Genetic and Physiological Responses of Bifidobacterium animalis subsp. lactis to Hydrogen Peroxide Stress

Genetic and Physiological Responses of <i>Bifidobacterium animalis</i> subsp. <i>lactis</i> to Hydrogen Peroxide Stress

Polyphasic taxonomic analysis of Bifidobacterium animalis and Bifidobacterium lactis reveals relatedness at the subspecies level: reclassification of Bifidobacterium animalis as Bifidobacterium animalis subsp. animalis subsp. nov. and Bifidobacterium lactis as Bifidobacterium animalis subsp. lactis subsp. nov.

The taxonomic standing of Bifidobacterium lactis and Bifidobacterium animalis was investigated using a polyphasic approach. Sixteen representatives of both taxa were found to be phenotypically similar and shared more than 70% DNA-DNA relatedness (76-100%), which reinforces the conclusions of previous studies in which B. lactis and B. animalis were considered to be one single species. However, t...

Genetic basis of tetracycline resistance in Bifidobacterium animalis subsp. lactis.

All strains of Bifidobacterium animalis subsp. lactis described to date show medium level resistance to tetracycline. Screening of 26 strains from a variety of sources revealed the presence of tet(W) in all isolates. A transposase gene upstream of tet(W) was found in all strains, and both genes were cotranscribed in strain IPLAIC4. Mutants with increased tetracycline resistance as well as tetra...

Adaptation and response of Bifidobacterium animalis subsp. lactis to bile: a proteomic and physiological approach.

Bile salts are natural detergents that facilitate the digestion and absorption of the hydrophobic components of the diet. However, their amphiphilic nature makes them very inhibitory for bacteria and strongly influences bacterial survival in the gastrointestinal tract. Adaptation to and tolerance of bile stress is therefore crucial for the persistence of bacteria in the human colonic niche. Bif...

Molecular clues to understand the aerotolerance phenotype of Bifidobacterium animalis subsp. lactis.

Oxygen is one of the abiotic factors negatively affecting the survival of Bifidobacterium strains used as probiotics, mainly due to the induction of lethal oxidative damage. Aerobic conditions are present during the process of manufacture and storage of functional foods, and aerotolerance is a desired trait for bifidobacteria intended for use in industry. In the present study, the molecular res...