RESUMEN
A novel, Gram-positive, facultatively anaerobic, and non-motile bacterial strain, designated B2T-5T, was isolated from jeotgal, a traditional Korean fermented seafood. Colonies grown on gifu anaerobic medium agar plates were cream-coloured, irregular, and umbonate with curled margins. Optimal growth of strain B2T-5T occurred at 20 °C, pH 8.0, and in the presence of 1% (w/v) NaCl. Strain B2T-5T was negative for oxidase and catalase activity. Hippurate was not hydrolysed and acetoin was not produced. The major cellular fatty acids were C18â:â1 ω9c and C16â:â0. The cell-wall peptidoglycan was of the A4α type containing l-Lys-d-Asp. The predominant respiratory quinone was menaquinone 7. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylcholine. According to the phylogenetic analysis based on 16S rRNA gene sequences, strain B2T-5T was most closely related to Vagococcus teuberi DSM 21459T, showing 98.2% sequence similarity. Genome sequencing of strain B2T-5T revealed a genome size of 2.0 Mbp and a G+C content of 33.8 mol%. The average nucleotide identities of strain B2T-5T with Vagococcus teuberi DSM 21459T, Vagococcus bubulae SS1994T, and Vagococcus martis D7T301T were 75.0, 74.7, and 75.1%, respectively. Based on the phenotypic, chemotaxonomic, and genotypic data, strain B2T-5T represents a novel species of the genus Vagococcus, for which the name Vagococcus jeotgali sp. nov. is proposed. The type strain is B2T-5T (=KCTC 21223T=JCM 35937T).
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Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano , Ácidos Grasos , Alimentos Fermentados , Peptidoglicano , Filogenia , ARN Ribosómico 16S , Alimentos Marinos , Análisis de Secuencia de ADN , Vitamina K 2 , ARN Ribosómico 16S/genética , Ácidos Grasos/análisis , Alimentos Marinos/microbiología , ADN Bacteriano/genética , República de Corea , Vitamina K 2/análogos & derivados , Vitamina K 2/análisis , Animales , Alimentos Fermentados/microbiología , Secuenciación Completa del Genoma , Enterococcaceae/aislamiento & purificación , Enterococcaceae/genética , Enterococcaceae/clasificación , Genoma Bacteriano , Fermentación , Microbiología de AlimentosRESUMEN
This study explored the dynamics of anchovy sauce fermentation and investigated how the raw material form and the use of starter cultures affect bacterial and metabolite profiles. Using a comprehensive approach, we examined the fermentation process using anchovies in two forms (whole and ground) and three different starter cultures. The use of ground anchovies resulted in an accelerated fermentation process for anchovy sauce; however, the increased diversity of bacterial phylotypes and altered accumulation of biogenic amines were observed. Inoculation of starter cultures resulted in a shift from spontaneous to controlled fermentation, highlighting their ability to regulate bacterial communities. Despite a slightly reduced fermentation rate, inoculation with Tetragenococcus halophilus was shown to be a potent method for reducing biogenic amines and affecting metabolite profiles. As the industry strives to balance fermentation speed and quality, our research could provide insights for improving the efficiency, safety, and quality of anchovy sauce production.
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Fermentación , Alimentos Fermentados , Productos Pesqueros , Microbiología de Alimentos , Alimentos Fermentados/microbiología , Productos Pesqueros/microbiología , Animales , Aminas Biogénicas/metabolismo , Peces/microbiología , Enterococcaceae/metabolismo , Bacterias/metabolismo , Bacterias/clasificación , Microbiota/fisiologíaRESUMEN
Disease outbreaks negatively affect fish production. Antimicrobial agents used in the treatment of diseases become ineffective over time because of antibiotic resistance developed by bacteria distributed in the aquaculture environment. This study was conducted for 4 months (cold period) in a fish farm to detect the fish disease, cold water streptococcosis. In the study, four brood stock showing disease signs were detected. Bacteria isolates were obtained and identified as Vagococcus salmoninarum. Antimicrobial susceptibility of V. salmoninarum was tested and antibiotic resistance gene profiles of V. salmoninarum isolates were screened. The phylogenetic relation of the isolates with the previously reported strains was evaluated. Antibiotic resistance developed by pathogenic bacteria is distributed in the aquaculture environment. The transfer of resistance genes from one bacterium to another is very common. This situation causes the antimicrobial agents used in the treatment of diseases to become ineffective over time. The disc diffusion test showed that all four isolates developed resistance to 13 (FFC30, AX25, C30, E15, CF30, L2, OX1, S10, T30, CRO30, CC2, PT15 and TY15) of the evaluated antibiotics and were about to develop resistance to six others (AM 10, FM 300, CFP75, SXT25, APR15 and TE30). Furthermore, antibiotic resistance genes tetA, sul1, sul2, sul3, dhfr1, ereB and floR were detected in the isolated strain. Moreover, the phylogenetic analysis showed that isolated V. salmoninarum strain (ESN1) was closely related to the bacterial strains isolated from USA and Jura.
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Antiinfecciosos , Cocos Grampositivos , Oncorhynchus mykiss , Animales , Oncorhynchus mykiss/microbiología , Filogenia , Enterococcaceae/genética , Antibacterianos/farmacologíaRESUMEN
Honey bees can be affected by a variety of pathogens, which impacts their vital role as pollinators in agriculture. A cross-sectional study was conducted in southwestern Quebec to: i) estimate the prevalence of 11 bee pathogens; ii) assess the agreement between beekeeper suspicion of a disease and laboratory detection of the causative pathogen; and iii) explore the association between observed clinical signs and pathogen detection in a colony. A total of 242 colonies in 31 apiaries owned by 15 beekeepers was sampled in August 2017. The prevalence of Varroa destructor detection was estimated as 48% for colonies and 93% for apiaries. The apparent prevalence of colonies infected by Nosema spp. and Melissococcus plutonius was estimated as 40% and 21%, respectively. At least 180 colonies were tested by polymerase chain reaction (PCR) for deformed wing virus (DWV), acute-Kashmir-Israeli complex (AKI complex), and black queen cell virus (BQCV), which were detected in 33%, 9%, and 95% of colonies, respectively. Acarapis woodi, Paenibacillus larvae, and Aethina tumida were not detected. Varroasis was suspected by beekeepers in 14 of the 15 beekeeping operations in which the mite was detected. However, no correlation was found between suspected European foulbrood and detection of M. plutonius or between suspected nosemosis and detection of Nosema spp. Colony weakness was associated with Nosema spore counts of at least 0.5 × 106 per bee. Melissococcus plutonius was more frequently detected in colonies showing scattered brood.
Les abeilles mellifères peuvent être affectées par plusieurs agents pathogènes, impactant leur rôle vital de pollinisateur en agriculture. Une étude transversale a été réalisée dans le sud-ouest du Québec afin 1) d'estimer la prévalence de onze agents pathogènes de l'abeille, 2) d'évaluer l'accord entre la suspicion d'une maladie par l'apiculteur et la détection de l'agent causal, 3) d'explorer les associations entre les signes cliniques et la détection d'un agent pathogène dans une colonie. Au total, 242 colonies de 31 ruchers appartenant à 15 apiculteurs ont été échantillonnées en août 2017. La prévalence de Varroa destructor a été estimée à 48 % pour les colonies et à 93 % pour les ruchers. La prévalence apparente de colonies infectées par Nosema spp. ou Melissococcus plutonius a été estimée à respectivement 40 % et 21 %. Le virus des ailes déformées, le complexe viral AKI et le virus de la reine noire ont été détectés dans respectivement 33 %, 9 % et 95 % dans des 180 colonies testées par PCR. Acarapis woodi, Paenibacillus larvae et Aethina tumida n'ont pas été détectés. La varroase était suspectée par les apiculteurs de 14 des 15 entreprises où la mite a été détectée. Aucune corrélation n'a été trouvée entre la suspicion de loque européenne et la détection de M. plutonius ou entre la suspicion de nosémose et la détection de Nosema spp. La faiblesse des colonies a été associée à des comptes de Nosema d'au moins 0,5 × 106 spores par abeille. Melissococcus plutonius était plus fréquemment détecté parmi les colonies présentant du couvain en mosaïque.(Traduit pas les auteurs).
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Estudios Transversales , Enterococcaceae , Virus ARN , Abejas , Animales , Quebec/epidemiología , PrevalenciaRESUMEN
Aggregating strains of Tetragenococcus halophilus tend to be trapped during soy sauce mash-pressing process and are, therefore, critical for clear soy sauce production. However, the precise molecular mechanism involved in T. halophilus aggregation remains elusive. In previous studies, we isolated a number of aggregating strains, including T. halophilus AB4 and AL1, and showed that a cell surface proteinaceous aggregation factor is responsible for their aggregation phenotype. In the present study, we explored the role of polysaccharide intercellular adhesin (PIA) in aggregate formation in T. halophilus SL10, isolated from soy sauce. SL10 exhibited similar aggregation to AB4 and AL1 but formed a non-uniform precipitate with distinctive wrinkles at the bottom of the test tube, unlike AB4 and AL1. Insertion sequence mutations in each gene of the ica operon diminished aggregation and PIA production, highlighting the critical role of IcaADBC-mediated PIA production in T. halophilus aggregation. Furthermore, two non-aggregating cardiolipin synthase (cls) gene mutants with intact ica operon did not produce detectable PIA. Phospholipid composition analysis in cls mutants revealed a decrease in cardiolipin and an increase in phosphatidylglycerol levels, highlighting the association between phospholipid composition and PIA production. These findings provide evidence for the pivotal role of cls in PIA-mediated aggregation and lay the foundation for future studies to understand the intricate networks of the multiple aggregation factors governing microbial aggregation.IMPORTANCEAggregation, commonly observed in various microbes, triggers biofilm formation in pathogenic variants and plays a beneficial role in efficient food production in those used for food production. Here, we showed that Tetragenococcus halophilus, a microorganism used in soy sauce fermentation, forms aggregates in a polysaccharide intercellular adhesin (PIA)-mediated manner. Additionally, we unveiled the relationship between phospholipid composition and PIA production. This study provides evidence for the presence of aggregation factors in T. halophilus other than the proteinaceous aggregation factor and suggests that further understanding of the coordinated action of these factors may improve clarified soy sauce production.
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Fosfolípidos , Fosfolípidos/metabolismo , Enterococcaceae/metabolismo , Enterococcaceae/genética , Polisacáridos Bacterianos/metabolismo , Adhesión Bacteriana , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genéticaRESUMEN
Cantonese soy sauce (CSS) is an important Chinese condiment due to its distinctive flavor. Microorganisms play a significant role in the flavor formation of CSS during fermentation. However, the correlation between microbes and flavor compounds as well as the potential fermentation mechanism remained poorly uncovered. Here we revealed the dynamic changes of microbial structure and characteristics metabolites as well as their correlation of CSS during the fermentation process. Metagenomics sequencing analysis showed that Tetragenococcus halophilus, Weissella confusa, Weissella paramesenteroides, Aspergillus oryzae, Lactiplantibacillus plantarum, Weissella cibaria were top six dominant species from day 0 to day 120. Sixty compounds were either positively or tentatively identified through untargeted metabolomics profile and they were 27 peptides, amino acids and derivatives, 8 carbohydrates and conjugates, 14 organic acids and derivatives, 5 amide compounds, 3 flavonoids and 3 nucleosides. Spearman correlation coefficient indicated that Tetragenococcus halophilus, Zygosaccharomyces rouxii, Pediococcus pentosaceus and Aspergillus oryzae were significantly related with the formation of taste amino acids and derivatives, peptides and functional substances. Additionally, the metabolisms of flavor amino acids including 13 main free amino acids were also profiled. These results provided valuable information for the production practice in the soy sauce industry.
Asunto(s)
Aspergillus oryzae , Enterococcaceae , Alimentos de Soja , Fermentación , Aminoácidos , Aspergillus oryzae/genética , PéptidosRESUMEN
BACKGROUND: Vagococcal infections are extremely rare in humans. There are limited studies on the optimal methods for identification, antimicrobial susceptibility testing, and clinical manifestations of vagococcal infections. Herein, we report a patient with a urinary tract infection who had Vagococcus fluvialis in the urine. CASE PRESENTATION: An 84-year-old man presented to our urology department with a fever that had persisted for several days. He previously worked as a zoo clerk. The patient underwent a left nephroureterectomy for ureteral cancer 5 years ago, and total cystectomy and right cutaneous ureterostomy for muscle-invasive bladder cancer 1 year prior. He was empirically treated with 500 mg of levofloxacin intravenously every 24 h for the urinary tract infection. V. fluvialis was detected in his urine samples and Pseudomonas aeruginosa was detected in his urine and blood samples. Two bacterial species were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. He was administered intravenous levofloxacin for approximately 1 week, followed by oral levofloxacin for another week, after which the infections were eradicated. CONCLUSIONS: To the best of our knowledge, this is the first report of V. fluvialis detected in human urine in Japan. Vagococcus spp. is commonly isolated from fish or animals, and based on the patient's work history, it is possible that the patient was a carrier because of transmission from animals.
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Cocos Grampositivos , Infecciones Urinarias , Anciano de 80 o más Años , Humanos , Masculino , Enterococcaceae , Japón , Levofloxacino , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Infecciones Urinarias/microbiologíaRESUMEN
Tyramine, a trace monoamine produced from tyrosine by decarboxylation and found naturally in foods, plants, and animals, is a suspected virulence factor of Melissococcus plutonius that causes European foulbrood in honey bee brood. In the present study, we developed a method for quantitative analysis of tyramine in culture medium and honey bee larvae with a limit of quantitation of 3 ng/mL and a recovery rate of >97% using Liquid Chromatography-Mass Spectrometry/Mass Spectrometry and deuterium-labeled tyramine, demonstrating for the first time that a highly virulent M. plutonius strain actually produces tyramine in infected larvae. This method will be an indispensable tool to elucidate the role of tyramine in European foulbrood pathogenesis in combination with exposure bioassays using artificially reared bee larvae.
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Enterococcaceae , Larva , Tiramina , Animales , Larva/microbiología , Abejas/microbiología , Tiramina/análisis , Enterococcaceae/aislamiento & purificación , Cromatografía Liquida/veterinaria , Espectrometría de Masas en Tándem/veterinariaRESUMEN
Vagococcus fluvialis infection is rare in humans, and there is limited research on the clinical manifestations and antimicrobial susceptibility testing of Vagococcus fluvialis infection. Here, We isolated Vagococcus fluvialis from the urine samples of bladder cancer patients at Hunan Provincial People's Hospital, and it is the first reported case of Vagococcus fluvialis isolated from the urine. The fully automated microbial identification system and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) identified the bacterium as Vagococcus fluvialis with a confidence level of 99.9%. The VITEK-2Compact fully automated microbial susceptibility analysis system indicated that it was most sensitive to tigecycline, vancomycin, quinupristin/dalfopristin, linezolid, and showed moderate sensitivity to erythromycin, levofloxacin, ciprofloxacin, ampicillin/sulbactam, and tetracycline. Additionally, it exhibited synergy when combined with high-level gentamicin and vancomycin, showing sensitivity. However, it displayed poor activity against penicillin and furanth. According to our knowledge, this is the first study to isolate and identify Vagococcus fluvialis from the urine of bladder cancer patients and the systematically reviewed other reported Vagococcus infections on human, which provide an experimental basis for guiding the rational use of drugs in the clinical treatment and diagnose of Vagococcus fluvialis infection and related pathogenic mechanism research. Meanwhile, we have systematically reviewed other reported.
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Cocos Grampositivos , Neoplasias de la Vejiga Urinaria , Humanos , Vancomicina , Pruebas de Sensibilidad Microbiana , Enterococcaceae , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodosRESUMEN
Tetragenococcus halophilus is a halophilic bacterium that existed in the fermentation of soy sauce and miso for flavor production and probiotic benefits. However, it is composed of two subgroups, histamine-producing and non-histamine-producing, with the former causing histamine accumulation and offering risks to food safety. Exploring the evolutionary mechanisms and physiological function of histamine-biosynthesis is of significance for understanding the formative mechanism of T. halophilus's strain-specificity and is helpful for microbial control. Using systematic genomic analysis, we found that plasmid acquisition and loss is the evolutionary form resulting in the two subgroups of T. halophilus. Two plasmids, plasmid α with 30 kb and plasmid ß with 4 kb existed in histamine-producing T. halophilus. We investigated the whole genetic information and proposed their genetic function in both two plasmids. The acquisition of histamine-producing plasmid enhanced the acid tolerance of histamine-producing T. halophilus but did not affect salt tolerance. More interestingly, we found that the existence of plasmid will promote the co-culture growth of T. halophilus. This study deepens our understanding of the formative mechanism of microbial species diversity, and provides our knowledge of the physiological function of histamine-producing plasmids.
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Enterococcaceae , Histamina , Plásmidos/genética , Enterococcaceae/genética , Evolución BiológicaRESUMEN
Paenibacillus larvae and Melissococcus plutonius represent the most threatening bacterial diseases of honeybee (Apis mellifera)-American and European foulbrood, respectively. For efficient control of those diseases, rapid and accurate detection of the pathogens is crucial. Therefore, we developed a novel multiplex PCR method simultaneously detecting both pathogens. To design and optimize multiplex PCR reaction, four strains of P. larvae representing four ERIC genotypes I-IV (strain DSM 7030-ERIC I, DSM 25430-ERIC II, LMG 16252-ERIC III, DSM 3615-ERIC IV) were selected. Those strains were fully sequenced using long-read sequencing (Sequel I, Pacific Biosciences). For P. larvae, the multicopy insertion sequence IS256 identified in all genotypes of P. larvae was selected to provide high sensitivity. M. plutonius was detected by plasmid pMP1 sequence and the virulence verified by following detection of ETX/MTX2 toxin responsible for pore formation in the cell membrane. As an internal control, a gene encoding for major royal jelly protein 1 specific for honeybees was selected. The method was validated on 36 clinical specimens collected from the colonies suffering from American and European foulbrood in the Czech Republic. Based on the results, sensitivity of PCR was calculated to 93.75% and specificity to 100% for P. larvae diagnosed from hive debris and 100% sensitivity and specificity for honeybee workers and larval scales as well as for diseased brood infected by M. plutonius.
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Enterococcaceae , Paenibacillus larvae , Paenibacillus , Abejas/genética , Animales , Paenibacillus larvae/genética , Elementos Transponibles de ADN , Larva/microbiología , Plásmidos/genética , Reacción en Cadena de la Polimerasa Multiplex/métodos , Paenibacillus/genéticaRESUMEN
RESEARCH HIGHLIGHTS: Large number of bacteria isolated from femoral heads of clinically healthy broilers.The prevailing taxa in femoral heads were Escherichia/Shigella and Enterococcus spp.Continuous presence of bacteria in blood and liver of clinically healthy broilers.Enterobacteriaceae, Enterococcaceae, and Staphylococcaceae prevail in blood and liver.
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Cabeza Femoral , Enfermedades de las Aves de Corral , Humanos , Animales , Enterobacteriaceae , Pollos , Enterococcaceae , Bacterias , Enfermedades de las Aves de Corral/microbiologíaRESUMEN
BACKGROUND: Tetragenococcus halophilus is a halophilic lactic acid bacterium (LAB) isolated from soya sauce moromi. During the production of these fermented foods, acid stress is an inevitable environmental stress. In our previous study, T. halophilus could form biofilms and the cells in the biofilms exhibited higher cell viability under multiple environmental stresses, including acid stress. RESULTS: In this study, the effect of preformed T. halophilus biofilms on cell survival, cellular structure, intracellular environment, and the expression of genes and proteins under acid stress was investigated. The result showed that acid stress with pH 4.30 for 1.5 h reduced the live T. halophilus cell count and caused cellular structure damage. However, T. halophilus biofilm cells exhibited greater cell survival under acid stress than the planktonic cells, and biofilm formation reduced the damage of acid stress to the cell membrane and cell wall. The biofilm cells maintained a higher level of H+ -ATPase activity and intracellular ammonia concentration after acid stress. The RNA-Seq and iTRAQ technologies revealed that the genes and proteins associated with ATP production, the uptake of trehalose and N-acetylmuramic acid, the assembly of H+ -ATPase, amino acid biosynthesis and metabolism, ammonia production, fatty acid biosynthesis, CoA biosynthesis, thiamine production, and acetoin biosynthesis might be responsible for the stronger acid tolerance of T. halophilus biofilm cells together. CONCLUSION: These findings further explained the mechanisms that allowed LAB biofilm cells to resist environmental stress. © 2023 Society of Chemical Industry.
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Amoníaco , Enterococcaceae , Lactobacillales , RNA-Seq , Estructuras Celulares , Adenosina TrifosfatasasRESUMEN
Aspartate/alanine exchange transporter (AspT) is a secondary transporter isolated from the lactic acid bacterium Tetragenococcus halophilus D10 strain. This transporter cooperates with aspartate decarboxylase to produce proton-motive force through decarboxylative phosphorylation. A method that successfully analyzes the AspT mechanism could serve as a prototype for elucidating the substrate transport mechanism of other exchange transporters; therefore, the purpose of this study was to search for conditions that improve the thermal stability of AspT for 3D structure analysis. We used the fluorescence size-exclusion chromatography-based thermostability assay to evaluate conditions that contribute to AspT stability. We found that the AspT thermostability was enhanced at pH 5.0 to 6.0 and in the presence of Na+ and Li+. Pyridoxal phosphate, a coenzyme of aspartate decarboxylase, also had a thermostabilizing effect on AspT. Under the conditions obtained from these results, it was possible to increase the temperature at which 50% of dimer AspT remained by 14°C. We expect these conditions to provide useful information for future structural analysis of AspT.
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Alanina , Ácido Aspártico , Alanina/química , Proteínas de Transporte de Membrana , EnterococcaceaeRESUMEN
IMPORTANCE: Tetragenococcus halophilus is a halophilic lactic acid bacterium generally used as a starter culture in fermenting soy and fish sauces. Aggregating strains can be useful in fermenting and obtaining clear soy sauce because cell clumps are trapped by the filter cake when the soy sauce mash is pressed. However, the genetic mechanisms of aggregation in T. halophilus are unknown. In this study, we identified genes encoding aggregation factor and its regulator. These findings may provide a foundation for developing improved T. halophilus starter cultures for soy sauce fermentation, leading to more efficient and consistent clear soy sauce production.
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Enterococcaceae , Lactobacillales , Animales , Enterococcaceae/genética , Lactobacillales/genética , Operón , FermentaciónRESUMEN
This study aimed to enhance exopolysaccharide production by Tetragenococcus halophilus, and results showed that low temperature (20 °C) significantly improved exopolysaccharide production. Based on the analysis of batch fermentation kinetic parameters, a temperature-shift strategy was proposed, and the exopolysaccharide yield was increased by 28 %. Analysis of the structure of exopolysaccharide suggested that low temperature changed the molecular weight and monosaccharide composition. Transcriptomic analysis was performed to reveal mechanisms of low temperature improving exopolysaccharide production. Results suggested that T. halophilus regulated utilization of carbon sources through phosphotransferase system and increased the expression of key genes in exopolysaccharide biosynthesis to improve exopolysaccharide production. Meanwhile, metabolic pathways involved in glycolysis, amino acids synthesis, two-component system and ATP-binding cassette transporters were affected at low temperature. Results presented in this paper provided a theoretical basis for biosynthetic pathway of exopolysaccharide in T. halophilus and aided to strengthen its production and application in many areas.
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Perfilación de la Expresión Génica , Transcriptoma , Transcriptoma/genética , Temperatura , Enterococcaceae/genética , Enterococcaceae/metabolismoRESUMEN
Fermented fish and fermented fish-based products are part of the diet of many countries all over the world. Their popularity is not only due to the unique flavor, the distinct texture, and the good nutritional quality, but also to the easiness of the production process, that is commonly based on empirical traditional methods. Fish fermentation techniques ususally rely on the combination of some key steps, including salting, addition of spices or additives, and maintenance of anaerobic conditions, thus selecting for the multiplication of some pro-technological microorganisms. The objective of the present review was to provide an overview of the current knowledge of the microbial communities occurring in fermented fish and fish-based products. Specific information was collected from scientific publications published from 2000 to 2022 with the aim of generating a comprehensive database. The production of fermented fish and fish-based foods was mostly localized in West African countries, Northern European countries, and Southeast Asian countries. Based on the available literature, the microbial composition of fermented fish and fish-based products was delineated by using viable counting combined with identification of isolates, and culture-independent techniques. The data obtained from viable counting highlighted the occurrence of microbial groups usually associated with food fermentation, namely lactic acid bacteria, staphylococci, Bacillus spp., and yeasts. The identification of isolates combined with culture-independent methods showed that the fermentative process of fish-based products was generally guided by lactobacilli (Lactiplantibacillus plantarum, Latilactobacillus sakei, and Latilactobacillus curvatus) or Tetragenococcus spp. depending on the salt concentration. Among lactic acid bacteria populations, Lactococcus spp., Pediococcus spp., Leuconostoc spp., Weissella spp., Enterococcus spp., Streptococcus spp., and Vagococcus spp. were frequently identified. Staphylococcus spp. and Bacillus spp. confirmed a great adaptation to fermented fish-based products. Other noteworthy bacterial taxa included Micrococcus spp., Pseudomonas spp., Psychrobacter spp., Halanaerobium spp., and Halomonas spp. Among human pathogenic bacteria, the occurrence of Clostridium spp. and Vibrio spp. was documented. As for yeast populations, the predominance of Candida spp., Debaryomyces spp., and Saccharomyces spp. was evidenced. The present literature review could serve as comprehensive database for the scientific community, and as a reference for the food industry in order to formulate tailored starter or adjunctive cultures for product improvement.
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Aclimatación , Bacillus , Animales , Humanos , África Occidental , Candida , Bases de Datos Factuales , Enterococcaceae , PecesRESUMEN
During our studies on spoilage microbiomes of modified atmosphere packaged broiler meat, we isolated three strains (PNs007T, STAA11T and STAA25) of unknown identity. In this present polyphasic taxonomy study, including genome-based analyses, we discovered that these isolates represent two novel species belonging to the genus Vagococcus. In all phylogenetic analyses, PNs007T was positioned very close to Vagococcus fessus but both the average nucleotide identity (ANI; 89.5â%) and digital DNA-DNA hybridization (dDDH; 38.3â%) values distinguished it as a novel vagococcal species. STAA11T and STAA25 were genetically highly similar (16S rRNA, ANI and dDDH 100â%). The phylogenetic position of STAA11T was adjacent to but out of the cluster containing V. fessus, Vagococcus coleopterorum and PNs007T. According to the ANI (76.2-76.4â%) and dDDH (<22.6â%) values it also represented a novel vagococcal species. Phenotypic characteristics and chemotaxonomic properties of both novel species were typical for vagococci and they contained C16â:â0 (25.5-30.1â%) and C18â:â1 ω9c (67.3-73.0â%) as the major cellular fatty acids. The streptomycin-resistant genotype of STAA11T and STAA25 allowing the growth on streptomycin thallous acetate actidione medium was considered to result from a modification in codon 104 of the rpsL gene leading to P104A substitution. The ability of STAA11T and STAA25 to produce ammonia from arginine separated them from PNs007T, which did not show arginine deiminase activity. We propose the names Vagococcus proximus sp. nov. (type strain PNs007T=DSM 115185T=CCUG 76696T) and Vagococcus intermedius sp. nov. (type strain STAA11T=DSM 115183T=CCUG 76697T) for these novel species.
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Pollos , Ácidos Grasos , Animales , Ácidos Grasos/química , Filogenia , ARN Ribosómico 16S/genética , Composición de Base , Análisis de Secuencia de ADN , ADN Bacteriano/genética , Técnicas de Tipificación Bacteriana , Carne , Enterococcaceae , Hibridación de Ácido Nucleico , AtmósferaRESUMEN
Melissococcus plutonius is a Gram-positive lanceolate coccus that is the causative agent of European foulbrood, an important bacterial disease of honey bee brood. Although this bacterium was originally described in the early 20th century, a culture method for this bacterium was not established until more than 40 years after its discovery due to its fastidious characteristics, including the requirement for high potassium and anaerobic/microaerophilic conditions. These characteristics were considered to be common to the majority of M. plutonius strains isolated worldwide, and M. plutonius was also thought to be genetically homologous or clonal for years. However, non-fastidious variants of this species (designated as atypical M. plutonius) were very recently identified in Japan. Although the morphology of these unusual strains was similar to that of traditionally well-known M. plutonius strains, atypical strains were genetically very different from most of the M. plutonius strains previously isolated and were highly virulent to individual bee larva. These atypical variants were initially considered to be unique to Japan, but were subsequently found worldwide; however, the frequency of isolation varied from country to country. The background of the discovery of atypical M. plutonius in Japan and current knowledge on atypical strains, including their biochemical and culture characteristics, virulence, detection methods, and global distribution, are described in this review. Remaining mysteries related to atypical M. plutonius and directions for future research are also discussed.
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Infecciones Bacterianas , Enterococcaceae , Abejas , Animales , Virulencia , Larva/microbiología , Enterococcaceae/genética , Infecciones Bacterianas/veterinariaRESUMEN
OBJECTIVE: The microbiota of a seasoning sauce fermentation process is usually complex and includes multiple species and even various strains of one species. Moreover, composition and cell numbers of individual strains vary over the course of the entire fermentation. This study demonstrates the applicability of a multiplex PCR system to monitor growth dynamics of Tetragenococcus (T.) halophilus strains in order to evaluate their performance and help to select the most competitive starter strain. RESULTS: In a previous study we isolated T. halophilus strains from multiple lupine moromi fermentation processes and characterized them. In this study we wanted to monitor the growth dynamics of these strains in a competitive lupine moromi model fermentation process using a multiplex PCR system. Therefore, pasteurized lupine koji was inoculated with eight different T. halophilus strains, six from lupine moromi, one from an experimental buckwheat moromi fermentation process and the type strain DSM 20,339T, to create the inoculated lupine moromi pilot scale fermentation process. With the multiplex PCR system, we could detect that all strains could grow in lupine moromi but, that TMW 2.2254 and TMW 2.2264 outperformed all other strains. Both strains dominated the fermentation after three weeks with cell counts between 4 × 106 to 4 × 107 CFU/mL for TMW 2.2254 and 1 × 107 to 5 × 107 CFU/mL for TMW 2.2264. The pH dropped to value below 5 within the first 7 days, the selection of these strains might be related to their acid tolerance.