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Aline Lonvaudfunel - One of the best experts on this subject based on the ideXlab platform.
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the Tyrosine Decarboxylase operon of lactobacillus brevis ioeb 9809 characterization and conservation in tyramine producing bacteria
Fems Microbiology Letters, 2003Co-Authors: Patrick Lucas, Monika Coton, Emmanuel Coton, José María Landete, Aline LonvaudfunelAbstract:Bacterial genes of Tyrosine Decarboxylases were recently identified. Here we continued the sequencing of the Tyrosine Decarboxylase locus of Lactobacillus brevis IOEB 9809 and determined a total of 7979 bp. The sequence contained four complete genes encoding a tyrosyl-tRNA synthetase, the Tyrosine Decarboxylase, a probable Tyrosine permease and a Na+/H+ antiporter. Rapid amplification of cDNA ends (RACE) was employed to determine the 5′-end of mRNAs containing the Tyrosine Decarboxylase gene. It was located only 34–35 nucleotides upstream of the start codon, suggesting that the preceding tyrosyl-tRNA synthetase gene was transcribed separately. In contrast, reverse transcription-polymerase chain reactions (RT-PCRs) carried out with primers designed to amplify regions spanning gene junctions showed that some mRNAs contained the four genes. Homology searches revealed similar clusters of four genes in the genome sequences of Enterococcus faecalis and Enterococcus faecium. Phylogenetic analyses supported the hypothesis that these genes evolved all together. These data suggest that bacterial Tyrosine Decarboxylases are encoded in an operon containing four genes.
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purification and partial gene sequence of the Tyrosine Decarboxylase of lactobacillus brevis ioeb 9809
Fems Microbiology Letters, 2002Co-Authors: Patrick Lucas, Aline LonvaudfunelAbstract:Some lactic acid bacteria contain a Tyrosine Decarboxylase (TDC) which converts Tyrosine to tyramine, a biogenic amine frequently encountered in fermented food and wine. Purification and microsequencing of the TDC of Lactobacillus brevis IOEB 9809 allowed us to determine a partial sequence of the TDC gene encoding 264 amino acids of the enzyme. Analysis of this protein sequence revealed typical features of pyridoxal phosphate-dependent amino acid Decarboxylases while not any known Decarboxylase was closely related to the TDC of L. brevis IOEB 9809. In addition, we could detect other L. brevis strains carrying a TDC gene in a rapid assay based on the polymerase chain reaction.
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purification and characterization of Tyrosine Decarboxylase of lactobacillus brevis ioeb 9809 isolated from wine
Fems Microbiology Letters, 2001Co-Authors: Victoria Morenoarribas, Aline LonvaudfunelAbstract:Tyrosine Decarboxylase (EC 4.1.1.25) (TDC) from the wine Lactobacillus brevis IOEB 9809 was purified by a rapid procedure involving anion exchange chromatography, ultrafiltration and hydrophobic interaction chromatography. The protein comprised two subunits of identical molecular mass (approximately 70000 Da). Enzyme activity was dependent on exogenously supplied pyridoxal 5'-phosphate and the enzyme was stable at 4 degrees C in the presence of the coenzyme. Optimum pH for the pure enzyme was 5.0. At this pH, TDC exhibited Michaelis-Menten kinetics (K(m) 0.63 mM, V(max) 998 units) and was highly substrate-specific for L-Tyrosine. Other amino acids and L-DOPA are not converted by the protein. Tyramine acted as a mixed non-competitive inhibitor. Significant similarities in some biochemical properties were observed with the corresponding Decarboxylase enzyme of Streptococcus faecalis, the sole bacterial TDC described to date.
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Tyrosine Decarboxylase activity of lactobacillus brevis ioeb 9809 isolated from wine and l brevis atcc 367
Fems Microbiology Letters, 1999Co-Authors: Victoria Morenoarribas, Aline LonvaudfunelAbstract:Tyramine, a frequent amine in wines, is produced from Tyrosine by the Tyrosine Decarboxylase (TDC) activity of bacteria. The tyramine-producing strain Lactobacillus brevis IOEB 9809 isolated from wine and the reference strain L. brevis ATCC 367 were studied. At the optimum pH, 5.0, Km values of IOEB 9809 and ATCC 367 crude extracts for L-Tyrosine were 0.58 mM and 0.67 mM, and Vmax was higher for the wine strain (115 U) than the ATCC 367 (66 U). TDC exhibited a preference for L-Tyrosine over L-DOPA as substrate. Enzyme activity was pyridoxal-5′-phosphate (PLP)-dependent and it was stabilized by the substrate and coenzyme. In contrast, glycerol and β-mercaptoethanol strongly inhibited TDC. Tyramine competitively inhibited TDC for both strains. Citric acid, lactic acid and ethanol had an inhibitory effect on cells and crude extracts, but none could inhibit TDC at the usual concentrations in wines.
Monika Coton - One of the best experts on this subject based on the ideXlab platform.
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Characterization of the tyramine-producing pathway in Sporolactobacillus sp. P3J
Microbiology, 2011Co-Authors: Monika Coton, Niels L. Mulder, Hein Trip, Juke S Lolkema, Victor Ladero, Maria Fernandez, Miguel A. Alvarez, Emmanuel CotonAbstract:A sporulated lactic acid bacterium (LAB) isolated from cider must was shown to harbour the tdc gene encoding Tyrosine Decarboxylase. The isolate belonged to the Sporolactobacillus genus and may correspond to a novel species. The ability of the tdc-positive strain, Sporolactobacillus sp. strain P3J, to produce tyramine in vitro was demonstrated by using HPLC. A 7535 bp nucleotide sequence harbouring the putative tdc gene was determined. Analysis of the obtained sequence showed that four tyramine production-associated genes [tyrosyl-tRNA synthetase (tyrS), Tyrosine Decarboxylase (tdc), Tyrosine permease (tyrP) and Na+/H+ antiporter (nhaC)] were present and were organized as already described in other tyramine-producing LAB. This operon was surrounded by genes showing the highest identities with mobile elements: a putative phage terminase and a putative transposase (downstream and upstream, respectively), suggesting that the tyramine-forming trait was acquired through horizontal gene transfer. Transcription analyses of the tdc gene cluster suggested that tyrS and nhaC are expressed as monocistronic genes while tdc would be part of a polycistronic mRNA together with tyrP. The presence of Tyrosine in the culture medium induced the expression of all genes except for tyrS. A clear correlation was observed between initial Tyrosine concentration and tyramine production combined with an increase in the final pH reached by the culture. Finally, cloning and expression of the tyrP gene in Lactococcus lactis demonstrated that its product catalyses the exchange of Tyrosine and tyramine. © 2011 SGM.
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multiplex pcr for colony direct detection of gram positive histamine and tyramine producing bacteria
Journal of Microbiological Methods, 2005Co-Authors: Emmanuel Coton, Monika CotonAbstract:Formation of biogenic amines (BA) may occur in fermented foods and beverages due to the amino acid Decarboxylase activities of Gram-positive bacteria. These compounds may cause food poisoning and therefore could imply food exportation problems. A set of consensual primers based on histidine Decarboxylase gene (hdc) sequences of different bacteria was designed for the detection of histamine-producing Gram-positive bacteria. A multiplex PCR based on these hdc primers and recently designed primers targeting the Tyrosine Decarboxylase (tyrdc) gene was created. A third set of primers targeting the 16S rRNA gene of eubacteria was also used as an internal control. This multiplex PCR was performed on extracted DNA as well as directly on cell colonies. The results obtained show that this new molecular tool allowed for the detection of Gram-positive histamine- and/or tyramine-producing bacteria. The use of this molecular tool for early and rapid detection of Gram-positive BA-producing bacteria is of interest in evaluating the potential of cultured indigenous strains to produce biogenic amines in a fermented food product as well as to validate the innocuity of potential starter strains in the food industry.
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Identification of the gene encoding a putative Tyrosine Decarboxylase of Carnobacterium divergens 508. Development of molecular tools for the detection of tyramine-producing bacteria
Food Microbiology, 2004Co-Authors: Monika Coton, Emmanuel Coton, Patrick Lucas, A. LonvaudAbstract:Abstract The gene encoding a putative Tyrosine Decarboxylase (TyrDC) in Carnobacterium divergens 508 was identified by multiple steps of inverse and conventional PCR. The coding region of the tyrdc gene was 1875 bp in size. A putative tyrosyl-tRNA synthetase gene was identified from a partial gene sequence upstream of the tyrdc gene and another partial ORF potentially coding for an amino acid transporter was identified downstream. Comparison to the TyrDC operon of Enterococcus faecalis showed that these three genes are probably part of an operon involved in tyramine production in C. divergens 508. Homology search allowed for the design of a set of consensual primers in the tyrdc gene. These primers were used in PCR experiments and allowed for the detection of tyramine producing bacteria. In the future, these primers could be used for the early detection of potentially tyramine-forming bacteria in food and beverages.
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the Tyrosine Decarboxylase operon of lactobacillus brevis ioeb 9809 characterization and conservation in tyramine producing bacteria
Fems Microbiology Letters, 2003Co-Authors: Patrick Lucas, Monika Coton, Emmanuel Coton, José María Landete, Aline LonvaudfunelAbstract:Bacterial genes of Tyrosine Decarboxylases were recently identified. Here we continued the sequencing of the Tyrosine Decarboxylase locus of Lactobacillus brevis IOEB 9809 and determined a total of 7979 bp. The sequence contained four complete genes encoding a tyrosyl-tRNA synthetase, the Tyrosine Decarboxylase, a probable Tyrosine permease and a Na+/H+ antiporter. Rapid amplification of cDNA ends (RACE) was employed to determine the 5′-end of mRNAs containing the Tyrosine Decarboxylase gene. It was located only 34–35 nucleotides upstream of the start codon, suggesting that the preceding tyrosyl-tRNA synthetase gene was transcribed separately. In contrast, reverse transcription-polymerase chain reactions (RT-PCRs) carried out with primers designed to amplify regions spanning gene junctions showed that some mRNAs contained the four genes. Homology searches revealed similar clusters of four genes in the genome sequences of Enterococcus faecalis and Enterococcus faecium. Phylogenetic analyses supported the hypothesis that these genes evolved all together. These data suggest that bacterial Tyrosine Decarboxylases are encoded in an operon containing four genes.
Patrick Lucas - One of the best experts on this subject based on the ideXlab platform.
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Expression of Lactobacillus brevis IOEB 9809 Tyrosine Decarboxylase and agmatine deiminase genes in wine correlates with substrate availability
Letters in Applied Microbiology, 2011Co-Authors: M. P. Arena, Patrick Lucas, Andrea Romano, V. Capozzi, L. Beneduce, M. Ghariani, F. Grieco, G. SpanoAbstract:AIMS: Lactobacillus brevis IOEB 9809 is able to produce both tyramine and putrescine via Tyrosine Decarboxylase and agmatine deiminase enzymes, respectively, when cultured on synthetic media. The aims of this study were to assess the expression of L. brevis IOEB 9809 tdc and aguA1 genes, during wine fermentation and to evaluate the effect of substrate availability and pH on tdc and aguA1 expression, as well as on biogenic amine production and L. brevis viability. METHODS AND RESULTS: The relative expression of L. brevis IOEB 9809 tdc and aguA1 genes was analysed in wine by quantitative real-time RT-PCR (qRT-PCR) during a period of incubation of 30 days. Cell viability, pH values, putrescine and tyramine concentration were monitored throughout the experiments. CONCLUSIONS: The wine trials indicated that L. brevis IOEB 9809 is able to produce both tyramine and putrescine during wine fermentation. Increased cell viability was also observed in wine supplemented with Tyrosine or agmatine. qRT-PCR analysis suggests a strong influence of substrate availability on the expression of genes coding for Tyrosine Decarboxylase and agmatine deiminase in L. brevis IOEB 9809. Less evident is the relationship between putrescine and tyramine production and tolerance to wine pH. SIGNIFICANCE AND IMPACT OF STUDY: To our knowledge, this study represents the first assessment of relative expression of L. brevis IOEB 9809 genes involved in biogenic amine production in wine. Furthermore, an effect of biogenic amine production on viability of L. brevis during wine fermentation was established.
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Identification of the gene encoding a putative Tyrosine Decarboxylase of Carnobacterium divergens 508. Development of molecular tools for the detection of tyramine-producing bacteria
Food Microbiology, 2004Co-Authors: Monika Coton, Emmanuel Coton, Patrick Lucas, A. LonvaudAbstract:Abstract The gene encoding a putative Tyrosine Decarboxylase (TyrDC) in Carnobacterium divergens 508 was identified by multiple steps of inverse and conventional PCR. The coding region of the tyrdc gene was 1875 bp in size. A putative tyrosyl-tRNA synthetase gene was identified from a partial gene sequence upstream of the tyrdc gene and another partial ORF potentially coding for an amino acid transporter was identified downstream. Comparison to the TyrDC operon of Enterococcus faecalis showed that these three genes are probably part of an operon involved in tyramine production in C. divergens 508. Homology search allowed for the design of a set of consensual primers in the tyrdc gene. These primers were used in PCR experiments and allowed for the detection of tyramine producing bacteria. In the future, these primers could be used for the early detection of potentially tyramine-forming bacteria in food and beverages.
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the Tyrosine Decarboxylase operon of lactobacillus brevis ioeb 9809 characterization and conservation in tyramine producing bacteria
Fems Microbiology Letters, 2003Co-Authors: Patrick Lucas, Monika Coton, Emmanuel Coton, José María Landete, Aline LonvaudfunelAbstract:Bacterial genes of Tyrosine Decarboxylases were recently identified. Here we continued the sequencing of the Tyrosine Decarboxylase locus of Lactobacillus brevis IOEB 9809 and determined a total of 7979 bp. The sequence contained four complete genes encoding a tyrosyl-tRNA synthetase, the Tyrosine Decarboxylase, a probable Tyrosine permease and a Na+/H+ antiporter. Rapid amplification of cDNA ends (RACE) was employed to determine the 5′-end of mRNAs containing the Tyrosine Decarboxylase gene. It was located only 34–35 nucleotides upstream of the start codon, suggesting that the preceding tyrosyl-tRNA synthetase gene was transcribed separately. In contrast, reverse transcription-polymerase chain reactions (RT-PCRs) carried out with primers designed to amplify regions spanning gene junctions showed that some mRNAs contained the four genes. Homology searches revealed similar clusters of four genes in the genome sequences of Enterococcus faecalis and Enterococcus faecium. Phylogenetic analyses supported the hypothesis that these genes evolved all together. These data suggest that bacterial Tyrosine Decarboxylases are encoded in an operon containing four genes.
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purification and partial gene sequence of the Tyrosine Decarboxylase of lactobacillus brevis ioeb 9809
Fems Microbiology Letters, 2002Co-Authors: Patrick Lucas, Aline LonvaudfunelAbstract:Some lactic acid bacteria contain a Tyrosine Decarboxylase (TDC) which converts Tyrosine to tyramine, a biogenic amine frequently encountered in fermented food and wine. Purification and microsequencing of the TDC of Lactobacillus brevis IOEB 9809 allowed us to determine a partial sequence of the TDC gene encoding 264 amino acids of the enzyme. Analysis of this protein sequence revealed typical features of pyridoxal phosphate-dependent amino acid Decarboxylases while not any known Decarboxylase was closely related to the TDC of L. brevis IOEB 9809. In addition, we could detect other L. brevis strains carrying a TDC gene in a rapid assay based on the polymerase chain reaction.
Miguel A. Alvarez - One of the best experts on this subject based on the ideXlab platform.
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the relationship among Tyrosine Decarboxylase and agmatine deiminase pathways in enterococcus faecalis
Frontiers in Microbiology, 2017Co-Authors: Marta Perez, Victor Ladero, Maria Fernandez, Beatriz Del Rio, Begona Redruello, Anne De Jong, Oscar P Kuipers, Jan Kok, Cruz M Martin, Miguel A. AlvarezAbstract:Enterococci are considered mainly responsible for the undesirable accumulation of the biogenic amines (BA) tyramine and putrescine in cheeses. The biosynthesis of tyramine and putrescine has been described as a species trait in Enterococcus faecalis. Tyramine is formed by the decarboxylation of the amino acid Tyrosine, by the Tyrosine Decarboxylase (TDC) route encoded in the tdc cluster. Putrescine is formed from agmatine by the agmatine deiminase (AGDI) pathway encoded in the agdi cluster. These biosynthesis routes have been independently studied, Tyrosine and agmatine transcriptionally regulate the tdc and agdi clusters. The objective of the present work is to study the possible co-regulation among TDC and AGDI pathways in E. faecalis. In the presence of agmatine, a positive correlation between putrescine biosynthesis and the Tyrosine concentration was found. Transcriptome studies showed that Tyrosine induces the transcription of putrescine biosynthesis genes and up-regulates pathways involved in cell growth. The Tyrosine modulation over AGDI route was not observed in the mutant Δtdc strain. Fluorescence analyses using gfp as reporter protein revealed PaguB (the promoter of agdi catabolic genes) was induced by Tyrosine in the wild-type but not in the mutant strain, confirming that tdc cluster was involved in the Tyrosine induction of putrescine biosynthesis. This study also suggests that AguR (the transcriptional regulator of agdi) was implicated in interaction among the two clusters.
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tyramine biosynthesis is transcriptionally induced at low ph and improves the fitness of enterococcus faecalis in acidic environments
Applied Microbiology and Biotechnology, 2015Co-Authors: Marta Perez, Victor Ladero, Marina Callesenriquez, Ingolf F Nes, Maria Cruz Martin, M J Fernandez, Miguel A. AlvarezAbstract:Enterococcus faecalis is a commensal bacterium of the human gut that requires the ability to pass through the stomach and therefore cope with low pH. E. faecalis has also been identified as one of the major tyramine producers in fermented food products, where they also encounter acidic environments. In the present work, we have constructed a non-tyramine-producing mutant to study the role of the tyramine biosynthetic pathway, which converts Tyrosine to tyramine via amino acid decarboxylation. Wild-type strain showed higher survival in a system that mimics gastrointestinal stress, indicating that the tyramine biosynthetic pathway has a role in acid resistance. Transcriptional analyses of the E. faecalis V583 Tyrosine Decarboxylase cluster showed that an acidic pH, together with substrate availability, induces its expression and therefore the production of tyramine. The protective role of the tyramine pathway under acidic conditions appears to be exerted through the maintenance of the cytosolic pH. Tyramine production should be considered important in the adaptability of E. faecalis to acidic environments, such as fermented dairy foods, and to survive passage through the human gastrointestinal tract.
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isolation and characterization of tyramine producing enterococcus faecium strains from red wine
Food Microbiology, 2011Co-Authors: V. Capozzi, Victor Ladero, Maria Fernandez, Miguel A. Alvarez, L. Beneduce, Bach Benoit, Barnavon Laurent, Francesco Grieco, Giuseppe SpanoAbstract:Enterococcus faecium strains were isolated from red wines undergoing malolactic fermentation and identified by comparison of their 16S rDNA gene sequences with those included in the GenEMBL Databases. The Tyrosine Decarboxylase gene was identified in all the strains analysed by PCR using gene-specific primers and the ability to produce tyramine in a synthetic media was analysed by RP-HPLC. Survival of an E. faecium strain was also evaluated in microvinification assays using two different musts with different ethanol concentrations (10% and 12% (v/v)). Tyramine production was monitored during the vinification trials. Our results suggest that E. faecium strains isolated from wine are able to produce tyramine and tolerate wine conditions following a pre-acidic stress.
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Characterization of the tyramine-producing pathway in Sporolactobacillus sp. P3J
Microbiology, 2011Co-Authors: Monika Coton, Niels L. Mulder, Hein Trip, Juke S Lolkema, Victor Ladero, Maria Fernandez, Miguel A. Alvarez, Emmanuel CotonAbstract:A sporulated lactic acid bacterium (LAB) isolated from cider must was shown to harbour the tdc gene encoding Tyrosine Decarboxylase. The isolate belonged to the Sporolactobacillus genus and may correspond to a novel species. The ability of the tdc-positive strain, Sporolactobacillus sp. strain P3J, to produce tyramine in vitro was demonstrated by using HPLC. A 7535 bp nucleotide sequence harbouring the putative tdc gene was determined. Analysis of the obtained sequence showed that four tyramine production-associated genes [tyrosyl-tRNA synthetase (tyrS), Tyrosine Decarboxylase (tdc), Tyrosine permease (tyrP) and Na+/H+ antiporter (nhaC)] were present and were organized as already described in other tyramine-producing LAB. This operon was surrounded by genes showing the highest identities with mobile elements: a putative phage terminase and a putative transposase (downstream and upstream, respectively), suggesting that the tyramine-forming trait was acquired through horizontal gene transfer. Transcription analyses of the tdc gene cluster suggested that tyrS and nhaC are expressed as monocistronic genes while tdc would be part of a polycistronic mRNA together with tyrP. The presence of Tyrosine in the culture medium induced the expression of all genes except for tyrS. A clear correlation was observed between initial Tyrosine concentration and tyramine production combined with an increase in the final pH reached by the culture. Finally, cloning and expression of the tyrP gene in Lactococcus lactis demonstrated that its product catalyses the exchange of Tyrosine and tyramine. © 2011 SGM.
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Tyramine biosynthesis in Enterococcus durans is transcriptionally regulated by the extracellular pH and Tyrosine concentration
Microbial biotechnology, 2009Co-Authors: Maria Fernandez, M. Cruz Martín, Miguel A. AlvarezAbstract:The microbial decarboxylation of some amino acids leads to the undesirable presence of biogenic amines in foods. One of the most abundant and frequent biogenic amines found in fermented foods is tyramine, which is produced by the decarboxylation of Tyrosine. In the present work, transcriptional analysis of tyramine biosynthesis in Enterococcus durans IPLA655, a strain isolated from cheese, was studied. The gene coding for the Tyrosine Decarboxylase (tdcA) and that coding for the Tyrosine‐tyramine antiporter (tyrP) form an operon transcribed from the promoter PtdcA, the expression of which is regulated by the extracellular pH and Tyrosine concentration. Quantification of gene expression during the log phase of growth showed high concentrations of Tyrosine and acidic pH conditions to induce tdcA‐tyrP polycistronic messenger transcription.
Emmanuel Coton - One of the best experts on this subject based on the ideXlab platform.
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Characterization of the tyramine-producing pathway in Sporolactobacillus sp. P3J
Microbiology, 2011Co-Authors: Monika Coton, Niels L. Mulder, Hein Trip, Juke S Lolkema, Victor Ladero, Maria Fernandez, Miguel A. Alvarez, Emmanuel CotonAbstract:A sporulated lactic acid bacterium (LAB) isolated from cider must was shown to harbour the tdc gene encoding Tyrosine Decarboxylase. The isolate belonged to the Sporolactobacillus genus and may correspond to a novel species. The ability of the tdc-positive strain, Sporolactobacillus sp. strain P3J, to produce tyramine in vitro was demonstrated by using HPLC. A 7535 bp nucleotide sequence harbouring the putative tdc gene was determined. Analysis of the obtained sequence showed that four tyramine production-associated genes [tyrosyl-tRNA synthetase (tyrS), Tyrosine Decarboxylase (tdc), Tyrosine permease (tyrP) and Na+/H+ antiporter (nhaC)] were present and were organized as already described in other tyramine-producing LAB. This operon was surrounded by genes showing the highest identities with mobile elements: a putative phage terminase and a putative transposase (downstream and upstream, respectively), suggesting that the tyramine-forming trait was acquired through horizontal gene transfer. Transcription analyses of the tdc gene cluster suggested that tyrS and nhaC are expressed as monocistronic genes while tdc would be part of a polycistronic mRNA together with tyrP. The presence of Tyrosine in the culture medium induced the expression of all genes except for tyrS. A clear correlation was observed between initial Tyrosine concentration and tyramine production combined with an increase in the final pH reached by the culture. Finally, cloning and expression of the tyrP gene in Lactococcus lactis demonstrated that its product catalyses the exchange of Tyrosine and tyramine. © 2011 SGM.
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multiplex pcr for colony direct detection of gram positive histamine and tyramine producing bacteria
Journal of Microbiological Methods, 2005Co-Authors: Emmanuel Coton, Monika CotonAbstract:Formation of biogenic amines (BA) may occur in fermented foods and beverages due to the amino acid Decarboxylase activities of Gram-positive bacteria. These compounds may cause food poisoning and therefore could imply food exportation problems. A set of consensual primers based on histidine Decarboxylase gene (hdc) sequences of different bacteria was designed for the detection of histamine-producing Gram-positive bacteria. A multiplex PCR based on these hdc primers and recently designed primers targeting the Tyrosine Decarboxylase (tyrdc) gene was created. A third set of primers targeting the 16S rRNA gene of eubacteria was also used as an internal control. This multiplex PCR was performed on extracted DNA as well as directly on cell colonies. The results obtained show that this new molecular tool allowed for the detection of Gram-positive histamine- and/or tyramine-producing bacteria. The use of this molecular tool for early and rapid detection of Gram-positive BA-producing bacteria is of interest in evaluating the potential of cultured indigenous strains to produce biogenic amines in a fermented food product as well as to validate the innocuity of potential starter strains in the food industry.
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Identification of the gene encoding a putative Tyrosine Decarboxylase of Carnobacterium divergens 508. Development of molecular tools for the detection of tyramine-producing bacteria
Food Microbiology, 2004Co-Authors: Monika Coton, Emmanuel Coton, Patrick Lucas, A. LonvaudAbstract:Abstract The gene encoding a putative Tyrosine Decarboxylase (TyrDC) in Carnobacterium divergens 508 was identified by multiple steps of inverse and conventional PCR. The coding region of the tyrdc gene was 1875 bp in size. A putative tyrosyl-tRNA synthetase gene was identified from a partial gene sequence upstream of the tyrdc gene and another partial ORF potentially coding for an amino acid transporter was identified downstream. Comparison to the TyrDC operon of Enterococcus faecalis showed that these three genes are probably part of an operon involved in tyramine production in C. divergens 508. Homology search allowed for the design of a set of consensual primers in the tyrdc gene. These primers were used in PCR experiments and allowed for the detection of tyramine producing bacteria. In the future, these primers could be used for the early detection of potentially tyramine-forming bacteria in food and beverages.
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the Tyrosine Decarboxylase operon of lactobacillus brevis ioeb 9809 characterization and conservation in tyramine producing bacteria
Fems Microbiology Letters, 2003Co-Authors: Patrick Lucas, Monika Coton, Emmanuel Coton, José María Landete, Aline LonvaudfunelAbstract:Bacterial genes of Tyrosine Decarboxylases were recently identified. Here we continued the sequencing of the Tyrosine Decarboxylase locus of Lactobacillus brevis IOEB 9809 and determined a total of 7979 bp. The sequence contained four complete genes encoding a tyrosyl-tRNA synthetase, the Tyrosine Decarboxylase, a probable Tyrosine permease and a Na+/H+ antiporter. Rapid amplification of cDNA ends (RACE) was employed to determine the 5′-end of mRNAs containing the Tyrosine Decarboxylase gene. It was located only 34–35 nucleotides upstream of the start codon, suggesting that the preceding tyrosyl-tRNA synthetase gene was transcribed separately. In contrast, reverse transcription-polymerase chain reactions (RT-PCRs) carried out with primers designed to amplify regions spanning gene junctions showed that some mRNAs contained the four genes. Homology searches revealed similar clusters of four genes in the genome sequences of Enterococcus faecalis and Enterococcus faecium. Phylogenetic analyses supported the hypothesis that these genes evolved all together. These data suggest that bacterial Tyrosine Decarboxylases are encoded in an operon containing four genes.
