Person:
Bravo Vázquez, Daniel Antonio

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First Name
Daniel Antonio
Last Name
Bravo Vázquez
URI
https://hdl.handle.net/20.500.14352/86409
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Biológicas
Department
Genética, Fisiología y Microbiología
Area
Microbiología
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2017 - 20183
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Author: Landete, José × End date: 2019 ×

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Now showing 1 - 3 of 3
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    Genetic engineering as a powerful tool to improve probiotic strains
    (Biotechnology and Genetic Engineering Reviews, 2017) Landete, José; Bravo Vázquez, Daniel Antonio
    Over the last decade, there has been increasing interest in the use of probiotic microorganisms. However, certain doubts have arisen around probiotics, because of the beneficial effects of these microorganisms are not clear yet, and in many occasions those beneficial effects have not been proven. Therefore, it would be of interest if these probiotic strains were able to acquire new attributes to allow them improve and increase their beneficial characteristics. Genetic engineering can be used for human applications; for instance, the resistance to antibiotics is removed and the probiotic bacteria are modified in its own DNA. This process can be achieved by (1) the use of food-grade vectors derived from lactic acid bacteria and/or bifidobacteria cryptic plasmids, (2) the genes integration or deletion in the chromosome of the probiotic strain, by site-specific recombination using the attP/integrase system, or by homologous recombination, using either suicide vectors, (3) using the clustered regularly interspaced short palindromic repeats (CRISPR) and the CRISPR-associated (Cas) nuclease. Through genetic engineering, the knowledge of probiotic strains as well as its use could be improved, and the doubts about probiotics could be crumped
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    Phytoestrogen metabolism by lactic acid bacteria: Enterolignan production by Lactobacillus salivarius and Lactobacillus gasseri strains
    (Journal of Functional Foods, 2017) Peirotén, Ángela ; Álvarez, Inmaculada ; Landete, José ; Bravo Vázquez, Daniel Antonio
    Phytoestrogens are plant polyphenols similar to human estrogens. Isoflavones, ellagitanins, and lignans are metabolized by intestinal bacteria into equol, urolithins, and enterolignans, respectively, which are more bioavailable and bioactive, having beneficial effects on health. In this paper, we analysed the production of equol, 5-hydroxy-equol, enterodiol and enterolactone by 70 strains of Lactobacillus, Lactococcus and Enterococcus. Enterodiol and enterolactone production was found in Lactobacillus salivarius INIA P183, Lb. salivarius INIA P448 and Lactobacillus gasseri INIA P508, in levels around 46 mM and 6 mM respectively. However, we did not find neither equol nor 5-hydroxy-equol producing strains. Furthermore, analysis of the ellagic acid metabolism was extended to a total of 138 lactic acid bacteria strains, although none of them produced urolithins. This is the first time that simultaneous production of enterolactone and enterodiol is described in bacteria with probiotic potential, open their possible application in functional foods.
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    Influence of different lignan compounds on enterolignan production by Bifidobacterium and Lactobacillus strains
    (International Journal of Food Microbiology, 2018) Peroitén, Angela; Gaya, Pilar; Álvarez, Inmaculada; Bravo Vázquez, Daniel Antonio; Landete, José
    Enterolignans, i.e. enterodiol and enterolactone, are polyphenols derived from the microbial metabolism of dietary lignans. They are considered phytoestrogens because of their estrogenic/antiestrogenic activity, which confers them benefits to human health when they reach sufficient levels in plasma. Hence, there is a great interest in studying the bacteria involved in enterolignan production. In the present study, three bifidobacterial strains (Bifidobacterium bifidum INIA P466, Bifidobacterium catenulatum INIA P732 and Bifidobacterium pseudolongum INIA P2) were found capable of producing low levels of enterodiol (2–11 μM) from lignan extracts; while another one (Bifidobacterium pseudocatenulatum INIA P946) was found to produce an important increment of the lignan secoisolariciresinol (SECO). Subsequently, the three enterodiol-producing bifidobacteria and another three Lactobacillus strains previously identified as enterolignans producers (Lactobacillus gasseri INIA P508, Lactobacillus salivarius INIA P448 and Lb. salivarius INIA P183), were tested on pure lignans yielding both enterodiol and enterolactone from secoisolariciresinol (SECO), while they did not metabolised the other lignan tested (i.e. matairesinol). B. catenulatum INIA P732 and Lb. gasseri INIA P508 were the strains that transformed the greatest percentage of SECO, yielding enterolactone concentrations above 2 mM. In addition, the formation of the intermediate compound dihydroxyenterodiol was observed as part of SECO transformation by all the strains. In this work, we have demonstrated for the first time how strains of Bifidobacterium and Lactobacillus are capable of carrying out the complete enterolignan metabolism, transforming a purified lignan (SECO) into enterodiol and enterolactone. The isolation and characterization of bacteria able to metabolize lignans and produce enterolignans, especially belonging to Bifidobacterium and Lactobacillus genera, is of biotechnological interest, because of their potential application in functional foods and as probiotics.