Comparative proteomic analysis of Lactobacillus plantarum for the identification of key proteins in bile tolerance

<p>Abstract</p> <p>Background</p> <p>Lactic acid bacteria are commonly marketed as probiotics based on their putative or proven health-promoting effects. These effects are known to be strain specific but the underlying molecular mechanisms remain poorly understood. Therefore, unravelling the determinants behind probiotic features is of particular interest since it would help select strains that stand the best chance of success in clinical trials. Bile tolerance is one of the most crucial properties as it determines the ability of bacteria to survive in the small intestine, and consequently their capacity to play their functional role as probiotics. In this context, the objective of this study was to investigate the natural protein diversity within the <it>Lactobacillus plantarum </it>species with relation to bile tolerance, using comparative proteomics.</p> <p>Results</p> <p>Bile tolerance properties of nine <it>L. plantarum </it>strains were studied <it>in vitro</it>. Three of them presenting different bile tolerance levels were selected for comparative proteomic analysis: <it>L. plantarum </it>299 V (resistant), <it>L. plantarum </it>LC 804 (intermediate) and <it>L. plantarum </it>LC 56 (sensitive). Qualitative and quantitative differences in proteomes were analyzed using two-dimensional electrophoresis (2-DE), tryptic digestion, liquid chromatography-mass spectrometry analysis and database search for protein identification. Among the proteins correlated with differences in the 2-DE patterns of the bacterial strains, 15 have previously been reported to be involved in bile tolerance processes. The effect of a bile exposure on these patterns was investigated, which led to the identification of six proteins that may be key in the bile salt response and adaptation in <it>L. plantarum</it>: two glutathione reductases involved in protection against oxidative injury caused by bile salts, a cyclopropane-fatty-acyl-phospholipid synthase implicated in maintenance of cell envelope integrity, a bile salt hydrolase, an ABC transporter and a F0F1-ATP synthase which participate in the active removal of bile-related stress factors.</p> <p>Conclusions</p> <p>These results showed that comparative proteomic analysis can help understand the differential bacterial properties of lactobacilli. In the field of probiotic studies, characteristic proteomic profiles can be identified for individual properties that may serve as bacterial biomarkers for the preliminary selection of strains with the best probiotic potential.</p

Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe

Use of proteomic analysis in the characterization of bacteria of probiotic interest

La réglementation européenne 1924/2006 exige que toute allégation santé soit étayée par des preuves scientifiques fiables de nature clinique. Force est de constater que la majorité des fabricants de probiotiques actuellement sur le marché ne fournissent pas ces preuves, dans la mesure où les études cliniques sont onéreuses et où il y a un manque de méthodes satisfaisantes et abordables facilitant la sélection préliminaire des souches les plus prometteuses. Dans ce contexte, l'objectif de ce travail de thèse a été de développer une méthode analytique globale, basée sur la protéomique, pour différencier les souches probiotiques des souches sans bénéfice pour l'hôte, et pour essayer de comprendre certains mécanismes d'interaction probiotiques/hôte. Parmi la large gamme de propriétés et d'activités des bactéries probiotiques, nous nous sommes intéressés à la résistance aux conditions gastro-intestinales, à la capacité d'adhésion au mucus, et aux activités hypocholestérolémiante et immunomodulatrice de souches de Lactobacillus casei et de Lactobacillus plantarum. Cette approche a permis d'identifier des profils protéomiques particuliers susceptibles de constituer des marqueurs bactériens de propriétés et d'activités probiotiques.The 1924/2006 European regulation requires health claims to be substantiated with relevant clinical data. There is no denying that most of the manufacturers of currently marketed probiotics do not provide such substantiation, inasmuch as clinical studies are expensive and there is a lack for satisfactory and affordable methods facilitating the preliminary selection of the most promising strains. In this context, this thesis aimed at developing a global analytical method, based on proteomics, to differentiate probiotic strains from strains with no advantage for the host, and to try to understand some of the probiotic/host interaction mechanisms. Among the variety of properties and activities of probiotic bacteria, we focused on the resistance to gastro-intestinal conditions, the adhesion to mucus, and the hypocholesterolemic and immunomodulatory activities of Lactobacillus casei and Lactobacillus plantarum strains. This approach enabled to identify particular proteomic profiles likely to represent bacterial markers of probiotic properties and activities

Use of proteomic analysis in the characterization of bacteria of probiotic interest

La réglementation européenne 1924/2006 exige que toute allégation santé soit étayée par des preuves scientifiques fiables de nature clinique. Force est de constater que la majorité des fabricants de probiotiques actuellement sur le marché ne fournissent pas ces preuves, dans la mesure où les études cliniques sont onéreuses et où il y a un manque de méthodes satisfaisantes et abordables facilitant la sélection préliminaire des souches les plus prometteuses. Dans ce contexte, l'objectif de ce travail de thèse a été de développer une méthode analytique globale, basée sur la protéomique, pour différencier les souches probiotiques des souches sans bénéfice pour l'hôte, et pour essayer de comprendre certains mécanismes d'interaction probiotiques/hôte. Parmi la large gamme de propriétés et d'activités des bactéries probiotiques, nous nous sommes intéressés à la résistance aux conditions gastro-intestinales, à la capacité d'adhésion au mucus, et aux activités hypocholestérolémiante et immunomodulatrice de souches de Lactobacillus casei et de Lactobacillus plantarum. Cette approche a permis d'identifier des profils protéomiques particuliers susceptibles de constituer des marqueurs bactériens de propriétés et d'activités probiotiques.The 1924/2006 European regulation requires health claims to be substantiated with relevant clinical data. There is no denying that most of the manufacturers of currently marketed probiotics do not provide such substantiation, inasmuch as clinical studies are expensive and there is a lack for satisfactory and affordable methods facilitating the preliminary selection of the most promising strains. In this context, this thesis aimed at developing a global analytical method, based on proteomics, to differentiate probiotic strains from strains with no advantage for the host, and to try to understand some of the probiotic/host interaction mechanisms. Among the variety of properties and activities of probiotic bacteria, we focused on the resistance to gastro-intestinal conditions, the adhesion to mucus, and the hypocholesterolemic and immunomodulatory activities of Lactobacillus casei and Lactobacillus plantarum strains. This approach enabled to identify particular proteomic profiles likely to represent bacterial markers of probiotic properties and activities

Utilisation de l analyse protéomique dans la caractérisation des bactéries d intérêt probiotique

La réglementation européenne 1924/2006 exige que toute allégation santé soit étayée par des preuves scientifiques fiables de nature clinique. Force est de constater que la majorité des fabricants de probiotiques actuellement sur le marché ne fournissent pas ces preuves, dans la mesure où les études cliniques sont onéreuses et où il y a un manque de méthodes satisfaisantes et abordables facilitant la sélection préliminaire des souches les plus prometteuses. Dans ce contexte, l objectif de ce travail de thèse a été de développer une méthode analytique globale, basée sur la protéomique, pour différencier les souches probiotiques des souches sans bénéfice pour l hôte, et pour essayer de comprendre certains mécanismes d interaction probiotiques/hôte. Parmi la large gamme de propriétés et d activités des bactéries probiotiques, nous nous sommes intéressés à la résistance aux conditions gastro-intestinales, à la capacité d adhésion au mucus, et aux activités hypocholestérolémiante et immunomodulatrice de souches de Lactobacillus casei et de Lactobacillus plantarum. Cette approche a permis d identifier des profils protéomiques particuliers susceptibles de constituer des marqueurs bactériens de propriétés et d activités probiotiques.The 1924/2006 European regulation requires health claims to be substantiated with relevant clinical data. There is no denying that most of the manufacturers of currently marketed probiotics do not provide such substantiation, inasmuch as clinical studies are expensive and there is a lack for satisfactory and affordable methods facilitating the preliminary selection of the most promising strains. In this context, this thesis aimed at developing a global analytical method, based on proteomics, to differentiate probiotic strains from strains with no advantage for the host, and to try to understand some of the probiotic/host interaction mechanisms. Among the variety of properties and activities of probiotic bacteria, we focused on the resistance to gastro-intestinal conditions, the adhesion to mucus, and the hypocholesterolemic and immunomodulatory activities of Lactobacillus casei and Lactobacillus plantarum strains. This approach enabled to identify particular proteomic profiles likely to represent bacterial markers of probiotic properties and activities.STRASBOURG-Sc. et Techniques (674822102) / SudocSudocFranceF

Quantitative proton nuclear magnetic resonance analysis (q 1H NMR) of various aqueous extracts of thermally processed (“roasted”) coffee (Coffea arabica L.) beans

National audienc

Proton quantitative nuclear magnetic resonance analysis (1H q NMR) of various extracts of raw and thermally processed (“roasted”) coffee (Coffea arabica L.) beans. Influence of the extraction process

National audienc

Proton quantitative nuclear magnetic resonance analysis (1H q-NMR) of various extracts of raw and thermally processed (“Roasted”) coffee (Coffea arabica L.) beans: Influence of the extraction process

International audienc

Combined microplate-ABTS and HPLC-ABTS analysis of tomato and pepper extracts reveals synergetic and antagonist effects of their lipophilic antioxidative components

International audienceThe antioxidant capacity of 9 pure lipophilic compounds was examined by microplate-ABTS and HPLCABTS,using similar experimental conditions. Results obtained showed that HPLC-ABTS method can beused for a rapid determination of individual antioxidant capacity of compounds in standard solutionsor complex mixtures. The application of both methods to real lipophilic extracts from tomato (Solanumlycopersicum L.), green and red peppers (Capsicum annuum) reveals possible interactions betweenantioxidants. Thus, synthetic mixtures of two compounds identified in tomato and peppers weremeasured using microplate-ABTS and HPLC-ABTS. Synergistic effects were observed between(b-carotene-capsanthin) (1:9) and (1:1), (a-tocopherol-capsanthin) (1:9), (lutein-lycopene) (9:1)and (capsanthin-d-tocopherol) (9:1). On the contrary, antagonistic effects were observed for(lutein-d-tocopherol) and (a-tocopherol-d-tocopherol). The interactions observed with two-compoundmixtures are not systematically observed in the natural lipophilic extracts from tomato, green and redpeppers, probably since extracts are more complex and are susceptible to cause interferences

Identification of markers of thermal processing ("roasting") in aqueous extracts of <em>Coffea arabica</em> L. seeds through NMR fingerprinting and chemometrics

International audienceRoasting of Coffea arabica L. seeds gives rise to chemical reactions that produce more than 800 compounds, some being responsible for the desired organoleptic properties for which the beverage called “coffee” is known. In the industry, the “roasting profile,” that is, the times and temperatures applied, is key to influence the composition of roasted coffee beans and the flavour of the beverage made from them. The impact of roasting on the chemical composition of coffee has been the subject of numerous studies, including by nuclear magnetic resonance (NMR) spectroscopy. However, the roasting equipment and profiles applied in these studies are often far from real industrial conditions. In this work, the effects of two critical technological parameters of the roasting process, namely, the “development time” (the period of time after the “first crack,” a characteristic noise due to seed disruption) and the final roasting temperature on coffee extracts, were investigated. Seeds were roasted at pilot scale according to 13 industrial roasting profiles and extracted in D2O. The extracts were analysed by 1H NMR experiments. The NMR spectra were compared using (a) quantitative analysis of main signals by successive orders of magnitude and (b) chemometric tools (principal component analysis, partial least squares and sparse‐orthogonal partial least squares analysis). This allowed to identify compounds, which may serve as markers of roasting and showed that changes in chemical composition can be detected even for slight change in final temperature (~1°C) or in total roasting time (~25 s)