Caracterização e identificação de Enterococcus spp. isolados do fermento endógeno utilizado na fabricação do queijo Minas artesanal da região da Canastra, Minas Gerais

• Autor(a) principal: Araújo, Tatiane Ferreira
• Data de Publicação: 2008
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2855
• topic: Bactérias láticas; Queijo artesanal; Enterococcus; Lactic bacteria; Artisan Minas cheese; Enterococcus; CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS::CIENCIA DE ALIMENTOS

This work aimed to characterize and to identify Gram positive cocos, negative catalase, isolated from endogenous yeast employed in the manufacture of the Canastra cheese. This cheese is produced in the Canastra region, Minas Gerais, with raw bovine milk and with the addition of endogenous cultures known as pingo (drop). This microbiota is rather diversified, what makes it possible the identification of a number of microbial groups in their composition, and guarantees a product with unique sensorial properties. Among the 106 isolates obtained from the Kenner Fecal (KF) agar of cheeses manufactured in eight cheese producing units from Medeiros city, Minas Gerais, 79 were classified as presumptively pertaining to the Enterococcus spp. genus due to the results of the traditional biochemical tests as hydrolysis of arginine, growth at 4 and 6.5% NaCl, 10 and 45 ºC, pH 9.6 and aesculin Bile, as well as the evaluation for Gram coloration and catalase. The results indicated fifteen different phenotypical profiles, in which the isolates were grouped. Only four isolates were identified as typical Enterococcus for having presented positive results for all the tests. Forty two isolates presented 85.71% similarity with Enterococcus faecalis and Enterococcus faecium species groups. After that, forty five were selected, isolated, and submitted to the characterization with aid of the API 20 STREP® kit. The results obtained with the use of the kit did not identify them in a satisfactory way, classifying the isolates as Aerococcus viridans 1, Aerococcus viridans 2, Aerococcus viridans 3 and Enterococcus avium. However, in general, the classification was given as weak discrimination . These isolates were submitted to the molecular identification through the Polymerase chain reaction (PCR) technique. In this way, nine isolates were classified as Enterococcus spp. And two classified as Enterococcus faecium. These results diverge of those ones mentioned by the classic methodology and API 20 STREP® kit. This work is a continuity of an extensive research of identification and characterization of the endogenous yeast employed in the manufacture of the Canastra cheese. The correct identification of the organisms present in this microbiota make it possible, later, to relate the role of these microorganisms in the development of the sensorial characteristics and quality of the artisan Minas cheese.