Maître de Conférences
Faculté des Sciences et Technologies - Nancy
Université de Lorraine
+33 (0)3 72 74 56 82 | emeline.roux@univ-lorraine.fr
BMC Genomics, 23, pp. 210.
Roux, É., Nicolas, A., Valence, F., Siekaniec, G., Chuat, V., Nicolas, J., Le Loir, Y., Guédon, E.
Microorganisms, 9 (6), pp. 1113-1113.
Uriot, O., Kebouchi, M., Lorson-Dalibard, É., Galia, W., Denis, S., Chalançon, S., Hafeez, Z., Roux, É., Genay, M., Blanquet-Diot, S., Dary-Mourot, A.
Despite promising health effects, the probiotic status of Streptococcus thermophilus, a lactic
acid bacterium widely used in dairy industry, requires further documentation of its physiological
status during human gastrointestinal passage. This study aimed to apply recombinant-based in vivo
technology (R-IVET) to identify genes triggered in a S. thermophilus LMD-9 reference strain under
simulated digestive conditions. First, the R-IVET chromosomal cassette and plasmid genomic library
were designed to positively select activated genes. Second, recombinant clones were introduced
into complementary models mimicking the human gut, the Netherlands Organization for Applied
Scientific Research (TNO) gastrointestinal model imitating the human stomach and small intestine,
the Caco-2 TC7 cell line as a model of intestinal epithelium, and anaerobic batch cultures of human
feces as a colon model. All inserts of activated clones displayed a promoter activity that differed
from one digestive condition to another. Our results also showed that S. thermophilus adapted its
metabolism to stressful conditions found in the gastric and colonic competitive environment and
modified its surface proteins during adhesion to Caco-2 TC7 cells. Activated genes were investigated
in a collection of S. thermophilus strains showing various resistance levels to gastrointestinal stresses,
a first stage in the identification of gut resistance markers and a key step in probiotic selection.
Microbiology Resource Announcements, 9 (11), e00129-20
Devaere, M., Boukthir, S., Moullec, S., Roux, É., Lavenier, D., Faili, A., Kayal, S.
The frequency of infections due to Streptococcus pyogenes M/emm89 strains is increasing, presumably due to the emergence of a genetically distinct clone. We sequenced two emm89 strains isolated in Brittany, France, in 2009 and 2010 from invasive and noninvasive infections, respectively. Both strains belong to a newly emerged emm89 clade 3 clone.
Applied Microbiology and Biotechnology, 103 (6), pp. 2759–2771.
Khaldi, T.E.M., Kebouchi, M., Soligot-Hognon, C., Gomri, M.A., Kharroub, K., Le Roux, Y., Roux, É.
In this study, Streptococcus macedonicus (S. macedonicus) strains were identified from Algerian traditional fermented milks (Lben and Rayeb). Important prerequisites of probiotic interest such as acidity, bile salts tolerance, and adhesion ability to epithelial cells were investigated. A combination of phenotypic (ability to grow on Bile Esculin Azide medium, BEA; on high salt content medium NaCl 6.5%; on alkaline medium pH 9.6) and genotypic approaches (16S rRNA, ITS genes sequencing and MLST technique) allowed to identify four genetically distinct strains of S. macedonicus. These four strains and two references, Streptococcus thermophilus LMD-9 and Lactobacillus rhamnosus GG (LGG), were tested for their capacity to survive at low pH values, and at different concentrations of an equimolar bile salts mixture (BSM). Two different cell lines, Caco-2 TC7 and HT29-MTX, were used for the adhesion study. The results show that S. macedonicus strains selected constitute a distinct genetic entity from the Greek strain S. macedonicus ACA-DC-198. They were able to survive up to pH 3 and could tolerate high concentrations of bile salts (10 mM), unlike LMD-9 and LGG strains. Our strains also display in vitro adhesion similar to the LGG strain on Caco-2 TC7 and higher adhesion than the LMD-9 strain to Caco-2 TC7 and HT29-MTX cell models. This first characterization allows considering S. macedonicus as a potential candidate for possible probiotic effects that need to be investigated.
Food Research International, 86, pp. 34-45.
Jameh, N., Galia, W., Awussi, A. A., Roux, É., Genay, M., Perrin, C., Dary, A.
In silico analysis of the genome of Streptococcus thermophilus LMD-9 revealed that this strain has a potential new peptide/nickel ABC transporter. We named this system OTS for Oligopeptide Transporter of S. thermophilus. It is composed of a peptide/nickel binding protein OtsA, two permeases OtsB and OtsC and a double ATPase OtsD. This system was presumably acquired by horizontal transfer from Actinobacteria or distant species like Lactococcus raffinolactis or Enterococcus asini may be via an intermediate like Lactococcus lactis or its ancestor. RT-PCR experiments proved that OTS gene cluster is transcribed and that at least the otsB, otsC, and otsD genes constitute an operon. A mutant LMD-9?ots, partially deleted for the otsA and otsB genes was constructed. Growth of LMD-9 and LMD-9?ots strains was monitored in the presence of different nitrogen sources and in the presence of urea and nickel. Results revealed that OTS is not implicated in nickel transport, but constitutes a new characterized transporter of peptides of small size, possibly di- and tripeptides in S. thermophilus.
LWT - Food Science and Technology, 70 (1), pp. 78-87.
Junjua, M., Kechaou, N., Chain, F., Awussi, A. A., Roussel, Y., Perrin, C., Roux, É., Langella, P., Bermúdez-Humarán, L.G., Le Roux, Y., Chatel, J.-M., Dary, A.
In spite of its contribution to health benefits of yogurt, probiotic properties of Streptococcus thermophilus remain less explored. Hence, we evaluated the capacities of 30 strains of different origins, to resist the stresses prevailing in digestive tracts, of adhering to the mucus producing HT29-MTX cells, as well as their anti-inflammatory properties. First, on the basis of results obtained by multilocus sequence typing, two very closely related groups were distinguished phylogenetically. However, it appeared that in spite of this phylogenetic proximity, resistance to low pH, bile salts and H2O2 and their capacities of adhesion highly varied from one strain to another. Furthermore, most of the strains reduced the production of the pro-inflammatory interleukin IL-8 after co-incubation with HT-29 cells, while they induced production of the anti-inflammatory interleukin IL-10, when incubated with Peripheral Blood Mononuclear Cells. On the basis of ratio of synthesis of IL-10 and of IL-12, currently used to evaluate the anti-inflammatory potential of a probiotic bacterium, three strains appeared to display a strong and promising in vitro anti-inflammatory potential, suggesting that they could be appropriate for elaborating anti-inflammatory functional fermented foods. Finally, the Principal Component Analysis method enabled us to cluster strains into 6 classes displaying distinct phenotypic properties.
Applied Microbiology and Biotechnology, 100 (8), pp. 3667-3679.
Kebouchi, M., Galia, W., Genay, M., Soligot-Hognon, C., Lecomte, X., Awussi, A. A., Perrin, C., Roux, É., Dary, A., Le Roux, Y.
Streptococcus thermophilus (ST) is a lactic acid
bacterium widely used in dairy industry and displays several
properties which could be beneficial for host. The objective of
this study was to investigate, in vitro, the implication of
sortase A (SrtA) and sortase-dependent proteins (SDPs) in
the adhesion of ST LMD-9 strain to intestinal epithelial cells
(IECs) and resistance to bile salt mixture (BSM;
taurocholoate, deoxycholate, and cholate). The effect of mutations
in prtS (protease), mucBP (MUCin-Binding Protein),
and srtA genes in ST LMD-9 in these mechanisms were examined.
The HT29-MTX, HT29-CL.16E, and Caco-2 TC7
cell lines were used. HT29-MTX and HT29-CL.16E cells
express different mucins found in the gastro intestinal tract;
whereas, Caco-2 TC7 express cell surface proteins found in
the small intestine. All mutants showed different adhesion
profiles depending on cell lines. The mutation in genes srtA
and mucBP leads to a significant decrease in LMD-9 adhesion
capacity to Caco-2 TC7 cells. A mutation in mucBP gene has
also shown a significant decrease inLMD-9 adhesion capacity
to HT29-CL.16E cells. However, no difference was observed
using HT29-MTX cells. Furthermore, ST LMD-9 and srtA
mutant were resistant to BSM up to 3 mM. Contrariwise, no
viable bacteria were detected for prtS and mucBP mutants at
this concentration. Two conclusions could be drawn. First,
SDPs could be involved in the LMD-9 adhesion depending
on the cell lines indicating the importance of eukaryotic-cell
surface components in adherence. Second, SDPs could contribute
to resistance to bile salts probably by maintaining the
cell membrane integrity.
International Dairy Journal, 38 (2), pp. 104-115.
Chang, O.-K., Roux, É., Awussi, A. A., Miclo, L., Jardin, J., Jameh, N., Dary, A., Humbert, G., Perrin, C.
Bioactive peptides can be produced from milk proteins in fermented products by proteases of lactic acid
bacteria. The cell envelope protease (PrtS) of Streptococcus thermophilus is anchored at the cellwall, but we
recently discovered that the 4F44 strain produces a soluble form that can be recovered in medium supernatant.
This workwas aimed at optimising the production of bioactive peptides from bovine caseins. By
growing S. thermophilus 4F44 in the newly designed YLUNi medium, a high quantity of the soluble form of
PrtS could be produced that could be directly used as the proteolytic agent on sodium caseinate. Peptide
production was monitored by reverse phase-high performance liquid chromatography and tandem mass
spectrometry; of 247 peptides identified, 143 were derived from beta-casein. Twenty-two peptides, already
reported in the literature as bioactive, include ACE-inhibitory, antioxidant, immunomodulating, or antibacterial
peptides; addition of such peptides could improve the health benefits of dairy products.
Food Research International, 63 (A), pp. 71-80.
Hafeez, Z., Cakir-Kiefer, C., Roux, É., Perrin, C., Miclo, L., Dary, A.
Besides their basic nutritional role, dietary proteins contain bioactive peptides which are encrypted in their sequence and may modulate different body functions such as digestive, cardiovascular, immune and nervous systems, and therefore contribute in maintaining consumer health. Currently, milk proteins are considered to be the major source of bioactive peptides. The occurrence of these peptides has already been reported in fermented milk products such as yogurt, sour milk or kefir and some of them have been shown to confer health benefits. This review focuses on different strategies that could be employed to enhance the production of bioactive peptides from the milk proteins that will be consequently used to functionalize the fermented milk products. Three types of strategies are developed. The first exploits the proteolytic system of lactic acid bacteria (LAB) or food grade enzymes or combination of both to release the functional peptides from the milk proteins directly in the fermented milk products. The second concerns the supplementation of the fermented milk products with the bioactive peptides obtained outside of the product through the hydrolysis of the purified proteins by the same enzyme sources. Finally, the last consists in the production of the bioactive peptides, initially identified from the milk-proteins, by microorganisms using recombinant DNA technology.
International Dairy Journal, 23 (2), pp. 91-98.
Chang, O.K., Perrin, C., Galia, W., Saulnier, F., Miclo, L., Roux, E., Driou, A., Humbert, G., Dary, A.
PrtS is the sole cell envelope protease (CEP) characterized in Streptococcus thermophilus. It is believed that it is anchored to the cell wall by sortase A (SrtA) through the LPXTG motif present at its C-terminus. Two soluble proteases corresponding to PrtS in its proenzyme and mature form were detected in the supernatant of S. thermophilus strain 4F44. In this strain, 60% of the PrtS molecules are anchored to the cell wall and 40% released in the medium. Such a release might result from a partial deficiency in the strain 4F44 of SrtA, even if its sequence slightly differs from that of S. thermophilus strain LMD-9, in which PrtS is anchored. Indeed, the presence of an intact LPXTG motif at the C-terminus of the released proteases showed that the linking process driven by SrtA did not occur and these proteases were not released by proteolysis after their anchoring.
Journal of Agricultural and Food Chemistry, 60 (2), pp 554-565.
Miclo, L., Roux, E., Genay, M., Brusseaux, E., Poirson, C., Jameh, N., Perrin, C., Dary, A.
Milk proteins contain numerous potential bioactive peptides, which may be released by digestive proteases or by the proteolytic system of lactic acid bacteria during food processing. The capacity of Streptococcus thermophilus to generate peptides, especially bioactive peptides, from bovine caseins was investigated. Strains expressing various levels of the Cell Envelope Proteinase, PrtS, were incubated either with αs1-, αs2- or β-casein. Analysis of the supernatants by LC-ESI-MS/MS showed that the β-casein was preferentially hydrolyzed first, followed by αs2-casein and then αs1-casein. Numbers and types of peptides released were strain-dependent. Hydrolysis appeared to be linked with the accessibility of different casein regions by protease. Analysis of bonds hydrolyzed in the region 1-23 of αs1-casein suggests that PrtS is at least in part responsible for the peptide production. Finally, among the generated peptides, 13 peptides from β-casein, 5 from αs2-casein and 2 from αs1-casein have been reported as bioactive, 15 of them being angiotensin-converting enzyme inhibitors.
Plant Physiology and Biochemistry 42 (6), pp. 501-509.
Jolivet, P., Roux, E., D'Andrea, S., Davanture, M., Negroni, L., Zivy, M., Chardot, T.
Applied and Environmental Microbiology 70 (7), pp. 3918-3924.
Mlicková, K., Roux, E., Athenstaedt, K., D'Andrea, S., Daum, G., Chardot, T., Nicaud, J.-M.
Oleosins of Arabidopsis thaliana: expression in Escherichia coli, purification, and functional properties
Journal of Agricultural and Food Chemistry 52 (16), pp. 5245-5249.
Roux, E., Baumberger, S., Axelos, M.A.V., Chardot, T.
Inhibitory effect of unheated and heated D-glucose, D-fructose and L-cysteine solutions and Maillard reaction product model systems on polyphenoloxidase from apple. I. Enzymatic browning and enzyme activity inhibition using spectrophotometric and polarographic methods.
Food Chemistry, 81 (1), PP. 35-50.
BILLAUD, C., ROUX, E., BRUN-MÉRIMÉE, S., MARASCHIN, C., NICOLAS, J.
Food Chemistry 81 (1), pp. 51-60.
Roux, E., Billaud, C., Maraschin, C., Brun-Mérimée, S., Nicolas, J.
1er Congrès International de Technologies Alimentaires et Contrôle Qualité des Aliments, 25-27 avril, Djerba, Tunisie
Nasri, W., Jrad, Z., Roux, É., Perrin, C., Girardet, J.-M., Arroum, S., Khorchani, T., El Hatmi, H.
8th NIZO dairy conference, 11-13 Septembre, Papendal, Pays-Bas.
Roux, É., Miclo, L., Chang, O.-K., Humbert, G., Dary, A., Perrin, C.
19e Colloque du Club des Bactéries Lactiques, 16-18 Octobre, Bordeaux, France.
Awussi, A. A., Roux, É., Chang, O.-K., Humbert, G., Dary, A., Perrin, C.
18e Colloque du Club des Bactéries Lactiques, 22-24 mai, Clermont-Ferrand, France
Chang, O.-K., Perrin, C., Roux, É., Miclo, L., Humbert, G., Dary, A.
17e Colloque du Club des Bactéries Lactiques (CBL), 27-29 octobre, Nancy, France
Dary, A., Miclo, L., Cakir-Kiefer, C., Roux, E., Humbert, G., Driou, A., Perrin, C.
17e Colloque du Club des Bactéries Lactiques (CBL), 27-29 octobre, Nancy, France
Jameh, N., Perrin, C., Carré, J., Galia, W., Roux, E., Dary, A.
17e Colloque du Club des Bactéries Lactiques (CBL), 27-29 octobre, Nancy, France
Roux, E., Miclo, L., Brusseaux, E., Poirson, C., Perrin, C., Dary, A.
Yeast discrimination: evaluation of molecular typing tools for yeast strain discrimination and homogeneity checking.
30th EBC congress, 14-19 mai, Prague, République Tchèque.
Daubos N., Roux E., Kobi D., Gutfreund L. et Didierjean L.,
Interactions à une interface des oléosines avec des phospholipides et des triglycérides
1er congrès de lipidomique du Groupe d’Etude et de Recherche sur les Lipides et les lipoprotéines, septembre, Paris, France
Roux E., Baumberger S., Axelos M., Chardot T.
Inhibitory effect of Maillard reaction products prepared from glucose or fructose with L-cysteine on enzymatic browning and activity of polyphenoloxidase from apple and tyrosinase from mushroom
Polyphenols Communications, XXIth International Conference on Polyphenols 9-12 Septembre, Marrakech, Maroc.
Billaud, S., Roux, E., Corbin, A., Nicolas, J.
Behaviour of oleosins at oil/water or air/water interfaces
43rd international conference on the bioscience of lipids, 11-14 Septembre, Graz, Autriche.
Roux, E., Baumberger, S., Chardot, T.