Comportamento de Lactobacillus delbrueckii UFV H2b20 sob condições prevalecentes no trato gastrointestinal humano

• Ano de defesa: 2012
• Autor(a) principal: Conceição, Lisiane Lopes da
• Orientador(a): Moraes, Célia Alencar de
• Banca de defesa: Peluzio, Maria do Carmo Gouveia , Zerbini, Poliane Alfenas
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Microbiologia Agrícola
• Departamento: Associações micorrízicas; Bactérias láticas e probióticos; Biologia molecular de fungos de interesse
• País: BR
• Palavras-chave em Português: L. delbrueckii UFV H2b20; Estresse; Trato gastrointestinal humano
• Palavras-chave em Inglês: L. delbrueckii UFV H2B20; Stress; Human gastrointestinal tract
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOSSANIDADE::MICROBIOLOGIA AGRICOLA
• Link de acesso: http://locus.ufv.br/handle/123456789/5351

Bacteria of the genus Lactobacillus are inhabit the human gastrointestinal tract (GHT) and species such as Lactobacillus delbrueckii UFV H2B20, isolated from feces of infant exclusively fed breast milk, have physiological characteristics, technology, immunological and genetic desirable and necessary to probiose. The objective of this work was to study the tolerance of L. delbrueckii UFV H2b20 to gastric juice and simulated intestinal when incorporated in a food matrix, fermented milk, and also the expression of the gene encoding the fbpA, binding protein fibronectin, involved in adhesion to the human gastrointestinal tract. The results showed that L. delbrueckii UFV H2b20 is able to maintain its viability at levels above 108 UFC.mL-1 after 28 days of storage. When subjected to the conditions prevailing in TGH found that the food matrix evaluated, the fermented milk, confer protection. After the fourteenth day of the experiment, no significant survival in simulated intestinal juice. The fbpA gene was identified by PCR and sequencing. This gene is clustered with the orthologs of probiotic bacteria. However, exposure of cells of L. delbrueckii UFV H2B20 incorporated in fermented milk, for 240 minutes to the conditions prevailing in TGH caused reduced expression of this gene, detected by RT-PCR. Confirmation of the involvement of this gene under stress conditions, in adherence to the TGH compartments remains dependent on studies with mutant bacteria.