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Bradley S. Moore - One of the best experts on this subject based on the ideXlab platform.
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inactivation complementation and heterologous expression of encp a novel bacterial phenylalanine ammonia lyase gene
Journal of Biological Chemistry, 2002Co-Authors: Longkuan Xiang, Bradley S. MooreAbstract:Abstract The enzyme phenylalanine ammonia-lyase, which catalyzes the nonoxidative deamination ofl-phenylalanine to trans-cinnamic acid, is ubiquitously distributed in plants. We now report its characterization for the first time in a bacterium. The phenylalanine ammonia-lyase homologous gene encP from the “Streptomyces maritimus” enterocin biosynthetic gene cluster was functionally characterized and shown to encode the first enzyme in the pathway to the enterocin polyketide synthase starter unit benzoyl-coenzyme A. The disruption of the encP gene completely inhibited the production of cinnamate and enterocin, whereas complementation of the mutant with benzoyl-coenzyme A pathway intermediates or with the wild-type gene encP restored the formation of the benzoate-primed polyketide antibiotic enterocin. Heterologous expression of the encP gene under the control of the ermE* promoter in Streptomyces coelicolor furthermore led to the production of cinnamic acid in the fermented cultures, confirming that the encP gene indeed encodes a novel bacterial phenylalanine ammonia-lyase.
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inactivation complementation and heterologous expression of encp a novel bacterial phenylalanine ammonia lyase gene
Journal of Biological Chemistry, 2002Co-Authors: Longkuan Xiang, Bradley S. MooreAbstract:Abstract The enzyme phenylalanine ammonia-lyase, which catalyzes the nonoxidative deamination ofl-phenylalanine to trans-cinnamic acid, is ubiquitously distributed in plants. We now report its characterization for the first time in a bacterium. The phenylalanine ammonia-lyase homologous gene encP from the “Streptomyces maritimus” enterocin biosynthetic gene cluster was functionally characterized and shown to encode the first enzyme in the pathway to the enterocin polyketide synthase starter unit benzoyl-coenzyme A. The disruption of the encP gene completely inhibited the production of cinnamate and enterocin, whereas complementation of the mutant with benzoyl-coenzyme A pathway intermediates or with the wild-type gene encP restored the formation of the benzoate-primed polyketide antibiotic enterocin. Heterologous expression of the encP gene under the control of the ermE* promoter in Streptomyces coelicolor furthermore led to the production of cinnamic acid in the fermented cultures, confirming that the encP gene indeed encodes a novel bacterial phenylalanine ammonia-lyase.
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inactivation complementation and heterologous expression ofencp a novel bacterial phenylalanine ammonia lyase gene
Journal of Biological Chemistry, 2002Co-Authors: Longkuan Xiang, Bradley S. MooreAbstract:Abstract The enzyme phenylalanine ammonia-lyase, which catalyzes the nonoxidative deamination ofl-phenylalanine to trans-cinnamic acid, is ubiquitously distributed in plants. We now report its characterization for the first time in a bacterium. The phenylalanine ammonia-lyase homologous gene encP from the “Streptomyces maritimus” enterocin biosynthetic gene cluster was functionally characterized and shown to encode the first enzyme in the pathway to the enterocin polyketide synthase starter unit benzoyl-coenzyme A. The disruption of the encP gene completely inhibited the production of cinnamate and enterocin, whereas complementation of the mutant with benzoyl-coenzyme A pathway intermediates or with the wild-type gene encP restored the formation of the benzoate-primed polyketide antibiotic enterocin. Heterologous expression of the encP gene under the control of the ermE* promoter in Streptomyces coelicolor furthermore led to the production of cinnamic acid in the fermented cultures, confirming that the encP gene indeed encodes a novel bacterial phenylalanine ammonia-lyase.
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mutational analysis of the enterocin favorskii biosynthetic rearrangement
Organic Letters, 2002Co-Authors: Longkuan Xiang, John A Kalaitzis, George Nilsen, Li Chen, Bradley S. MooreAbstract:A mutational analysis of the enterocin biosynthesis genes revealed that the putative oxygenase and the methyltransferase gene products EncM and EncK, respectively, jointly catalyze a biosynthetic Favorskii-like rearrangement. Inactivation of either gene terminated enterocin production and caused the accumulation of four nonrearranged, nonmethylated polyketides. The structure elucidation of the new wailupemycins E−G is reported.
Longkuan Xiang - One of the best experts on this subject based on the ideXlab platform.
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inactivation complementation and heterologous expression of encp a novel bacterial phenylalanine ammonia lyase gene
Journal of Biological Chemistry, 2002Co-Authors: Longkuan Xiang, Bradley S. MooreAbstract:Abstract The enzyme phenylalanine ammonia-lyase, which catalyzes the nonoxidative deamination ofl-phenylalanine to trans-cinnamic acid, is ubiquitously distributed in plants. We now report its characterization for the first time in a bacterium. The phenylalanine ammonia-lyase homologous gene encP from the “Streptomyces maritimus” enterocin biosynthetic gene cluster was functionally characterized and shown to encode the first enzyme in the pathway to the enterocin polyketide synthase starter unit benzoyl-coenzyme A. The disruption of the encP gene completely inhibited the production of cinnamate and enterocin, whereas complementation of the mutant with benzoyl-coenzyme A pathway intermediates or with the wild-type gene encP restored the formation of the benzoate-primed polyketide antibiotic enterocin. Heterologous expression of the encP gene under the control of the ermE* promoter in Streptomyces coelicolor furthermore led to the production of cinnamic acid in the fermented cultures, confirming that the encP gene indeed encodes a novel bacterial phenylalanine ammonia-lyase.
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inactivation complementation and heterologous expression of encp a novel bacterial phenylalanine ammonia lyase gene
Journal of Biological Chemistry, 2002Co-Authors: Longkuan Xiang, Bradley S. MooreAbstract:Abstract The enzyme phenylalanine ammonia-lyase, which catalyzes the nonoxidative deamination ofl-phenylalanine to trans-cinnamic acid, is ubiquitously distributed in plants. We now report its characterization for the first time in a bacterium. The phenylalanine ammonia-lyase homologous gene encP from the “Streptomyces maritimus” enterocin biosynthetic gene cluster was functionally characterized and shown to encode the first enzyme in the pathway to the enterocin polyketide synthase starter unit benzoyl-coenzyme A. The disruption of the encP gene completely inhibited the production of cinnamate and enterocin, whereas complementation of the mutant with benzoyl-coenzyme A pathway intermediates or with the wild-type gene encP restored the formation of the benzoate-primed polyketide antibiotic enterocin. Heterologous expression of the encP gene under the control of the ermE* promoter in Streptomyces coelicolor furthermore led to the production of cinnamic acid in the fermented cultures, confirming that the encP gene indeed encodes a novel bacterial phenylalanine ammonia-lyase.
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inactivation complementation and heterologous expression ofencp a novel bacterial phenylalanine ammonia lyase gene
Journal of Biological Chemistry, 2002Co-Authors: Longkuan Xiang, Bradley S. MooreAbstract:Abstract The enzyme phenylalanine ammonia-lyase, which catalyzes the nonoxidative deamination ofl-phenylalanine to trans-cinnamic acid, is ubiquitously distributed in plants. We now report its characterization for the first time in a bacterium. The phenylalanine ammonia-lyase homologous gene encP from the “Streptomyces maritimus” enterocin biosynthetic gene cluster was functionally characterized and shown to encode the first enzyme in the pathway to the enterocin polyketide synthase starter unit benzoyl-coenzyme A. The disruption of the encP gene completely inhibited the production of cinnamate and enterocin, whereas complementation of the mutant with benzoyl-coenzyme A pathway intermediates or with the wild-type gene encP restored the formation of the benzoate-primed polyketide antibiotic enterocin. Heterologous expression of the encP gene under the control of the ermE* promoter in Streptomyces coelicolor furthermore led to the production of cinnamic acid in the fermented cultures, confirming that the encP gene indeed encodes a novel bacterial phenylalanine ammonia-lyase.
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mutational analysis of the enterocin favorskii biosynthetic rearrangement
Organic Letters, 2002Co-Authors: Longkuan Xiang, John A Kalaitzis, George Nilsen, Li Chen, Bradley S. MooreAbstract:A mutational analysis of the enterocin biosynthesis genes revealed that the putative oxygenase and the methyltransferase gene products EncM and EncK, respectively, jointly catalyze a biosynthetic Favorskii-like rearrangement. Inactivation of either gene terminated enterocin production and caused the accumulation of four nonrearranged, nonmethylated polyketides. The structure elucidation of the new wailupemycins E−G is reported.
Pablo E. Hernández - One of the best experts on this subject based on the ideXlab platform.
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The Potential of Class II Bacteriocins to Modify Gut Microbiota to Improve Host Health
PLOS ONE, 2016Co-Authors: Özgün C. O. Umu, Pablo E. Hernández, Christine Bäuerl, Marije Oostindjer, Phillip B. Pope, Gaspar Pérez-martínez, Dzung B. DiepAbstract:Production of bacteriocins is a potential probiotic feature of many lactic acid bacteria (LAB) as it can help prevent the growth of pathogens in gut environments. However, knowledge on bacteriocin producers in situ and their function in the gut of healthy animals is still limited. In this study, we investigated five bacteriocin-producing strains of LAB and their isogenic non-producing mutants for probiotic values. The LAB bacteriocins, sakacin A (SakA), pediocin PA-1 (PedPA-1), Enterocins P, Q and L50 (Enterocins), plantaricins EF and JK (plantaricins) and garvicin ML (GarML), are all class II bacteriocins, but they differ greatly from each other in terms of inhibition spectrum and physicochemical properties. The strains were supplemented to mice through drinking water and changes on the gut microbiota composition were interpreted using 16S rRNA gene analysis. In general, we observed that overall structure of the gut microbiota remained largely unaffected by the treatments. However, at lower taxonomic levels, some transient but advantageous changes were observed. Some potentially problematic bacteria were inhibited (e.g., Staphylococcus by Enterocins, Enterococcaceae by GarML, and Clostridium by plantaricins) and the proportion of LAB was increased in the presence of SakA-, plantaricins- and GarML-producing bacteria. Moreover, the treatment with GarML-producing bacteria co-occurred with decreased triglyceride levels in the host mice. Taken together, our results indicate that several of these bacteriocin producers have potential probiotic properties at diverse levels as they promote favorable changes in the host without major disturbance in gut microbiota, which is important for normal gut functioning.
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identification of bacteriocin genes in enterococci isolated from game animals and saltwater fish
Journal of Food Protection, 2011Co-Authors: Tereza Almeida, Andreia Brandao, Estefania Munozatienza, Luis M. Cintas, Carmen Herranz, Gilberto Igrejas, Alexandre Gonçalves, Carmen Torres, Pablo E. Hernández, Patrícia PoetaAbstract:Bacteriocins produced by enterococci, referred to as Enterocins, possess great interest for their potential use as biopreservatives in food and feed, as well as alternative antimicrobials in humans...
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identification of bacteriocin genes in enterococci isolated from game animals and saltwater fish
Journal of Food Protection, 2011Co-Authors: Tereza Almeida, Andreia Brandao, Estefania Munozatienza, Luis M. Cintas, Carmen Herranz, Gilberto Igrejas, Alexandre Gonçalves, Carmen Torres, Pablo E. Hernández, Patrícia PoetaAbstract:Bacteriocins produced by enterococci, referred to as Enterocins, possess great interest for their potential use as biopreservatives in food and feed, as well as alternative antimicrobials in humans and animals. In this context, the aim of the present study was to determine the antimicrobial activity and the presence of bacteriocin structural genes in fecal enterococcal isolates from animal origins. Evaluation of the direct antimicrobial activity of 253 isolates from wild boars (Sus scrofa, n = 69), mullets (Liza ramada, n = 117), and partridges (Perdix perdix, n = 67) against eight indicator bacterial strains (including Listeria monocytogenes, Pediococcus pentosaceus, and Enterococcus spp.) showed that 177 (70%) exerted antimicrobial activity against at least one indicator microorganism. From these isolates, 123 were further selected on the basis of their inhibition group, and 81 were found to be producers of bacteriocins active against Listeria monocytogenes. Analysis of the presence of enterocin structural genes in a subset of 36 isolates showed that 70% harbored one or more of the evaluated genes, those of enterocin P and hiracin JM79 being the most prevalent. These results show that wild animals constitute an appropriate source for the isolation of bacteriocinogenic enterococci.
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antimicrobial activity of enterococcus faecium l50 a strain producing Enterocins l50 l50a and l50b p and q against beer spoilage lactic acid bacteria in broth wort hopped and unhopped and alcoholic and non alcoholic lager beers
International Journal of Food Microbiology, 2008Co-Authors: Antonio Basanta, Carmen Herranz, Pablo E. Hernández, Jorge Sanchez, Beatriz Gomezsala, Luis M. CintasAbstract:Abstract Enterococcus faecium L50 produces enterocin L50 (L50A and L50B) (EntL50, EntL50A and EntL50B), enterocin P (EntP) and enterocin Q (EntQ) and displays a broad antimicrobial spectrum against the most relevant beer-spoilage lactic acid bacteria (LAB) (i.e., Lactobacillus brevis and Pediococcus damnosus), which is mainly due to the production of EntL50 (EntL50A and EntL50B). Bacteriocin assays using in vitro-synthesized EntL50 (EntL50A and EntL50B) showed that both individual peptides possess antimicrobial activity on their own, EntL50A being the most active, but when the two peptides were combined a synergistic effect was observed. The only virulence genes detected in E. faecium L50 were efaAfm (cell wall adhesin) and ccf (sex pheromone), and this strain was susceptible to most clinically relevant antibiotics. E. faecium L50 survived but did not grow nor showed antimicrobial activity in hopped and unhopped wort, and alcoholic (1 and 5% ethanol, v/v) and non-alcoholic (0% ethanol, v/v) commercial lager beers. However, when unhopped wort was supplemented with 50% (v/v) MRS broth, E. faecium L50 grew and exerted antimicrobial activity similarly as in MRS broth. The Enterocins produced by this strain were bactericidal (5 log decrease) against P. damnosus and Lb. brevis in a dose- and substrate-dependent manner when challenged in MRS broth, wort (hopped and unhopped), and alcoholic (1 and 5% ethanol, v/v) and non-alcoholic (0% ethanol, v/v) lager beers at 32 °C, and no bacterial resistances were detected even after incubation for 6–15 days. The Enterocins in wort and lager beer (5% ethanol, v/v) withstood the heat treatments commonly employed in the brewing industry during mashing, wort boiling, fermentation, and pasteurization, and retained most of their antimicrobial activity in lager beer (5% ethanol, v/v) after long-term storage at 8 and 25 °C.
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biochemical and genetic evidence that enterococcus faecium l50 produces Enterocins l50a and l50b the sec dependent enterocin p and a novel bacteriocin secreted without an n terminal extension termed enterocin q
Journal of Bacteriology, 2000Co-Authors: Luis M. Cintas, Carmen Herranz, P Casaus, Helge Holo, Leiv Sigve Havarstein, Pablo E. HernándezAbstract:Enterococcus faecium L50 grown at 16 to 32°C produces enterocin L50 (EntL50), consisting of EntL50A and EntL50B, two unmodified non-pediocin-like peptides synthesized without an N-terminal leader sequence or signal peptide. However, the bacteriocin activity found in the cell-free culture supernatants following growth at higher temperatures (37 to 47°C) is not due to EntL50. A purification procedure including cation-exchange, hydrophobic interaction, and reverse-phase liquid chromatography has shown that the antimicrobial activity is due to two different bacteriocins. Amino acid sequences obtained by Edman degradation and DNA sequencing analyses revealed that one is identical to the sec-dependent pediocin-like enterocin P produced by E. faecium P13 (L. M. Cintas, P. Casaus, L. S. Havarstein, P. E. Hernandez, and I. F. Nes, Appl. Environ. Microbiol. 63:4321–4330, 1997) and the other is a novel unmodified non-pediocin-like bacteriocin termed enterocin Q (EntQ), with a molecular mass of 3,980. DNA sequencing analysis of a 963-bp region of E. faecium L50 containing the enterocin P structural gene (entP) and the putative immunity protein gene (entiP) reveals a genetic organization identical to that previously found in E. faecium P13. DNA sequencing analysis of a 1,448-bp region identified two consecutive but diverging open reading frames (ORFs) of which one, termed entQ, encodes a 34-amino-acid protein whose deduced amino acid sequence was identical to that obtained for EntQ by amino acid sequencing, showing that EntQ, similarly to EntL50A and EntL50B, is synthesized without an N-terminal leader sequence or signal peptide. The second ORF, termed orf2, was located immediately upstream of and in opposite orientation to entQ and encodes a putative immunity protein composed of 221 amino acids. Bacteriocin production by E. faecium L50 showed that EntP and EntQ are produced in the temperature range from 16 to 47°C and maximally detected at 47 and 37 to 47°C, respectively, while EntL50A and EntL50B are maximally synthesized at 16 to 25°C and are not detected at 37°C or above.
Luis M. Cintas - One of the best experts on this subject based on the ideXlab platform.
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identification of bacteriocin genes in enterococci isolated from game animals and saltwater fish
Journal of Food Protection, 2011Co-Authors: Tereza Almeida, Andreia Brandao, Estefania Munozatienza, Luis M. Cintas, Carmen Herranz, Gilberto Igrejas, Alexandre Gonçalves, Carmen Torres, Pablo E. Hernández, Patrícia PoetaAbstract:Bacteriocins produced by enterococci, referred to as Enterocins, possess great interest for their potential use as biopreservatives in food and feed, as well as alternative antimicrobials in humans...
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identification of bacteriocin genes in enterococci isolated from game animals and saltwater fish
Journal of Food Protection, 2011Co-Authors: Tereza Almeida, Andreia Brandao, Estefania Munozatienza, Luis M. Cintas, Carmen Herranz, Gilberto Igrejas, Alexandre Gonçalves, Carmen Torres, Pablo E. Hernández, Patrícia PoetaAbstract:Bacteriocins produced by enterococci, referred to as Enterocins, possess great interest for their potential use as biopreservatives in food and feed, as well as alternative antimicrobials in humans and animals. In this context, the aim of the present study was to determine the antimicrobial activity and the presence of bacteriocin structural genes in fecal enterococcal isolates from animal origins. Evaluation of the direct antimicrobial activity of 253 isolates from wild boars (Sus scrofa, n = 69), mullets (Liza ramada, n = 117), and partridges (Perdix perdix, n = 67) against eight indicator bacterial strains (including Listeria monocytogenes, Pediococcus pentosaceus, and Enterococcus spp.) showed that 177 (70%) exerted antimicrobial activity against at least one indicator microorganism. From these isolates, 123 were further selected on the basis of their inhibition group, and 81 were found to be producers of bacteriocins active against Listeria monocytogenes. Analysis of the presence of enterocin structural genes in a subset of 36 isolates showed that 70% harbored one or more of the evaluated genes, those of enterocin P and hiracin JM79 being the most prevalent. These results show that wild animals constitute an appropriate source for the isolation of bacteriocinogenic enterococci.
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antimicrobial activity of enterococcus faecium l50 a strain producing Enterocins l50 l50a and l50b p and q against beer spoilage lactic acid bacteria in broth wort hopped and unhopped and alcoholic and non alcoholic lager beers
International Journal of Food Microbiology, 2008Co-Authors: Antonio Basanta, Carmen Herranz, Pablo E. Hernández, Jorge Sanchez, Beatriz Gomezsala, Luis M. CintasAbstract:Abstract Enterococcus faecium L50 produces enterocin L50 (L50A and L50B) (EntL50, EntL50A and EntL50B), enterocin P (EntP) and enterocin Q (EntQ) and displays a broad antimicrobial spectrum against the most relevant beer-spoilage lactic acid bacteria (LAB) (i.e., Lactobacillus brevis and Pediococcus damnosus), which is mainly due to the production of EntL50 (EntL50A and EntL50B). Bacteriocin assays using in vitro-synthesized EntL50 (EntL50A and EntL50B) showed that both individual peptides possess antimicrobial activity on their own, EntL50A being the most active, but when the two peptides were combined a synergistic effect was observed. The only virulence genes detected in E. faecium L50 were efaAfm (cell wall adhesin) and ccf (sex pheromone), and this strain was susceptible to most clinically relevant antibiotics. E. faecium L50 survived but did not grow nor showed antimicrobial activity in hopped and unhopped wort, and alcoholic (1 and 5% ethanol, v/v) and non-alcoholic (0% ethanol, v/v) commercial lager beers. However, when unhopped wort was supplemented with 50% (v/v) MRS broth, E. faecium L50 grew and exerted antimicrobial activity similarly as in MRS broth. The Enterocins produced by this strain were bactericidal (5 log decrease) against P. damnosus and Lb. brevis in a dose- and substrate-dependent manner when challenged in MRS broth, wort (hopped and unhopped), and alcoholic (1 and 5% ethanol, v/v) and non-alcoholic (0% ethanol, v/v) lager beers at 32 °C, and no bacterial resistances were detected even after incubation for 6–15 days. The Enterocins in wort and lager beer (5% ethanol, v/v) withstood the heat treatments commonly employed in the brewing industry during mashing, wort boiling, fermentation, and pasteurization, and retained most of their antimicrobial activity in lager beer (5% ethanol, v/v) after long-term storage at 8 and 25 °C.
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biochemical and genetic evidence that enterococcus faecium l50 produces Enterocins l50a and l50b the sec dependent enterocin p and a novel bacteriocin secreted without an n terminal extension termed enterocin q
Journal of Bacteriology, 2000Co-Authors: Luis M. Cintas, Carmen Herranz, P Casaus, Helge Holo, Leiv Sigve Havarstein, Pablo E. HernándezAbstract:Enterococcus faecium L50 grown at 16 to 32°C produces enterocin L50 (EntL50), consisting of EntL50A and EntL50B, two unmodified non-pediocin-like peptides synthesized without an N-terminal leader sequence or signal peptide. However, the bacteriocin activity found in the cell-free culture supernatants following growth at higher temperatures (37 to 47°C) is not due to EntL50. A purification procedure including cation-exchange, hydrophobic interaction, and reverse-phase liquid chromatography has shown that the antimicrobial activity is due to two different bacteriocins. Amino acid sequences obtained by Edman degradation and DNA sequencing analyses revealed that one is identical to the sec-dependent pediocin-like enterocin P produced by E. faecium P13 (L. M. Cintas, P. Casaus, L. S. Havarstein, P. E. Hernandez, and I. F. Nes, Appl. Environ. Microbiol. 63:4321–4330, 1997) and the other is a novel unmodified non-pediocin-like bacteriocin termed enterocin Q (EntQ), with a molecular mass of 3,980. DNA sequencing analysis of a 963-bp region of E. faecium L50 containing the enterocin P structural gene (entP) and the putative immunity protein gene (entiP) reveals a genetic organization identical to that previously found in E. faecium P13. DNA sequencing analysis of a 1,448-bp region identified two consecutive but diverging open reading frames (ORFs) of which one, termed entQ, encodes a 34-amino-acid protein whose deduced amino acid sequence was identical to that obtained for EntQ by amino acid sequencing, showing that EntQ, similarly to EntL50A and EntL50B, is synthesized without an N-terminal leader sequence or signal peptide. The second ORF, termed orf2, was located immediately upstream of and in opposite orientation to entQ and encodes a putative immunity protein composed of 221 amino acids. Bacteriocin production by E. faecium L50 showed that EntP and EntQ are produced in the temperature range from 16 to 47°C and maximally detected at 47 and 37 to 47°C, respectively, while EntL50A and EntL50B are maximally synthesized at 16 to 25°C and are not detected at 37°C or above.
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comparative antimicrobial activity of enterocin l50 pediocin pa 1 nisin a and lactocin s against spoilage and foodborne pathogenic bacteria
Food Microbiology, 1998Co-Authors: Luis M. Cintas, P Casaus, Manuela Fernandez, Pablo E. HernándezAbstract:The present work compares, under the same stated experimental conditions, the antimicrobial activity of crude and purified enterocin L50, pediocin PA-1, nisin A and lactocin S, produced by lactic acid bacteria (LAB) isolated from Spanish dry-fermented sausages. The bacteriocins were purified to homogeneity by ammonium sulphate precipitation, gel filtration (for lactocin S), and cation-exchange, hydrophobic-interaction, and reverse-phase-chromatography; high yields of pure bacteriocins were obtained. Minimal inhibitory concentration (MIC) of pure enterocin L50, pediocin PA-1, nisin A and lactocin S was determined against a broad spectrum of Gram-positive bacteria, including spoilage and foodborne pathogenic bacteria. The purified bacteriocins showed a broad antimicrobial spectrum similar to that exerted by crude bacteriocins. Enterocin L50 and pediocin PA-1 were very active againstListeria monocytogenes, which was quite resistant to nisin A and lactocin S. Enterocin L50 also displayed antimicrobial activity againstStaphylococcus aureus,Clostridium perfringensandClostridium botulinum. However, these pathogens were weakly inhibited, or not at all, by the other pure bacteriocins.
Mercedes Maqueda - One of the best experts on this subject based on the ideXlab platform.
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antimicrobial characterization and safety aspects of the bacteriocinogenic enterococcus hirae f420 isolated from moroccan raw goat milk
Canadian Journal of Microbiology, 2012Co-Authors: F Achemchem, Manuel Martinezbueno, Eva Valdivia, Ruben Cebrian, J Abrini, Mercedes MaquedaAbstract:The F420 strain, isolated from raw goat milk and identified as Enterococcus hirae, was selected because of its strong activity against Gram-positive bacteria, including Listeria monocytogenes. Interestingly, the F420 strain lacks the virulence genes and decarboxylase activity of histidine, lysine, and ornithine, and it is susceptible to 11 of 14 tested antibiotics, including vancomycin. The antimicrobial compounds produced by E. hirae F420 strain showed high resistance to heat treatment and to acidic and basic pHs. The MALDI-TOF mass spectrometry analysis coupled with the sequence of peptide and structural gene analysis of one of the purified Enterocins showed 100% identity with enterocin P (EntP), previously described in E. faecium strains. The structural gene for EntP is located on a plasmid of 65 kb. Other Enterocins with molecular mass higher than 7 kDa were also detected. This is the first report of the production of EntP by E. hirae species naturally occurring in foods. The biotechnological characte...
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Characterization of antimicrobial substances produced by Enterococcus faecalis MRR 10-3, isolated from the uropygial gland of the hoopoe (Upupa epops).
Applied and environmental microbiology, 2006Co-Authors: Antonio M. Martín-platero, Mercedes Maqueda, Eva Valdivia, Magdalena Ruíz-rodríguez, Juan J. Soler, Manuel Martín-vivaldi, Manuel Martínez-buenoAbstract:The uropygial gland (preen gland) is a holocrine secretory gland situated at the base of the tail in birds which produces a hydrophobic fatty secretion. In certain birds, such as the hoopoe, Upupa epops, the composition of this secretion is influenced by both seasonal and sexual factors, becoming darker and more malodorous in females and in their nestlings during the nesting phase. The secretion is spread throughout the plumage when the bird preens itself, leaving its feathers flexible and waterproof. It is also thought to play a role in defending the bird against predators and parasites. We have isolated from the uropygial secretion of a nestling a bacterium that grows in monospecific culture which we have identified unambiguously by phenotypic and genotypic means as Enterococcus faecalis. The strain in question produces antibacterial substances that are active against all gram-positive bacteria assayed and also against some gram-negative strains. Its peptide nature identifies it as a bacteriocin within the group known as Enterocins. Two peptides were purified to homogeneity (MR10A and MR10B), and matrix-assisted laser desorption ionization-time of flight (mass spectrometry) analysis showed masses of 5201.58 and 5207.7 Da, respectively. Amino acid sequencing of both peptides revealed high similarity with enterocin L50A and L50B (L. M. Cintas, P. Casaus, H. Holo, P. E. Hernandez, I. F. Nes, and L. S. Havarstein, J. Bacteriol. 180:1988-1994, 1998). PCR amplification of total DNA from strain MRR10-3 with primers for the L50A/B structural genes and sequencing of the amplified fragment revealed almost identical sequences, except for a single conservative change in residue 38 (Glu→Asp) in MR10A and two changes in residues 9 (Thr→Ala) and 15 (Leu→Phe) in MR10B. This is the first time that the production of bacteriocins by a bacterium isolated from the uropygial gland has been described. The production of these broad-spectrum antibacterial substances by an enterococcal strain living in the uropygial gland may be important to the hygiene of the nest and thus to the health of the eggs and chicks.
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Characterization of antimicrobial substances produced by Enterococcus faecalis MRR 10-3, isolated from the uropygial gland of the hoopoe (Upupa epops
2006Co-Authors: Antonio M. Martín-platero, Mercedes Maqueda, Eva Valdivia, Magdalena Ruíz-rodríguez, Juan J. Soler, Manuel Martín-vivaldi, Manuel Martínez-buenoAbstract:The uropygial gland (preen gland) is a holocrine secretory gland situated at the base of the tail in birds which produces a hydrophobic fatty secretion. In certain birds, such as the hoopoe, Upupa epops, the composition of this secretion is influenced by both seasonal and sexual factors, becoming darker and more malodorous in females and in their nestlings during the nesting phase. The secretion is spread throughout the plumage when the bird preens itself, leaving its feathers flexible and waterproof. It is also thought to play a role in defending the bird against predators and parasites. We have isolated from the uropygial secretion of a nestling a bacterium that grows in monospecific culture which we have identified unambiguously by phenotypic and genotypic means as Enterococcus faecalis. The strain in question produces antibacterial substances that are active against all gram-positive bacteria assayed and also against some gram-negative strains. Its peptide nature identifies it as a bacteriocin within the group known as Enterocins. Two peptides were purified to homogeneity (MR10A and MR10B), and matrix-assisted laser desorption ionization–time of flight (mass spectrometry) analysis showed masses of 5201.58 and 5207.7 Da, respectively. Amino acid sequencing of both peptides revealed high similarity with enterocin L50A and L50B (L. M. Cintas, P. Casaus, H. Holo, P. E
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control of alicyclobacillus acidoterrestris in fruit juices by enterocin as 48
International Journal of Food Microbiology, 2005Co-Authors: Ma Jose Grande, Rosario Lucas, Hikmate Abriouel, Ben N Omar, Mercedes Maqueda, Manuel Martinezbueno, Magdalena Martinezcanamero, Eva Valdivia, Antonio GalvezAbstract:Alicyclobacillus acidoterrestris is a spoilage-causing bacterium in fruit juices. Control of this bacterium by enterocin AS-48 from Enterococcus faecalis A-48-32 is described. Enterocin AS-48 was active against one A. acidocaldarius and three strains of A. acidoterrestris tested. In natural orange and apple juices incubated at 37 °C, vegetative cells of A. acidoterrestris DSMZ 2498 were inactivated by enterocin AS-48 (2.5 μg/ml) and no growth was observed in 14 days. In commercial fruit juices added of AS-48 (2.5 μg/ml) and inoculated with vegetative cells or with endospores of strain DSMZ 2498, no viable cells were detected during 90 days of incubation at temperatures of 37 °C, 15 °C or 4 °C, except for apple, peach and grapefruit juices inoculated with vegetative cells and incubated at 37 °C which were protected efficiently for up to 60 days. Remarkably, in all commercial fruit juices tested, no viable cells were detected as early as 15 min after incubation with the bacteriocin. Endospores incubated for a very short time (1 min) with increasing bacteriocin concentrations were inactivated by 2.5 μg/ml AS-48. Electron microscopy examination of vegetative cells and endospores treated with enterocin AS-48 revealed substantial cell damage and bacterial lysis as well as disorganization of endospore structure.
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enterococcus faecium f58 a bacteriocinogenic strain naturally occurring in jben a soft farmhouse goat s cheese made in morocco
Journal of Applied Microbiology, 2005Co-Authors: F Achemchem, Eva Valdivia, Manuel Martinezbueno, J Abrini, Mercedes MaquedaAbstract:F. ACHEMCHEM, M. MARTINEZ-BUENO, J. ABRINI, E. VALDIVIA AND M. MAQUEDA. 2005. Aims: Characterization of Ent F-58 produced by Enterococcus faecium strain F58 isolated from Jben, a soft, farmhouse goat's cheese manufactured without starter cultures. Methods and Results: E. faecium strain F58 was isolated because of its broad inhibitory spectrum, including activity against food-borne pathogenic and spoilage bacteria. The antimicrobial substance was produced during the growth phase, with maximum production after 16-20 h of incubation at 30� C, and was stable over a wide pH range (4-8) and at high temperatures (5 min at 100� C). The enterocin was purified to homogeneity using cation exchange and hydrophobic interaction on C-18 and reverse-phase high-performance liquid chromatography. The activity was eluted as two individual active fractions (F-58A and F-58B) and matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry analysis showed masses of 5210AE5 and 5234AE3 Da respectively. Both peptides were partially sequenced by Edman degradation, and amino-acid sequencing revealed high similarity with enterocin L50 (I). PCR-amplified fragments containing the structural genes for F-58 A and B were located in a 22-kb plasmid harboured by this strain. We verified that it also holds the structural gene for P-like enterocin. Conclusion: E. faecium strain F58 from Jben cheese, a producer of enterocin L50, exerts an inhibitory effect against strains of genera such as Listeria, Staphylococcus, Clostridium, Brochothrix and Bacillus. Enterocin was characterized according to its functional and biological properties, purification to homogeneity and an analysis of its amino acid and genetic sequences. Significance and Impact of the Study: E. faecium strain F58 is a newly discovered producer of enterocin L50, the biotechnological characteristics of which indicate its potential for application as a protective agent against pathogens and spoilage bacteria in foods.