.0 while the LAB counts varied from 6.5 to 5.0 log CFU/g were determined throughout the whole fermentation-ripening period. Regarding safety, no Staphylococcus aureus, Salmonella and Listeria monocytogenes strains were found while Escherichia coli counts were within the acceptable EFSA standards. Concerning the LAB microbiota, 444 isolates belonging to Lactobacillus, Enterococcus and Staphylococcus species were isolated. Lactobacillus sakei was the dominant LAB species; interestingly significant genotypic intra-species diversity was observed. Among the Enterococcus species, strains of E. faecium and E. hirae were identified while no E. faecalis were found. S. saprophyticus represented the dominant species of Gram positive, catalase positive cocci although S. xilosus and S. equorum were also identified. The dynamics of the microbial population revealed that no differences in the fermentation and ripening profiles were detected probably due to the high predominance of L. sakei during the entire process. In conclusion, fermented llama sausages displayed good hygienic quality and as expected, L. sakei was the dominating species. The isolated LAB strains will be further analyzed to design a starter culture to shorten the ripening period and improve the quality of the fermented llama sausages.