A5035294360- Probiotics and Fermented Foods
- Microbial Metabolic Engineering and Bioproduction
- Bacterial Genetics and Biotechnology
- RNA and protein synthesis mechanisms
- Microbial Metabolites in Food Biotechnology
- Bacteriophages and microbial interactions
- Genomics and Phylogenetic Studies
- GABA and Rice Research
- Amino Acid Enzymes and Metabolism
- RNA Research and Splicing
- Microbial Metabolism and Applications
- RNA modifications and cancer
- Gut microbiota and health
- Polyamine Metabolism and Applications
- Gene Regulatory Network Analysis
- Enzyme Structure and Function
- Enzyme Production and Characterization
- Biochemical effects in animals
- Meat and Animal Product Quality
- Protein Hydrolysis and Bioactive Peptides
- Biofuel production and bioconversion
- Biochemical and Structural Characterization
- Pharmacological Effects of Natural Compounds
- Microbial Community Ecology and Physiology
- Botanical Research and Chemistry
Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement
2020-2025
Université de Toulouse
2015-2025
Centre National de la Recherche Scientifique
2015-2025
Institut National des Sciences Appliquées de Toulouse
2013-2025
Biotechnology Institute
2014-2022
Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés
2011-2020
Université Toulouse III - Paul Sabatier
2008-2016
Institut National Polytechnique de Toulouse
2015
Laboratoire de Microbiologie et Génétique Moléculaires
2013
Institut National de la Recherche Agronomique
2005-2013
During batch growth of Lactococcus lactis subsp. NCDO 2118 on various sugars, the shift from homolactic to mixed-acid metabolism was directly dependent sugar consumption rate. This orientation pyruvate related flux-controlling activity glyceraldehyde-3-phosphate dehydrogenase under conditions high glycolytic flux glucose due NADH/NAD+ ratio. The limitation at level led an increase in pool concentrations both and dihydroxyacetone-phosphate inhibition formate lyase activity. Under such...
Abstract Irritable bowel syndrome (IBS) is a multifactorial disorder of the gut‐brain axis, characterized by visceral hypersensitivity (VH). Psychobiotics, through GABA synthesis, are good candidates to alleviate gastrointestinal discomfort. Here, we analyzed GABA‐producer Lactococcus lactis CNCM I‐5388 as an active‐enzyme postbiotic relieve VH mediated psychological stress. L. was inactivated ethanol while maintaining its glutamate decarboxylase (GAD) activity. This EtOH‐treated nonviable...
Growth of Corynebacterium glutamicum on fructose was significantly less than that obtained glucose, despite similar rates substrate uptake. This in part due to the production overflow metabolites (dihydroxyacetone and lactate) but also increased CO 2 during growth fructose. These differences carbon‐metabolite accumulation are indicative a different pattern carbon‐flux distribution through central metabolic pathways. glucose has been previously shown involve high flux (> 50 % total...
Abstract Microorganisms extensively reorganize gene expression to adjust growth rate changes in conditions. At the genomic scale, we measured contribution of both transcription and transcript stability regulating messenger RNA (mRNA) concentration Escherichia coli. Transcriptional control was dominant regulatory process. Between rates 0.10 0.63 h−1, there a generic increase bulk mRNA transcription. However, many transcripts became less stable median half-life decreased from 4.2 2.8 min. This...
Changing mRNA stability is a major post-transcriptional way of controlling gene expression, particularly in newly encountered conditions. As the concentration result an equilibrium between transcription and degradation, it generally assumed that at constant transcription, any change consequence stabilization or destabilization. However, literature reports many cases opposite variations bacteria. Here, we analyzed causal link two phylogenetically distant bacteria Escherichia coli Lactococcus...
ABSTRACT Staphylococcus aureus is responsible for numerous food poisonings due to the production of enterotoxins by strains contaminating foodstuffs, especially dairy products. Several parameters, including interaction with antagonistic flora such as Lactococcus lactis , a lactic acid bacterium widely used in industry, can modulate S. proliferation and virulence expression. We developed dedicated microarray investigate effect L. on staphylococcal gene expression mixed cultures. This was...
Bacterial adaptation involves extensive cellular reorganization. In particular, growth rate adjustments are associated with substantial modifications of gene expression and mRNA abundance. this work we aimed to assess the role degradation during such variations. A genome-wide transcriptomic-based method was used determine half-lives. The model bacterium Lactococcus lactis different rates were studied in continuous cultures under isoleucine-limitation batch isoleucine starvation. During...
Lactococcus lactis subsp. strain A12 was isolated from sourdough. Combined genomic, transcriptomic, and phenotypic analyses were performed to understand its survival capacity in the complex sourdough ecosystem role microbial community. The genome sequence comparison of with IL1403 (a derivative an industrial dairy strain) revealed 78 strain-specific regions representing 23% total size. Most genes involved carbohydrate metabolism are potentially required for persistence Phenotype microarray,...
Lactococcus lactis NCDO 2118 was previously selected for its ability to decarboxylate glutamate γ-aminobutyric acid (GABA), an interesting nutritional supplement able improve mood and relaxation. Amino decarboxylation is generally considered as among the biochemical systems allowing lactic bacteria counteracting acidic stress obtaining metabolic energy. These strategies also include arginine deiminase pathway malolactic fermentation but little known about their possible interactions of with...
Abstract Bacterial adaptation requires large-scale regulation of gene expression. We have performed a genome-wide analysis the Csr system, which regulates many important cellular functions. The system is involved in post-transcriptional regulation, but role transcriptional has also been suggested. Two proteins, an RNA-binding protein CsrA and atypical signaling CsrD, participate system. Genome-wide transcript stabilities levels were compared wildtype E. coli (MG1655) isogenic mutant strains...
Summary The reason for RNase E attachment to the inner membrane is largely unknown. To understand cell biology of RNA degradation, we have characterized a strain expressing lacking site (cytoplasmic E). Genome‐wide data show global slowdown in mRNA degradation. There no correlation between stabilization and function or cellular location encoded proteins. activity cRNase comparable wild‐type enzyme vitro , but mutant protein unstable vivo . Autoregulation synthesis compensates instability....
The alpha-acetolactate decarboxylase gene aldB is clustered with the genes for branched-chain amino acids (BCAA) in Lactococcus lactis subsp. lactis. It can be transcribed BCAA under isoleucine regulation or independently of synthesis control its own promoter. product responsible leucine sensibility valine starvation. In presence more than 10 microM leucine, produced by biosynthetic acetohydroxy acid synthase IlvBN transformed to acetoin AldB and, consequently, not available synthesis. also...
The physiological behavior of Corynebacterium glutamicum in glucose-limited chemostat cultures was examined from both growth kinetics and enzymatic viewpoints. Metabolic fluxes within the central metabolism were calculated analyzed relation to specific enzyme activities. At high rates, incomplete glucose removal observed, this attributed rate-limiting capacity phosphotransferase system transporter probable contribution a low-affinity permease uptake mechanism. improved biomass yield observed...
The metabolic characteristics of Lactococcus lactis IL1403 were examined on two different growth media with respect to the physiological response sugars, glucose and galactose. Analysis specific rates indicated that despite significant variations in both sugar consumption, homolactic fermentation was maintained for all cultures due low concentration either pyruvate-formate lyase or alcohol dehydrogenase. When ionophore monensin added medium, flux through glycolysis not increased, suggesting...
The growth of two strains Lactococcus lactis subsp. from vegetable (NCDO 2118) and dairy origin (IL 1403) were compared on various culture media. Both grew more rapidly a complex organic medium than defined synthetic medium. best was obtained under nitrogen gas phase. single omission technique applied to each component non‐optimized in order determine the true nutritional requirements. Requirements for macro‐elements, oligo‐elements, bases vitamins identical strains. As expected, strain seen...
The physiological behaviour of Lactococcus lactis subsp. cremoris MG 1363 was characterized in continuous culture under various acidic conditions (pH 4·7–6·6). Biomass yield diminished cultures with low pH and the energy dedicated to maintenance increased due organic acid inhibition cytoplasmic acidification. Under such conditions, specific rate glucose consumption by bacterium increased, thereby enhancing supply. This acceleration glycolysis regulated both an increase concentrations...
The stability of mRNA was investigated for the first time at genomic scale during carbon starvation adaptation Lactococcus lactis IL1403. In exponential phase, half-lives were correlated positively to open reading frame length. A polypurine sequence, AGGAG, identified as a putative 5'-stabilizer and inverted repeated sequences 3'-destabilizer. These original findings suggested that multiple pathways degradation should coexist: internal cleavage, endonuclease cleavage initiated 5'-end,...
Adaptation of Lactococcus lactis towards progressive carbon starvation is mediated by three different types transcriptomic responses: (i) global responses, i.e., general decreases functions linked to bacterial growth and lack induction the stress response; (ii) specific responses functionally related glucose exhaustion, underexpression central metabolism genes, alternative sugar transport metabolism, arginine deiminase pathway; (iii) other never described previously during starvation.
ABSTRACT Lactococcus lactis is used extensively for the production of various cheeses. At every stage cheese fabrication, L. has to face several stress-generating conditions that result from its own modification environment as well externally imposed conditions. We present here first in situ global gene expression profile cheeses made milk concentrated by ultrafiltration (UF-cheeses), a key economical model. The transcriptomic response was analyzed directly matrix, starting early 2 h and...
Abstract Background In bacteria, the weak correlations at genome scale between mRNA and protein levels suggest that not all mRNAs are translated with same efficiency. To experimentally explore translational level regulation systemic level, detailed status (translatome) of was measured in model bacterium Lactococcus lactis exponential phase growth. Results demonstrated only part entire population each species engaged translation. For transcripts involved translation, polysome size reached a...