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1.
Cancer Cell ; 41(8): 1450-1465.e8, 2023 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-37478851

RESUMO

Carnobacterium maltaromaticum was found to be specifically depleted in female patients with colorectal cancer (CRC). Administration of C. maltaromaticum reduces intestinal tumor formation in two murine CRC models in a female-specific manner. Estrogen increases the attachment and colonization of C. maltaromaticum via increasing the colonic expression of SLC3A2 that binds to DD-CPase of this bacterium. Metabolomic and transcriptomic profiling unveils the increased gut abundance of vitamin D-related metabolites and the mucosal activation of vitamin D receptor (VDR) signaling in C. maltaromaticum-gavaged mice in a gut microbiome- and VDR-dependent manner. In vitro fermentation system confirms the metabolic cross-feeding of C. maltaromaticum with Faecalibacterium prausnitzii to convert C. maltaromaticum-produced 7-dehydrocholesterol into vitamin D for activating the host VDR signaling. Overall, C. maltaromaticum colonizes the gut in an estrogen-dependent manner and acts along with other microbes to augment the intestinal vitamin D production to activate the host VDR for suppressing CRC.


Assuntos
Neoplasias Colorretais , Vitamina D , Camundongos , Feminino , Animais , Vitamina D/metabolismo , Carnobacterium/metabolismo , Estrogênios/metabolismo , Receptores de Calcitriol/genética , Receptores de Calcitriol/metabolismo
2.
Int Microbiol ; 26(4): 1033-1040, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37087535

RESUMO

The aim of this study aimed to examine the existence of a bacterial metagenome in the bone marrow of patients with acute myeloid leukemia (AML). We re-examined whole-genome sequencing data from the bone marrow samples of seven patients with AML, four of whom were remitted after treatment, for metagenomic analysis. After the removal of human reads, unmapped reads were used to profile the species-level composition. We used the metagenomic binning approach to confirm whether the identified taxon was a complete genome of known or novel strains. We observed a unique and novel microbial signature in which Carnobacterium maltaromaticum was the most abundant species in five patients with AML or remission. The complete genome of C. maltaromaticum "BMAML_KR01," which was observed in all samples, was 100% complete with 8.5% contamination and closely clustered with C. maltaromaticum strains DSM20730 and SF668 based on single nucleotide polymorphism variations. We identified five unique proteins that could contribute to cancer progression and 104 virulent factor proteins in the BMAML_KR01 genome. To our knowledge, this is the first report of a new strain of C. maltaromaticum in patients with AML. The presence of C. maltaromaticum and its new strain in patients indicates an urgent need to validate the existence of this bacterium and evaluate its pathophysiological role.


Assuntos
Leucemia Mieloide Aguda , Metagenoma , Humanos , Medula Óssea , Carnobacterium/genética , Carnobacterium/metabolismo , Leucemia Mieloide Aguda/genética
3.
Probiotics Antimicrob Proteins ; 12(4): 1562-1570, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32430585

RESUMO

Chitosan films loaded with bacteriocin were examined by FTIR spectroscopy, tested for color, puncture strength, water vapor permeability, and as antimicrobials of Listeria innocua HPB13. Divergicin M35, a bacteriocin produced by Carnobacterium divergens, was incorporated into films made with chitosan of molecular mass 2 kDa, 20 kDa, or 100 kDa and de-acetylated either 87% or 95%. Only 100 kDa chitosan yielded films that could be peeled and handled easily. The higher degree of de-acetylation increased the total color factor (ΔE) of bacteriocin-loaded films, their permeability, and puncture strength. Incorporation of divergicin M35 into the films increased amide I peak intensity but otherwise did not induce significant structural change. The FTIR spectra of divergicin M35 shed from the films did not differ from those of the original free bacteriocin, except in overall peak intensity. The release of active divergicin M35 from the film was faster into the buffer than into tryptic soy broth and peaked at 10-12 h in both cases. Chitosan 95% de-acetylated and loaded with divergicin M35 was the most active, producing a six-log drop in Listeria innocua HPB13 viable count within 24 h. These results suggest that the biocompatible and biodegradable films developed here have the potential for application as antimicrobials of Listeria spp. in foods, especially ready-to-eat, minimally processed products.


Assuntos
Antibacterianos/farmacologia , Bacteriocinas/farmacologia , Carnobacterium/metabolismo , Quitosana/química , Listeria/efeitos dos fármacos , Antibacterianos/química , Antibacterianos/isolamento & purificação , Bacteriocinas/biossíntese , Bacteriocinas/isolamento & purificação , Contagem de Colônia Microbiana , Embalagem de Alimentos/métodos , Humanos , Listeria/crescimento & desenvolvimento , Listeria/patogenicidade , Membranas Artificiais , Peso Molecular , Permeabilidade , Vapor/análise
4.
Microbiologyopen ; 9(1): e00957, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31667956

RESUMO

The two-peptide bacteriocins produced by Gram-positive bacteria require two different peptides, present in equimolar amounts, to elicit optimal antimicrobial activity. Producer organisms are protected from their bacteriocin by a dedicated immunity protein. The immunity proteins for two-peptide bacteriocins contain putative transmembrane domains (TMDs) and might therefore be associated with the membrane. The immunity protein CbnZ for the two-peptide bacteriocin carnobacteriocin XY (CbnXY) was identified by heterologously expressing the cbnZ gene in sensitive host strains. Using protein topology prediction methods and the dual pho-lac reporter system, we mapped out the membrane topology of CbnZ, along with those of the immunity proteins LagC and LciM for the two-peptide bacteriocins lactococcin G and lactococcin MN, respectively. Our results reveal wide structural variety between these immunity proteins that can contain as little as one TMD or as many as four TMDs.


Assuntos
Antibacterianos/metabolismo , Antibiose/genética , Bacteriocinas/genética , Bacteriocinas/metabolismo , Antibiose/fisiologia , Carnobacterium/genética , Carnobacterium/metabolismo , DNA Bacteriano/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Lactococcus lactis/genética , Lactococcus lactis/metabolismo , Conformação Proteica
5.
Appl Environ Microbiol ; 85(20)2019 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-31399404

RESUMO

Carnobacterium maltaromaticum and Carnobacterium divergens are often predominant in the microbiota of vacuum-packaged (VP) meats after prolonged storage at chiller temperatures, and more so in recent studies. We investigated the antibacterial activities of C. maltaromaticum and C. divergens (n = 31) from VP meats by phenotypic characterization and genomic analysis. Five strains showed antibacterial activities against Gram-positive bacteria in a spot-lawn assay, with C. maltaromaticum strains having an intergeneric and C. divergens strains an intrageneric inhibition spectrum. This inhibitory activity is correlated with the production of predicted bacteriocins, including carnobacteriocin B2 and carnolysin for C. maltaromaticum and divergicin A for C. divergens The supernatants of both species cultured in meat juice medium under anaerobic conditions retarded the growth of most Gram-positive and Gram-negative bacteria in broth assay in a strain-dependent manner. C. maltaromaticum and C. divergens produced formate and acetate but not lactate under VP meat-relevant conditions. The relative inhibitory activity by Carnobacterium strains was significantly correlated (P < 0.05) to the production of both acids. Genomic analysis revealed the presence of genes required for respiration in both species. In addition, two clusters of C. divergens have an average nucleotide identity below the cutoff value for species delineation and thus should be considered to be two subspecies. In conclusion, both bacteriocins and organic acids are factors contributing significantly to the antibacterial activity of C. maltaromaticum and C. divergens under VP meat-relevant conditions. A few Carnobacterium strains can be explored as protective cultures to extend the shelf life and improve the safety of VP meats.IMPORTANCE The results of this study demonstrated that both bacteriocins and organic acids are important factors contributing to the antibacterial activities of Carnobacterium from vacuum-packaged (VP) meats. This study demonstrated that formate and acetate are the key organic acids produced by Carnobacterium and demonstrated their association with the inhibitory activity of carnobacteria under VP meat-relevant storage conditions. The role of lactate, on the other hand, may not be as important as previously believed in the antimicrobial activities of Carnobacterium spp. on chilled VP meats. These findings advance our understanding of the physiology of Carnobacterium spp. to better explore their biopreservative properties for chilled VP meats.


Assuntos
Ácidos/farmacologia , Antibacterianos/farmacologia , Bacteriocinas/farmacologia , Carnobacterium/metabolismo , Carne/microbiologia , Acetatos/metabolismo , Antibacterianos/metabolismo , Bacteriocinas/metabolismo , Carnobacterium/classificação , Carnobacterium/genética , Microbiologia de Alimentos , Embalagem de Alimentos , Formiatos/metabolismo , Genoma Bacteriano , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Ácido Láctico/metabolismo , Testes de Sensibilidade Microbiana , Filogenia , Vácuo
6.
J Food Sci ; 84(9): 2592-2602, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31429485

RESUMO

Lactic acid bacteria and Listeria monocytogenes are psychotropic organisms that can grow and compete in food such as lightly preserved fishery products. Predictive microbiology is nowadays one of the leading tools to assess the behavior of bacteria in food and to predict food spoilage. Mathematical models can be used to predict the growth, inactivation or growth probability of bacteria. Currently, the efforts in microbial modeling are oriented towards extrapolation of results beyond experiments in order to predict the growth of interacting microorganisms and develop new food preservation processes. In the present work, a model combining both heterogeneous population and quasi-chemical approaches to describe the different phases of the bacterial growth curve is presented. The model was applied to both monoculture and co-culture cases of lactic acid bacteria, Carnobacterium maltaromaticum H-17, and two Listeria monocytogenes strains in a raw fish extract. It is a highlight that our model includes novel inhibition reactions due to the accumulation of metabolites, and a general equation to take into account the effect of chemical compounds during the lag or physiological adaptation phase of the cells. Our results show that the proposed model can accurately describe the experimental data when the curve shape is a sigmoid, and when it presents a maximum. Besides, the parameters have biological interpretability since the model is mechanistically inspired.


Assuntos
Carnobacterium/metabolismo , Produtos Pesqueiros/microbiologia , Listeria monocytogenes/metabolismo , Modelos Biológicos , Animais , Técnicas de Cocultura , Conservação de Alimentos , Cinética
7.
Food Res Int ; 123: 601-611, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31285009

RESUMO

Cooked pork products, i.e., sliced cooked hams maintained under modified-atmosphere-packaging (MAP), were analysed both microbiologically and with respect to volatile levels during storage. Three storage temperature ranges were compared (4-6 °C, 7-9 °C, and 11-13 °C), representing different refrigeration conditions at household level. The microbial loads were determined by plating samples on six different agar media, followed by (GTG)5-PCR fingerprinting of genomic DNA of selected isolates, and identification of representative isolates by 16S rRNA, pheS, and rpoA gene sequencing. Carnobacterium maltaromaticum, Lactobacillus sakei, and Serratia proteamaculans were the major bacterial species found among the 619 isolates identified. The volatiles produced during storage were followed by selected ion flow tube-mass spectrometry (SIFT-MS) and the identity of the volatiles was confirmed by headspace solid-phase microextraction combined with gas chromatography and time-of-flight mass spectrometry (HS-SPME-GC-TOF-MS). SIFT-MS analysis showed that volatiles, such as 2,3-butanediol, acetoin, and ethanol, may serve as potential markers for spoilage development. Differences in volatile production between samples were likely due to discrepancies in the initial microbial load and the effect of storage conditions. In conclusion, this study combines the use of new mass spectrometric techniques to examine volatile production during spoilage as an additional source of information during microbiological community analysis.


Assuntos
Embalagem de Alimentos , Produtos da Carne/análise , Produtos da Carne/microbiologia , RNA Ribossômico 16S/isolamento & purificação , Compostos Orgânicos Voláteis/análise , Animais , Carga Bacteriana , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Carnobacterium/isolamento & purificação , Carnobacterium/metabolismo , Contagem de Colônia Microbiana , Culinária , Contaminação de Alimentos , Microbiologia de Alimentos , Concentração de Íons de Hidrogênio , Latilactobacillus sakei/isolamento & purificação , Latilactobacillus sakei/metabolismo , Espectrometria de Massas , RNA Ribossômico 16S/metabolismo , Refrigeração , Análise de Sequência de DNA , Serratia/isolamento & purificação , Serratia/metabolismo , Microextração em Fase Sólida , Suínos
8.
Food Res Int ; 122: 517-527, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31229107

RESUMO

Chicken meat is one of the most widely consumed meats worldwide. The microbiota on the whole body of chicken is a potential source of foodborne pathogens that can be transmitted to humans during the preparation of raw meat. However, to date, there have been no studies comparing the microbiota of packaged chicken products and those of raw chicken carcasses from butcher shops, although such information could be useful for identifying sources of contamination in cases of food poisoning. We addressed this in the present study by analyzing the microbiota of 80 chicken meat samples collected from various butcher shops and processing plants in South Korea with the Illumina MiSeq system based on the 16S rRNA gene sequence. The bacterial amounts in chicken samples were estimated by quantitative real-time PCR. Although different microbial members were present in unpackaged meat from butcher shops as compared to those in packaged products from commercial sources, seasonal differences (sample obtained in January vs. July) in microbiota were more significant even in the packaged products from the same company. We also investigated the influence of contaminated foodborne pathogen on the indigenous microbiota (64 chicken samples) by artificially inoculated with Salmonella enterica serotype Virchow on chicken carcasses under various conditions, and carrying out 16S rRNA gene and whole metagenome sequencing. The amount of contaminated Salmonella in chicken meat samples was the highest and lowest in samples stored at 27 °C and 4 °C after washing, respectively. Additionally, the relative abundance of virulence genes was detected lower in samples stored at 4 °C after washing in both butcher shop and commercial samples. These results could be useful for reducing the risk of foodborne illness caused by cross-contamination during the preparation of chicken meat.


Assuntos
Galinhas , Doenças Transmitidas por Alimentos/epidemiologia , Doenças Transmitidas por Alimentos/microbiologia , Aves Domésticas/microbiologia , Animais , Carga Bacteriana , Brochothrix/isolamento & purificação , Brochothrix/metabolismo , Carnobacterium/isolamento & purificação , Carnobacterium/metabolismo , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Embalagem de Alimentos , Sequenciamento de Nucleotídeos em Larga Escala , Metagenômica , Microbiota , Moraxella/isolamento & purificação , Moraxella/metabolismo , Pseudomonas/isolamento & purificação , Pseudomonas/metabolismo , RNA Ribossômico 16S , República da Coreia/epidemiologia , Salmonella enterica/isolamento & purificação , Salmonella enterica/metabolismo , Estações do Ano , Análise de Sequência de DNA , Temperatura
9.
Food Res Int ; 119: 196-206, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30884649

RESUMO

Cooked poultry products are nutritious and economically valuable products that are at risk of bacterial spoilage, which can be postponed by cooling and modified-atmosphere-packaging (MAP). In this study, a cooked chicken product was stored at three different temperature ranges (4-6 °C, 7-9 °C, and 11-13 °C) and volatile production was measured over time using selected ion flow tube-mass spectrometry (SIFT-MS). The identities of the volatiles formed were confirmed by headspace solid-phase microextraction coupled with gas chromatography time-of-flight mass spectrometry (HS-SPME-GC-TOF-MS) analysis. In total, 33 volatiles were proposed using the latter technique and their concentrations were calculated using product ion counts after assignment of these counts to specific volatiles. The results indicated that 1-octen-3-ol, 2,3-butanediol, acetoin, benzaldehyde, ethanol, methylbutanal, and methylbutanol may serve as biomarkers for bacterial growth and/or chemical degradation of cooked poultry products. In parallel, the bacterial loads of the product samples were determined on selective agar media. A total of 495 bacterial isolates was classified and identified by (GTG)5-PCR fingerprinting, followed by gene sequencing of representative cluster isolates. Carnobacterium divergens, Carnobacterium maltaromaticum, Rahnella aquatilis, and Serratia proteamaculans were the most commonly found species, besides minor contributions of Lactobacillus sakei and Hafnia alvei. Differences in volatile profiles could thus be ascribed to variations in bacterial loads and storage temperatures.


Assuntos
Culinária , Cromatografia Gasosa-Espectrometria de Massas , Produtos Avícolas/análise , Compostos Orgânicos Voláteis/análise , Carga Bacteriana , Carnobacterium/isolamento & purificação , Carnobacterium/metabolismo , Contagem de Colônia Microbiana , Enterobacteriaceae/isolamento & purificação , Enterobacteriaceae/metabolismo , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Embalagem de Alimentos , Armazenamento de Alimentos , Concentração de Íons de Hidrogênio , Lactobacillales/isolamento & purificação , Lactobacillales/metabolismo , Microextração em Fase Sólida , Temperatura
10.
J Appl Microbiol ; 126(5): 1468-1479, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30762266

RESUMO

AIM: The aim of this study is to investigate the effect of a broad spectrum of culture conditions on the acidification activity and viability of Carnobacterium maltaromaticum CNCM I-3298, the main technological properties that determine the shelf-life of biological time-temperature integrator (TTI) labels. METHODS AND RESULTS: Cells were cultivated at different temperatures (20-37°C) and pH (6-9·5) according to a modified central composite design and harvested at increasing times up to 10 h of stationary phase. Acidification activity and viability of freeze-thawed concentrates were assessed in medium mimicking the biological label. Acidification activity was influenced by all three culture conditions, but pH and harvest time were the most influential. Viability was not significantly affected by the tested range of culture conditions. CONCLUSIONS: Carnobacterium maltaromaticum CNCM I-3298 must be cultivated at 20°C, pH 6 and harvested at the beginning of stationary phase to exhibit fastest acidification activities. However, if slower acidification activities are pursued, the recommended culture conditions are 30°C, pH 9·5 and a harvest time between 4-6 h of stationary phase. SIGNIFICANCE AND IMPACT OF THE STUDY: Quantifying the impact of fermentation temperature, pH and harvest time has led to a predictive model for the production of biological TTI covering a broad range of shelf-lives.


Assuntos
Carnobacterium , Técnicas de Cultura de Células/métodos , Carnobacterium/metabolismo , Carnobacterium/fisiologia , Meios de Cultura , Fermentação , Viabilidade Microbiana , Temperatura
11.
J Gen Physiol ; 151(4): 505-517, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30696726

RESUMO

Many key cell processes require prior cell uptake of amino acids from the environment, which is facilitated by cell membrane amino acid transporters such as those of the L-type amino acid transporter (LAT) subfamily. Alterations in LAT subfamily amino acid transport are associated with several human diseases, including cancer, aminoacidurias, and neurodegenerative conditions. Therefore, from the perspective of human health, there is considerable interest in obtaining structural information about these transporter proteins. We recently solved the crystal structure of the first LAT transporter, the bacterial alanine-serine-cysteine exchanger of Carnobacterium sp AT7 (BasC). Here, we provide a complete functional characterization of detergent-purified, liposome-reconstituted BasC transporter to allow the extension of the structural insights into mechanistic understanding. BasC is a sodium- and proton-independent small neutral amino acid exchanger whose substrate and inhibitor selectivity are almost identical to those previously described for the human LAT subfamily member Asc-1. Additionally, we show that, like its human counterparts, this transporter has apparent affinity asymmetry for the intra- and extracellular substrate binding sites-a key feature in the physiological role played by these proteins. BasC is an excellent paradigm of human LAT transporters and will contribute to our understanding of the molecular mechanisms underlying substrate recognition and translocation at both sides of the plasma membrane.


Assuntos
Sistema y+ de Transporte de Aminoácidos/química , Sistema y+ de Transporte de Aminoácidos/metabolismo , Proteínas de Bactérias/química , Carnobacterium/metabolismo , Proteínas de Bactérias/metabolismo , Clonagem Molecular , Regulação Bacteriana da Expressão Gênica
12.
Int J Food Microbiol ; 290: 68-75, 2019 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-30300792

RESUMO

The aim of this study was to investigate the synergistic effect of chitosan and bacteriocins against Escherichia coli and Salmonella in media and in lean beef. The inhibitory effects of chitosan and bacteriocins against E. coli AW1.7 and S. enterica Typhimurium in media were determined by a critical dilution assay. The efficacy a bacteriocin-producing strain of Carnobacterium maltaromaticum and high molecular weight chitosan (HMWC) in inactivation of E. coli AW1.7 and S. Typhimurium was evaluated on beef. Current interventions applied in the beef industry, steaming coupled with lactic acid, were used as reference. HMWC demonstrated higher antibacterial activity than water soluble chitosan (WSC) or chitosan oligosaccharides (COS) in media, and the addition of partially purified bacteriocins from C. maltaromaticum UAL307 increased the activity of the chitosan in vitro. The hurdle combinations associated with HMWC inactivated E. coli AW1.7 and S. enterica Typhimurium more effectively on lean beef when compared to steam or steam coupled with lactic acid. When used on beef, addition of bacteriocins and chitosan did not increase the antibacterial efficacy. Cell counts of S. enterica were further reduced during storage in presence of C. maltaromaticum and chitosan; however, this decrease was not dependent on bacteriocin production. In conclusion, addition of chitosan alone or in combination with C. maltaromaticum UAL 307 as protective culture significantly reduces cell counts of E. coli and Salmonella on beef. Results will be useful to improve pathogen intervention treatments in beef processing.


Assuntos
Bacteriocinas/metabolismo , Carnobacterium/metabolismo , Quitosana/metabolismo , Escherichia coli/fisiologia , Viabilidade Microbiana , Carne Vermelha/microbiologia , Salmonella typhimurium/fisiologia , Animais , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Antibiose , Bacteriocinas/farmacologia , Carnobacterium/química , Bovinos , Quitosana/farmacologia , Escherichia coli/efeitos dos fármacos , Microbiologia de Alimentos , Viabilidade Microbiana/efeitos dos fármacos , Salmonella typhimurium/efeitos dos fármacos
13.
FEBS Lett ; 591(10): 1349-1359, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28391617

RESUMO

In this study, we report that CbnX (33 residues) and CbnY (29 residues) comprise a class IIb (two-component) bacteriocin in Carnobacteria. Individually, CbnX and CbnY are inactive, but together act synergistically to exert a narrow spectrum of activity. The structures of CbnX and CbnY in structure-inducing conditions were determined and strongly resemble other class IIb bacteriocins (i.e., LcnG, PlnEF, PlnJK). CbnX has an extended, amphipathic α-helix and a flexible C terminus. CbnY has two α-helices (one hydrophobic, one amphipathic) connected by a short loop and a cationic C terminus. CbnX and CbnY do not appear to interact directly and likely require a membrane-bound receptor to facilitate formation of the bacteriocin complex. This is the first class IIb bacteriocin reported for Carnobacteria.


Assuntos
Bacteriocinas/química , Bacteriocinas/metabolismo , Carnobacterium/metabolismo , Carnobacterium/química , Dicroísmo Circular , Interações Hidrofóbicas e Hidrofílicas , Modelos Moleculares , Multimerização Proteica , Estrutura Secundária de Proteína
14.
Crit Rev Food Sci Nutr ; 57(2): 399-406, 2017 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-25849292

RESUMO

Branched chain aldehyde, 3-methylbutanal is associated as a key flavor compound with many hard and semi-hard cheese varieties. The presence and impact of this flavor compound in bread, meat, and certain beverages has been recently documented, however its presence and consequences regarding cheese flavor were not clearly reported. This paper gives an overview of the role of 3-methylbutanal in cheese, along with the major metabolic pathways and key enzymes leading to its formation. Moreover, different strategies are highlighted for the control of this particular flavor compound in specific cheese types.


Assuntos
Aldeídos/metabolismo , Proteínas de Bactérias/metabolismo , Queijo/análise , Contaminação de Alimentos/prevenção & controle , 3-Metil-2-Oxobutanoato Desidrogenase (Lipoamida)/metabolismo , Aldeídos/análise , Aldeídos/toxicidade , Carboxiliases/metabolismo , Carnobacterium/enzimologia , Carnobacterium/crescimento & desenvolvimento , Carnobacterium/metabolismo , Queijo/microbiologia , Enterococcus/enzimologia , Enterococcus/crescimento & desenvolvimento , Enterococcus/metabolismo , Qualidade dos Alimentos , Glutamato Desidrogenase/metabolismo , Lactobacillus/enzimologia , Lactobacillus/crescimento & desenvolvimento , Lactobacillus/metabolismo , Lactococcus/enzimologia , Lactococcus/crescimento & desenvolvimento , Lactococcus/metabolismo , Controle de Qualidade , Streptococcus/enzimologia , Streptococcus/crescimento & desenvolvimento , Streptococcus/metabolismo , Paladar , Transaminases/metabolismo
15.
J Appl Microbiol ; 121(5): 1268-1274, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27489131

RESUMO

AIMS: The purpose of this study was to isolate, characterize and determine the structure and the antibacterial activities of a bacteriocin produced by Carnobacterium maltaromaticum CPN, a strain isolated from unpasteurized milk Camembert cheese. METHODS AND RESULTS: This bacteriocin, termed maltaricin CPN, was produced at higher amounts in MRS broth at temperatures between 15°C and 25°C. It was purified to homogeneity from culture supernatant by using a simple method consisting of cation-exchange and reversed-phase chromatographies. Mass spectrometry showed that maltaricin was a 4427·29 Da bacteriocin. Its amino acid sequence was determined by Edman degradation which showed that it had close similarity with bacteriocins of the class IIa. Maltaricin CPN consisted in fact of 44 unmodified amino acids including two cysteine residues at positions 9 and 14 linked by a disulphide bond. The antimicrobial activity of maltaricin CPN covered a range of bacteria, with strong activity against many species of Gram-positive bacteria, especially the food-borne pathogen Listeria monocytogenes, but no activity against Gram-negative ones. CONCLUSIONS: In the studied conditions, C. maltaromaticum CPN produced a new class IIa bacteriocin with strong anti-Listeria activity. SIGNIFICANCE AND IMPACT OF THE STUDY: The study covers the purification and the structural characterization of a new bacteriocin produced by strain C. maltaromaticum CPN isolated from Camembert cheese. Its activity against strains of L. monocytogenes and higher production rates at relatively low temperatures show potential technological applications to improve the safety of refrigerated food.


Assuntos
Antibacterianos/química , Bacteriocinas/química , Bacteriocinas/farmacologia , Carnobacterium/metabolismo , Queijo/microbiologia , Sequência de Aminoácidos , Animais , Antibacterianos/biossíntese , Antibacterianos/farmacologia , Bacteriocinas/biossíntese , Bacteriocinas/classificação , Carnobacterium/isolamento & purificação , Bactérias Gram-Positivas/efeitos dos fármacos , Listeria monocytogenes/efeitos dos fármacos
16.
Food Microbiol ; 58: 79-86, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27217362

RESUMO

The dairy population of Carnobacterium maltaromaticum is characterized by a high diversity suggesting a high diversity of the genetic traits linked to the dairy process. As lactose is the main carbon source in milk, the genetics of lactose metabolism was investigated in this LAB. Comparative genomic analysis revealed that the species C. maltaromaticum exhibits genes related to the Leloir and the tagatose-6-phosphate (Tagatose-6P) pathways. More precisely, strains can bear genes related to one or both pathways and several strains apparently do not contain homologs related to these pathways. Analysis at the population scale revealed that the Tagatose-6P and the Leloir encoding genes are disseminated in multiple phylogenetic lineages of C. maltaromaticum: genes of the Tagatose-6P pathway are present in the lineages I, II and III, and genes of the Leloir pathway are present in the lineages I, III and IV. These data suggest that these genes evolved thanks to horizontal transfer, genetic duplication and translocation. We hypothesize that the lac and gal genes evolved in C. maltaromaticum according to a complex scenario that mirrors the high population diversity.


Assuntos
Carnobacterium/genética , Galactose/metabolismo , Variação Genética , Genômica , Lactose/metabolismo , Leite/metabolismo , Animais , Carnobacterium/metabolismo , Hexosefosfatos , Filogenia , Análise de Sequência de DNA , Sintenia
17.
FEMS Microbiol Lett ; 362(10)2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25868912

RESUMO

Carnobacterium jeotgali strain MS3(T) was isolated from traditionally fermented Korean shrimp produced with bay salt. The bacterium belongs to the family Carnobacteriaceae, produces lactic acid and contains gene clusters involved in the production of lactate, butyrate, aromatic compounds and exopolysaccharides. Carnobacterium jeotgali strain MS3(T) was characterized through extensive comparison of the virulence potential, genomic relatedness and sequence similarities of its genome with the genomes of other Carnobacteria and lactic acid bacteria. In addition, links between predicted functions of genes and phenotypic characteristics, such as antibiotic resistance and lactate and butyrate production, were extensively evaluated. Genomic and phenotypic analyses of strain MS3(T) revealed promising features, including minimal virulence genes and lactate production, which make this bacterium a desirable candidate for exploitation by the fermented food industry.


Assuntos
Carnobacterium/genética , Carnobacterium/isolamento & purificação , Conservação de Alimentos/métodos , Penaeidae/microbiologia , Alimentos Marinhos/microbiologia , Animais , Butiratos/metabolismo , Carnobacterium/metabolismo , Carnobacterium/patogenicidade , Fermentação , Genoma Bacteriano , Ácido Láctico/metabolismo , Lactobacillaceae/genética , Dados de Sequência Molecular , Família Multigênica , Fenótipo , Alinhamento de Sequência , Análise de Sequência de DNA , Virulência/genética
18.
Microbiology (Reading) ; 160(Pt 8): 1670-1678, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24858287

RESUMO

Piscicolin 126 is a class 2a bacteriocin produced by Carnobacterium maltaromaticum strains UAL26 and JG126. Whilst strain UAL26 shows temperature-dependent piscicolin 126 production, strain JG126 produces bacteriocin at any growth temperature. Several clones containing combinations of the ATP-binding cassette transporter (pisT) and transporter accessory (pisE) genes from JG126 and UAL26 were created and tested for bacteriocin production. Bacteriocin production at 25 °C was observed only for a clone containing both pisT and pisE from JG126 (U-T(J)E(J)) and a clone containing pisT from UAL26 and pisE from JG126 (U-BamT(U)E(J)). Therefore, the deletion of a single CG base pair located on pisE of UAL26 that results in a frameshift and truncation of PisE causes the temperature-dependent piscicolin 126 production. Bacteriocin production of UAL26 was induced at 25 °C by the addition of supernatant containing the autoinducer peptide (AIP); however, the antimicrobial activity was lost after two subsequent overnight cultivations due to the presumed lack of the AIP. Changes in membrane fluidity due to changes in temperature or the presence of 2-phenylethanol (PHE) affected bacteriocin production of UAL26, but not of clones U-T(J)E(J) or U-BamT(U)E(J). Similarly, increased membrane fluidity due to PHE addition reduced production of sakacin A in Lactobacillus sakei Lb706 and Lactobacillus curvatus LTH 1174. The mechanism involved in the temperature-dependent piscicolin 126 production was described. Due to the conformational change in PisE at 25 °C, the transport machinery was not able to translocate AIP. To the best of our knowledge, this is the first report that links membrane fluidity with the regulation of bacteriocin production.


Assuntos
Antibacterianos/biossíntese , Bacteriocinas/biossíntese , Carnobacterium/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Carnobacterium/genética , Regulação Bacteriana da Expressão Gênica , Lactobacillus/genética , Lactobacillus/metabolismo , Temperatura
19.
Water Sci Technol ; 69(1): 9-14, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24434962

RESUMO

In order to study the performance and bacterial communities of an anaerobic fluidized bed microbial fuel cell (AFB-MFC) system, the 16S rDNA gene sequencing was applied, and high-strength synthetic wastewater was treated by the AFB-MFC system. The high-strength synthetic wastewater, in which the concentrations of chemical oxygen demand (COD), nitrite nitrogen, and nitrate nitrogen were above 19,000, 2,516-3,871 and 927-1,427 mg/L, was treated by the AFB-MFC system. The removal efficiency of COD, nitrite nitrogen, and nitrate nitrogen reached 70-89, 98 and 98%, while the maximum voltage was 394 mV. The bacteria analysis revealed the presence of Alistipes putredinis, Carnobacterium sp., Victivallis vadensis, Klebsiella pneumoniae, Thauera sp., Parabacteroides merdae, Parvimonas micra, Parabacteroides sp., and Desulfomicrobium baculatum in the anode chamber. In addition, the Klebsiella pneumoniae was observed to have the capability of organic degradation and electricity generation, while the Thauera sp. has the capability of denitrification.


Assuntos
Fontes de Energia Bioelétrica , Águas Residuárias/química , Águas Residuárias/microbiologia , Bactérias/metabolismo , Análise da Demanda Biológica de Oxigênio , Carnobacterium/metabolismo , Nitratos/metabolismo , Nitrogênio/metabolismo
20.
World J Microbiol Biotechnol ; 30(2): 399-406, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23933805

RESUMO

Wilt disease of soybean caused by a very common soil-borne fungus, Fusarium oxysporum is one of the most destructive diseases of the crop. The aim of the present study was to characterize plant growth-promotion activities and induced resistance of a rhizobacterial strain for the soybean plant against F. oxysporum. Rhizobacterium strain SJ-5 exhibited plant growth-promotion characteristics and antagonistic activity against the test pathogen on dual plate assay. It was identified as a Carnobacterium sp. A 950 bp PCR product was amplified from Carnobacterium sp. strain SJ-5, using zwittermicin A self-resistance gene-specific primers (zmaR). The strain produced indole 3-acetic acid (19 µg/ml) in the presence of salt stress and exhibited growth in Dworkin and Foster salt medium amended with 1-aminocyclopropane-1-carboxylate (ACC) through ACC deaminase activity (277 nmol/mg/h) as compared to the control. Strain seeds treated with the strain significantly enhanced the quorum of healthy plants after challenge inoculation at 14 days after seeding. An increase in the activity of stress enzymes after challenge inoculation with the test pathogen is reported. Treatment with the bacterium resulted in an increase in the chlorophyll content in the leaves in comparison with challenge-inoculated plants.


Assuntos
Carnobacterium/fisiologia , Fusarium/crescimento & desenvolvimento , Glycine max/crescimento & desenvolvimento , Glycine max/microbiologia , Doenças das Plantas/prevenção & controle , Carnobacterium/genética , Carnobacterium/metabolismo , Clorofila/análise , Proteínas de Choque Térmico/biossíntese , Ácidos Indolacéticos/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Folhas de Planta/química , Glycine max/enzimologia
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