title: Increased expression of clp genes in Lactobacillus delbrueckii UFV H2b20 exposed to acid stress and bile salts.
abstract: The ability to survive in harsh environments is an important criterion to select potential probiotics strains. The objective of this study was to identify and carry out phylogenetic and expression analysis by quantitative real-time PCR of the clpP, clpE, clpL and clpX genes in the probiotic strain Lactobacillus delbrueckii UFV H2b20 exposed to the conditions prevailing in the gastrointestinal tract (GIT). Phylogenetic trees reconstructed by Bayesian inference showed that the L. delbrueckii UFV H2b20 clpP, clpL and clpE genes and the ones from L. delbrueckii ATCC 11842 were grouped. The exposure of cells to MRS broth of pH 3.5 for 30 and 60 min resulted in an increased expression of the four genes. Exposure of the L. delbrueckii UFV H2b20 cells for 30 and 60 min to MRS broth containing 0.1% bile salts increased the expression of the clpP and clpE genes, while the expression level of the clpL and clpX genes increased only after 30 min of exposure. The involvement of the studied genes in the responses to acid stress and bile salts suggests a possible central role of these genes in the survival of L. delbrueckii UFV H2b20 during the passage through the GIT, a characteristic necessary for probiotic strains.
authors: Departamento de Microbiologia, Universidade Federal de Viçosa, Instituto de Biotecnologia Aplicada à Agropecuária-BIOAGRO, Viçosa, MG 36571-000, Brazil.
authors: A B
authors: AB
authors: Ferreira
authors: Departamento Básico - Área de Saúde, Universidade Federal de Juiz de Fora, Governador Valadares, MG 35020-220, Brazil.
authors: M N V
authors: MNV
authors: De Oliveira
authors: Departamento de Microbiologia, Universidade Federal de Viçosa, Instituto de Biotecnologia Aplicada à Agropecuária-BIOAGRO, Viçosa, MG 36571-000, Brazil.
authors: F S
authors: FS
authors: Freitas
authors: Departamento de Microbiologia, Universidade Federal de Viçosa, Instituto de Biotecnologia Aplicada à Agropecuária-BIOAGRO, Viçosa, MG 36571-000, Brazil.
authors: P
authors: P
authors: Alfenas-Zerbini
authors: Departamento de Nutrição, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Diamantina, MG 39100-000, Brazil.
authors: D F
authors: DF
authors: Da Silva
authors: Departamento de Microbiologia, Universidade Federal de Viçosa, Instituto de Biotecnologia Aplicada à Agropecuária-BIOAGRO, Viçosa, MG 36571-000, Brazil.
authors: M V
authors: MV
authors: De Queiroz
authors: Departamento de Microbiologia, Universidade Federal de Viçosa, Instituto de Biotecnologia Aplicada à Agropecuária-BIOAGRO, Viçosa, MG 36571-000, Brazil.
authors: A C
authors: AC
authors: Borges
authors: Departamento de Microbiologia, Universidade Federal de Viçosa, Instituto de Biotecnologia Aplicada à Agropecuária-BIOAGRO, Viçosa, MG 36571-000, Brazil.
authors: C A
authors: CA
authors: De Moraes
mesh_terms: D000143:Acids / Q000633:toxicity*; D001647:Bile Acids and Salts / Q000633:toxicity*; D049071:Endopeptidase Clp / Q000096:biosynthesis* / Q000235:genetics; D020869:Gene Expression Profiling; D006360:Heat-Shock Proteins / Q000096:biosynthesis* / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D048668:Lactobacillus delbrueckii / Q000187:drug effects* / Q000201:enzymology* / Q000502:physiology; D060888:Real-Time Polymerase Chain Reaction; D013312:Stress, Physiological; D013997:Time Factors
chemical_list: D000143:Acids; D001647:Bile Acids and Salts; D006360:Heat-Shock Proteins; D049071:Endopeptidase Clp
keywords: molecular phylogeny; probiotics; quantitative real-time PCR; stress response