Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 33.656
Filtrar
1.
Anal Chim Acta ; 1152: 338267, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33648648

RESUMEN

Although SARS-CoV-2 can invade the intestine, though its effect on digestion and absorption is not fully understood. In the present study, 56 COVID-19 patients and 47 age- and sex-matched healthy subjects were divided into a discovery cohort and a validation cohort. Blood, faeces and clinical information were collected from the patients in the hospital and at discharge. The faecal metabolome was analysed using gas chromatography-mass spectrometry, and Spearman's correlation analyses of clinical features, the serum metabolome, and the faecal micro- and mycobiota were conducted. The results showed that, the faeces of COVID-19 patients were enriched with important nutrients that should be metabolized or absorbed, such as sucrose and 2-palmitoyl-glycerol; diet-related components that cannot be synthesized by humans, such as 1,5-anhydroglucitol and D-pinitol; and harmful metabolites, such as oxalate, were also detected. In contrast, purine metabolites such as deoxyinosine and hypoxanthine, low-water-soluble long-chain fatty alcohols/acids such as behenic acid, compounds rarely occurring in nature such as D-allose and D-arabinose, and microbe-related compounds such as 2,4-di-tert-butylphenol were depleted in the faeces of COVID-19 patients. Moreover, these metabolites significantly correlated with altered serum metabolites such as oxalate and gut microbesincluding Ruminococcaceae, Actinomyces, Sphingomonas and Aspergillus. Although levels of several faecal metabolites, such as sucrose, 1,5-anhydroglucitol and D-pinitol, of discharged patients were not different from those of healthy controls (HCs), those of oxalate and 2-palmitoyl-glycerol did differ. Therefore, alterations in the faecal metabolome of COVID-19 patients may reflect malnutrition and intestinal inflammation and warrant greater attention. The results of present study provide new insights into the pathogenesis and treatment of COVID-19.


Asunto(s)
/fisiopatología , Disbiosis/diagnóstico , Heces/química , Microbioma Gastrointestinal/fisiología , Metaboloma/fisiología , Adulto , Bacterias/metabolismo , Estudios de Cohortes , Disbiosis/fisiopatología , Heces/microbiología , Femenino , Hongos/metabolismo , Cromatografía de Gases y Espectrometría de Masas , Humanos , Masculino , Persona de Mediana Edad
2.
Food Chem ; 351: 128454, 2021 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-33652296

RESUMEN

This study aimed to elaborate the roles of salt concentration on doubanjiang (broad bean paste) fermentation. Three sets of doubanjiang samples which had lower salt concentration than commercial doubanjiang were prepared and the physicochemical parameters, biogenic amines, flavor, microbial dynamics were analyzed during fermentation. The salt reduction showed significant effect on the dynamics of bacteria and fungi, thus leading to doubanjiang samples with different properties. Salt reduction during fermentation relieved the osmotic pressure towards microbes, which favored the accumulation of amino acid nitrogen, amino acids, and volatile flavor compounds. However, higher concentrations of total acids and biogenic amines and the existence of conditional pathogens, such as Klebsiella, Cronobacter and Acinetobacter genera, were observed in salt reduced doubanjiang samples, which was undesirable for doubanjiang quality. This study would deep our understanding of the roles of salt on doubanjiang fermentation.


Asunto(s)
Fenómenos Químicos , Fermentación , Cloruro de Sodio Dietético/análisis , Alimentos de Soja/análisis , Alimentos de Soja/microbiología , Gusto , Aminoácidos/metabolismo , Bacterias/metabolismo , Aminas Biogénicas/metabolismo , Hongos/metabolismo
3.
Nat Commun ; 12(1): 1165, 2021 02 19.
Artículo en Inglés | MEDLINE | ID: mdl-33608555

RESUMEN

Animals endemic to deep-sea hydrothermal vents often form obligatory symbioses with bacteria, maintained by intricate host-symbiont interactions. Most genomic studies on holobionts have not investigated both sides to similar depths. Here, we report dual symbiosis in the peltospirid snail Gigantopelta aegis with two gammaproteobacterial endosymbionts: a sulfur oxidiser and a methane oxidiser. We assemble high-quality genomes for all three parties, including a chromosome-level host genome. Hologenomic analyses reveal mutualism with nutritional complementarity and metabolic co-dependency, highly versatile in transporting and using chemical energy. Gigantopelta aegis likely remodels its immune system to facilitate dual symbiosis. Comparisons with Chrysomallon squamiferum, a confamilial snail with a single sulfur-oxidising gammaproteobacterial endosymbiont, show that their sulfur-oxidising endosymbionts are phylogenetically distant. This is consistent with previous findings that they evolved endosymbiosis convergently. Notably, the two sulfur-oxidisers share the same capabilities in biosynthesising nutrients lacking in the host genomes, potentially a key criterion in symbiont selection.


Asunto(s)
Bacterias/genética , Respiraderos Hidrotermales/microbiología , Caracoles/genética , Caracoles/microbiología , Simbiosis/genética , Animales , Bacterias/metabolismo , Gammaproteobacteria/genética , Gammaproteobacteria/metabolismo , Expresión Génica , Genoma Bacteriano , Genómica , Filogenia , Caracoles/metabolismo , Azufre/metabolismo , Simbiosis/fisiología , Transcriptoma
4.
Microbiome ; 9(1): 55, 2021 02 23.
Artículo en Inglés | MEDLINE | ID: mdl-33622394

RESUMEN

BACKGROUND: The intestinal microbiota plays a crucial role in protecting the host from pathogenic microbes, modulating immunity and regulating metabolic processes. We studied the simplified human intestinal microbiota (SIHUMIx) consisting of eight bacterial species with a particular focus on the discovery of novel small proteins with less than 100 amino acids (= sProteins), some of which may contribute to shape the simplified human intestinal microbiota. Although sProteins carry out a wide range of important functions, they are still often missed in genome annotations, and little is known about their structure and function in individual microbes and especially in microbial communities. RESULTS: We created a multi-species integrated proteogenomics search database (iPtgxDB) to enable a comprehensive identification of novel sProteins. Six of the eight SIHUMIx species, for which no complete genomes were available, were sequenced and de novo assembled. Several proteomics approaches including two earlier optimized sProtein enrichment strategies were applied to specifically increase the chances for novel sProtein discovery. The search of tandem mass spectrometry (MS/MS) data against the multi-species iPtgxDB enabled the identification of 31 novel sProteins, of which the expression of 30 was supported by metatranscriptomics data. Using synthetic peptides, we were able to validate the expression of 25 novel sProteins. The comparison of sProtein expression in each single strain versus a multi-species community cultivation showed that six of these sProteins were only identified in the SIHUMIx community indicating a potentially important role of sProteins in the organization of microbial communities. Two of these novel sProteins have a potential antimicrobial function. Metabolic modelling revealed that a third sProtein is located in a genomic region encoding several enzymes relevant for the community metabolism within SIHUMIx. CONCLUSIONS: We outline an integrated experimental and bioinformatics workflow for the discovery of novel sProteins in a simplified intestinal model system that can be generically applied to other microbial communities. The further analysis of novel sProteins uniquely expressed in the SIHUMIx multi-species community is expected to enable new insights into the role of sProteins on the functionality of bacterial communities such as those of the human intestinal tract. Video abstract.


Asunto(s)
Proteínas Bacterianas/análisis , Proteínas Bacterianas/química , Comunicación Celular , Microbioma Gastrointestinal , Bacterias/clasificación , Bacterias/genética , Bacterias/aislamiento & purificación , Bacterias/metabolismo , Proteínas Bacterianas/genética , Microbioma Gastrointestinal/genética , Humanos , Intestinos/química , Intestinos/microbiología , Metagenoma/genética , Espectrometría de Masas en Tándem
5.
Adv Exp Med Biol ; 1275: 323-338, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33539021

RESUMEN

Bacteria are able to inhabit and survive vastly diverse environments. This enormous adaptive capacity depend on their ability to perceive cues from the micro-environment and process this information accordingly to mount appropriate metabolic responses and ultimately sustain homeostasis. From systems perspective, microbial cells conceal significant degree of organismal complexity, which may only be managed by continuous bulk cellular information flow and processing, inside the cell, between other cells and the environment. In this respect, reversible covalent modification of proteins is one of the universal mode of information flow mechanism used to regulate metabolism in all organisms. More than 30 types of post translational modifications have been identified, where phosphorylation constitutes nearly half of them. Bacterial cells possess several modes of phosphoprotein mediated information flow mechanisms. Histidine kinases and two component systems, bacterial tyrosine kinases, Hanks type serine/threonine kinases, atypical serine kinases and arginine kinases have been identified in many species.


Asunto(s)
Proteínas Bacterianas , Proteínas Quinasas , Bacterias/genética , Bacterias/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Fosforilación , Proteínas Quinasas/genética , Proteínas Quinasas/metabolismo , Procesamiento Proteico-Postraduccional , Proteínas Serina-Treonina Quinasas/metabolismo
6.
J Leukoc Biol ; 109(3): 519-533, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33630384

RESUMEN

In 1908, Ilya Metchnikov, then Assistant director of the Pasteur Institute, writes about the potential of bacterial cultures to remedy a range of intestinal ailments. Translated from French.


Asunto(s)
Bacterias/metabolismo , Enfermedades Intestinales/microbiología , Enfermedades Intestinales/terapia , Intestinos/microbiología , Animales , Investigación Empírica , Historia del Siglo XX , Humanos , Leche/microbiología
7.
Food Chem ; 349: 129131, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33581434

RESUMEN

Soy sauce is a traditional fermented soy food for enhancing the umami taste in Asian cuisines. In this study, 16S rRNA gene throughput sequencing analysis showed the bacterial communities and the changes in soy sauce during fermentation. Weissella, Bacillus and Lactococcus were the most abundant at genus level. The uncultured bacterium Weissella and Lactococcus had relatively high abundance at species level. Alpha diversity analysis indicated the bacterial community diversity increased at fermentation initiation, while decreased as fermentation progressed. Based on beta-diversity analysis, four clusters including cluster I (time point A-F), cluster II (G,H), cluster III (I,J) and cluster IV(K) were distinctly separated, indicating the fermentation time significantly affected bacterial community diversity. Also, close associations were found between the bacterial communities in soy sauce and its amino acid nitrogen, organic acid and reducing sugar contents during fermentation. Therefore, it will provide important information for optimization of the soy sauce production process.


Asunto(s)
Aminoácidos/análisis , Bacterias/genética , Fermentación , Secuenciación de Nucleótidos de Alto Rendimiento , Alimentos de Soja/análisis , Alimentos de Soja/microbiología , Azúcares/análisis , Aminoácidos/química , Bacterias/aislamiento & purificación , Bacterias/metabolismo , Nitrógeno/química , ARN Ribosómico 16S/genética , Gusto
8.
Sci Data ; 8(1): 51, 2021 02 09.
Artículo en Inglés | MEDLINE | ID: mdl-33563990

RESUMEN

Acetogens are anaerobic bacteria that utilise gaseous feedstocks such as carbon monoxide (CO) and carbon dioxide (CO2) to synthesise biomass and various metabolites via the energetically efficient Wood-Ljungdahl pathway. Because of this pathway, acetogens have been considered as a novel platform to produce biochemicals from gaseous feedstocks, potentially replacing the conventional thermochemical processes. Despite their advantages, a lack of systematic understanding of the transcriptional and translational regulation in acetogens during autotrophic growth limits the rational strain design to produce the desired products. To overcome this problem, we presented RNA sequencing and ribosome profiling data of four acetogens cultivated under heterotrophic and autotrophic conditions, providing data on genome-scale transcriptional and translational responses of acetogens during CO2 fixation. These data facilitate the discovery of regulatory elements embedded in their genomes, which could be utilised to engineer strains to achieve better growth and productivity. We anticipate that these data will expand our understanding of the processes of CO2 fixation and will help in the designing of strains for the desired biochemical production.


Asunto(s)
Procesos Autotróficos , Bacterias/metabolismo , Dióxido de Carbono/metabolismo , Procesos Heterotróficos , Transcriptoma , Ciclo del Carbono , RNA-Seq
9.
J Chromatogr A ; 1639: 461924, 2021 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-33545579

RESUMEN

Modular virus-like particles and capsomeres are potential vaccine candidates that can induce strong immune responses. There are many described protocols for the purification of microbially-produced viral protein in the literature, however, they suffer from inherent limitations in efficiency, scalability and overall process costs. In this study, we investigated alternative purification pathways to identify and optimise a suitable purification pathway to overcome some of the current challenges. Among the methods, the optimised purification strategy consists of an anion exchange step in flow through mode followed by a multi modal cation exchange step in bind and elute mode. This approach allows an integrated process without any buffer adjustment between the purification steps. The major contaminants like host cell proteins, DNA and aggregates can be efficiently removed by the optimised strategy, without the need for a size exclusion polishing chromatography step, which otherwise could complicate the process scalability and increase overall cost. High throughput process technology studies were conducted to optimise binding and elution conditions for multi modal cation exchanger, Capto™ MMC and strong anion exchanger Capto™ Q. A dynamic binding capacity of 14 mg ml-1 was achieved for Capto™ MMC resin. Samples derived from each purification process were thoroughly characterized by RP-HPLC, SEC-HPLC, SDS-PAGE and LC-ESI-MS/MS Mass Spectrometry analytical methods. Modular polyomavirus major capsid protein could be purified within hours using the optimised process achieving purities above 87% and above 96% with inclusion of an initial precipitation step. Purified capsid protein could be easily assembled in-vitro into well-defined virus-like particles by lowering pH with addition of calcium chloride to the eluate. High throughout studies allowed the screening of a vast design space within weeks, rather than months, and unveiled complicated binding behaviour for CaptoTM MMC.


Asunto(s)
Bacterias/metabolismo , Proteínas de la Cápside/aislamiento & purificación , Cromatografía en Gel/métodos , Unión Proteica , Espectrometría de Masas en Tándem , Virión/ultraestructura
10.
Ecotoxicol Environ Saf ; 214: 112084, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33640726

RESUMEN

Direct Black G (DBG) is a highly toxic synthetic azo dye which is difficult to degrade. Biological treatment seems to be a promising option for the treatment of azo dye containing effluent. A thermophilic bacterial strain (Anoxybacillus sp. PDR2) previously isolated from the soil can effectively remove DBG. However, the molecular underpinnings of DBG degradation and the microbial detoxification ability remains unknown. In the present study, the genetic background of PDR2 for the efficient degradation of DBG and its adaptation to azo dye-contaminated environments was revealed by bioinformatics. Moreover, the possible biodegradation pathways were speculated based on the UV-vis spectral analysis, FTIR, and intermediates identified by LC-MS. Additionally, phytotoxicity and the comet experiment studies clearly indicated that PDR2 converts toxic azo dye (DBG) into low toxicity metabolites. The combination of biodegradation pathways and detoxification analysis were utilized to explore the molecular degradation mechanism and bioremediation of azo dye for future applications. These findings will provide a valuable theoretical basis for the practical treatment of azo dye wastewater.


Asunto(s)
Anoxybacillus/metabolismo , Compuestos Azo/metabolismo , Biodegradación Ambiental , Anoxybacillus/genética , Bacterias/metabolismo , Color , Colorantes/metabolismo , Humanos , Suelo , Aguas Residuales
11.
Methods Mol Biol ; 2246: 87-96, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33576984

RESUMEN

Oligonucleotides able to hybridize bacterial RNA via in situ hybridization may potentially act as new antimicrobials, replacing antibiotics, and as fast in vivo diagnostic probes, outperforming current clinical methodologies. Nonetheless, oligonucleotides are not able to efficiently permeate the multi-layered bacterial envelope to reach their target RNA in the cytosol. Cationic fusogenic liposomes are here suggested as vehicles to enable the internalization of oligonucleotides in bacteria. Here, we describe the formulation of DOTAP-DOPE liposomes, their complexation with small negatively charged oligonucleotides, and the evaluation of the intracellular delivery of the oligonucleotides in bacteria. This strategy uncovers the potential of performing FISH in vivo for real-time detection and treatment of infections.


Asunto(s)
Bacterias/metabolismo , Liposomas/química , Oligonucleótidos/metabolismo , Cationes/química , Citosol/metabolismo , Ácidos Grasos Monoinsaturados/química , Hibridación Fluorescente in Situ/métodos , Fosfatidiletanolaminas/química , Compuestos de Amonio Cuaternario/química , ARN Bacteriano/metabolismo
12.
Microbiome ; 9(1): 43, 2021 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-33583433

RESUMEN

BACKGROUND: Chitin ranks as the most abundant polysaccharide in the oceans yet knowledge of shifts in structure and diversity of chitin-degrading communities across marine niches is scarce. Here, we integrate cultivation-dependent and -independent approaches to shed light on the chitin processing potential within the microbiomes of marine sponges, octocorals, sediments, and seawater. RESULTS: We found that cultivatable host-associated bacteria in the genera Aquimarina, Enterovibrio, Microbulbifer, Pseudoalteromonas, Shewanella, and Vibrio were able to degrade colloidal chitin in vitro. Congruent with enzymatic activity bioassays, genome-wide inspection of cultivated symbionts revealed that Vibrio and Aquimarina species, particularly, possess several endo- and exo-chitinase-encoding genes underlying their ability to cleave the large chitin polymer into oligomers and dimers. Conversely, Alphaproteobacteria species were found to specialize in the utilization of the chitin monomer N-acetylglucosamine more often. Phylogenetic assessments uncovered a high degree of within-genome diversification of multiple, full-length endo-chitinase genes for Aquimarina and Vibrio strains, suggestive of a versatile chitin catabolism aptitude. We then analyzed the abundance distributions of chitin metabolism-related genes across 30 Illumina-sequenced microbial metagenomes and found that the endosymbiotic consortium of Spongia officinalis is enriched in polysaccharide deacetylases, suggesting the ability of the marine sponge microbiome to convert chitin into its deacetylated-and biotechnologically versatile-form chitosan. Instead, the abundance of endo-chitinase and chitin-binding protein-encoding genes in healthy octocorals leveled up with those from the surrounding environment but was found to be depleted in necrotic octocoral tissue. Using cultivation-independent, taxonomic assignments of endo-chitinase encoding genes, we unveiled previously unsuspected richness and divergent structures of chitinolytic communities across host-associated and free-living biotopes, revealing putative roles for uncultivated Gammaproteobacteria and Chloroflexi symbionts in chitin processing within sessile marine invertebrates. CONCLUSIONS: Our findings suggest that differential chitin degradation pathways, utilization, and turnover dictate the processing of chitin across marine micro-niches and support the hypothesis that inter-species cross-feeding could facilitate the co-existence of chitin utilizers within marine invertebrate microbiomes. We further identified chitin metabolism functions which may serve as indicators of microbiome integrity/dysbiosis in corals and reveal putative novel chitinolytic enzymes in the genus Aquimarina that may find applications in the blue biotechnology sector. Video abstract.


Asunto(s)
Organismos Acuáticos/microbiología , Bacterias/metabolismo , Quitina/metabolismo , Sedimentos Geológicos/microbiología , Metagenómica , Microbiota , Agua de Mar/microbiología , Animales , Antozoos/microbiología , Bacterias/enzimología , Bacterias/genética , Quitinasas/genética , Quitinasas/metabolismo , Microbiota/genética , Océanos y Mares , Filogenia , Poríferos/microbiología , Simbiosis
13.
Microbiome ; 9(1): 46, 2021 02 16.
Artículo en Inglés | MEDLINE | ID: mdl-33593438

RESUMEN

BACKGROUND: The sulfur cycle encompasses a series of complex aerobic and anaerobic transformations of S-containing molecules and plays a fundamental role in cellular and ecosystem-level processes, influencing biological carbon transfers and other biogeochemical cycles. Despite their importance, the microbial communities and metabolic pathways involved in these transformations remain poorly understood, especially for inorganic sulfur compounds of intermediate oxidation states (thiosulfate, tetrathionate, sulfite, polysulfides). Isolated and highly stratified, the extreme geochemical and environmental features of meromictic ice-capped Lake A, in the Canadian High Arctic, provided an ideal model ecosystem to resolve the distribution and metabolism of aquatic sulfur cycling microorganisms along redox and salinity gradients. RESULTS: Applying complementary molecular approaches, we identified sharply contrasting microbial communities and metabolic potentials among the markedly distinct water layers of Lake A, with similarities to diverse fresh, brackish and saline water microbiomes. Sulfur cycling genes were abundant at all depths and covaried with bacterial abundance. Genes for oxidative processes occurred in samples from the oxic freshwater layers, reductive reactions in the anoxic and sulfidic bottom waters and genes for both transformations at the chemocline. Up to 154 different genomic bins with potential for sulfur transformation were recovered, revealing a panoply of taxonomically diverse microorganisms with complex metabolic pathways for biogeochemical sulfur reactions. Genes for the utilization of sulfur cycle intermediates were widespread throughout the water column, co-occurring with sulfate reduction or sulfide oxidation pathways. The genomic bin composition suggested that in addition to chemical oxidation, these intermediate sulfur compounds were likely produced by the predominant sulfur chemo- and photo-oxidisers at the chemocline and by diverse microbial degraders of organic sulfur molecules. CONCLUSIONS: The Lake A microbial ecosystem provided an ideal opportunity to identify new features of the biogeochemical sulfur cycle. Our detailed metagenomic analyses across the broad physico-chemical gradients of this permanently stratified lake extend the known diversity of microorganisms involved in sulfur transformations over a wide range of environmental conditions. The results indicate that sulfur cycle intermediates and organic sulfur molecules are major sources of electron donors and acceptors for aquatic and sedimentary microbial communities in association with the classical sulfur cycle. Video abstract.


Asunto(s)
Bacterias/genética , Bacterias/metabolismo , Ecosistema , Lagos/microbiología , Metagenoma , Azufre/metabolismo , Organismos Acuáticos/genética , Organismos Acuáticos/metabolismo , Canadá , Oxidación-Reducción
14.
Ecotoxicol Environ Saf ; 213: 112054, 2021 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-33601170

RESUMEN

Spent mushroom compost (SMC) is a lignocellulose-rich waste material commonly used in the passive treatment of heavy metal-contaminated environments. In this study, we investigated the bioremediation potential of SMC against an inorganic form of arsenic, examining the individual abiotic and biotic transformations carried out by SMC. We demonstrated, that key SMC physiological groups of bacteria (denitrifying, cellulolytic, sulfate-reducing, and heterotrophic) are resistant to arsenites and arsenates, while the microbial community in SMC is also able to oxidize As(III) and reduce As(V) in respiratory metabolisms, although the SMC did not contain any As. We showed, that cooperation between arsenate and sulfate-reducing bacteria led to the precipitation of AsxSy. We also found evidence of the significant role organic acids may play in arsenic complexation, and we demonstrated the occurrence of As-binding proteins in the SMC. Furthermore, we confirmed, that biofilm produced by the microbial community in SMC was able to trap As(V) ions. We postulated, that the above-mentioned transformations are responsible for the sorption efficiency of As(V) (up to 25%) and As(III) (up to 16%), as well as the excellent buffering properties of SMC observed in the sorption experiments.


Asunto(s)
Agaricales/metabolismo , Arsénico/metabolismo , Biodegradación Ambiental , Compostaje , Arseniatos , Arsénico/análisis , Arsenitos/metabolismo , Bacterias/metabolismo , Biotransformación , Metales Pesados/metabolismo , Oxidación-Reducción
15.
Food Chem ; 348: 129083, 2021 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-33517000

RESUMEN

In this study, three potential probiotic strains were selected to ferment blueberry and blackberry juices. The viable cell counts of selected strains were increased by 0.4-0.7 log CFU/mL in berry juices environments after 48-h fermentation. Meanwhile, the contents of cyanindin-3-glucoside and peonidin-3-glucoside decreased over 30%. Heatmap presented an upgrade trend of syringic acid, ferulic acid, gallic acid and lactic acid during fermentation. However, the contents of p-coumaric acid, protocatechuic acid, chlorogenic acid, critic acid and malic acid showed downgrade trend. The metabolism of phenolics probably contributed to the enhancement of the ABTS radical scavenging activity (40%-60%) in fermented berry juices. Moreover, the three strains presented different capacities on changing the quality of berry juices according to the PCA and LDA analysis. The contents of individual organic acids had positive correlations with sensory quality, especially for sourness. Overall, probiotic fermentation could improve the sensory quality of berry juices.


Asunto(s)
Bacterias/metabolismo , Arándanos Azules (Planta)/química , Fermentación , Jugos de Frutas y Vegetales/microbiología , Fenoles/análisis , Probióticos/metabolismo , Rubus/química , Antioxidantes/análisis , Bifidobacterium bifidum/metabolismo , Frutas/química , Jugos de Frutas y Vegetales/análisis , Humanos , Lactobacillus plantarum/metabolismo , Streptococcus thermophilus/metabolismo , Gusto
16.
Ecotoxicol Environ Saf ; 210: 111831, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33388591

RESUMEN

The effects of bioaugmentation with immobilized Penicillium restrictum on the removal efficiency of sulfamethoxazole (SMX), erythromycin (ERY) and tetracycline (TC) antibiotics as well as membrane biofouling was studied using hollow-fiber membrane bioreactor (HF-MBR). Bioaugmentation with P. restrictum led to a significant change in the antibiotic removal efficiency and relative abundance of aerobic microbial community, most probably as a result of its quorum quenching activity. Furthermore, in addition to its role in the increase of SMX and ERY removal efficiencies and the decrease of their sorption on solid phase, bioaugmentation significantly reduced the transmembrane pressure which in turn reduced membrane clogging. The most abundant phyla in sludge and biofilm samples in the presence of P. restrictum were observed to be Proteobacteria, Bacteroidetes and Firmicutes. Differences in bacterial compositions and their specificity in biodegradation of antibiotics in different reactors showed that bacteria were specifically selected under the pressure of antibiotics and growing fungus.


Asunto(s)
Antibacterianos/metabolismo , Reactores Biológicos/microbiología , Penicillium/fisiología , Bacterias/metabolismo , Biodegradación Ambiental , Biopelículas , Incrustaciones Biológicas , Eritromicina/metabolismo , Membranas Artificiales , Microbiota , Percepción de Quorum , Sulfametoxazol/metabolismo , Tetraciclina/metabolismo , Aguas Residuales/microbiología
17.
Ecotoxicol Environ Saf ; 212: 111970, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33517034

RESUMEN

In this study, a taxonomic and functional metagenomic method was used to investigate the difference produced between degrading bacteria immobilized in layer-by-layer assembly (LBL) microcapsules or not during the bioremediation of a soil polluted with phenanthrene (PHE). Bioaugmentation with LBL microcapsule immobilized degrading bacteria could result in different changes of native microbial communities, shifting the functional gene constructions of polluted soils. The LBL treatment enhanced PHE degradation (initial concentration of 100 mg kg-1 dry soil) by 60% after 25 d compared to the free bacteria (FB). The enhancing effect of PHE degradation produced by the LBL treatment was found to be significantly associated with some crucial phyla (e.g., Bacteroides, Gemmatimonadetes and Acidobacteria) and genera including Streptomyces, Ramlibacter, Mycobacterium, Phycicoccus, Gemmatirosa, Flavisolibacter, Micromonospora, Acid_Candidatus_Koribacter and Gemmatimonas. The main differences of functional metagenomics between LBL and FB treatments were observed in higher levels in metabolism of aromatic hydrocarbons and its related functions or enzymes in the former, e.g., membrane transport systems, binding, substrate transporter, cleavage enzymes, dehydrogenation, oxidase, esterase and glycosidase, greatly favoring PHE mineralization. Therefore, our results provide useful findings on understanding of how immobilization strategies can influence the taxonomic and functional gene composition in soils, as well as polycyclic aromatic hydrocarbons (PAH) degradation.


Asunto(s)
Biodegradación Ambiental , Fenantrenos/metabolismo , Microbiología del Suelo , Contaminantes del Suelo/metabolismo , Bacterias/metabolismo , Cápsulas/metabolismo , Contaminantes Ambientales/metabolismo , Metagenómica , Microbiota , Hidrocarburos Policíclicos Aromáticos/análisis , Suelo/química , Contaminantes del Suelo/análisis
18.
Viruses ; 13(1)2021 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-33435393

RESUMEN

The bacteriophage T4 early gene product MotB binds tightly but nonspecifically to DNA, copurifies with the host Nucleoid Associated Protein (NAP) H-NS in the presence of DNA and improves T4 fitness. However, the T4 transcriptome is not significantly affected by a motB knockdown. Here we have investigated the phylogeny of MotB and its predicted domains, how MotB and H-NS together interact with DNA, and how heterologous overexpression of motB impacts host gene expression. We find that motB is highly conserved among Tevenvirinae. Although the MotB sequence has no homology to proteins of known function, predicted structure homology searches suggest that MotB is composed of an N-terminal Kyprides-Onzonis-Woese (KOW) motif and a C-terminal DNA-binding domain of oligonucleotide/oligosaccharide (OB)-fold; either of which could provide MotB's ability to bind DNA. DNase I footprinting demonstrates that MotB dramatically alters the interaction of H-NS with DNA in vitro. RNA-seq analyses indicate that expression of plasmid-borne motB up-regulates 75 host genes; no host genes are down-regulated. Approximately 1/3 of the up-regulated genes have previously been shown to be part of the H-NS regulon. Our results indicate that MotB provides a conserved function for Tevenvirinae and suggest a model in which MotB functions to alter the host transcriptome, possibly by changing the association of H-NS with the host DNA, which then leads to conditions that are more favorable for infection.


Asunto(s)
Bacterias/metabolismo , Bacterias/virología , Proteínas Bacterianas/metabolismo , Bacteriófago T4/genética , Proteínas de Unión al ADN/metabolismo , Expresión Génica , Genes Virales , Interacciones Huésped-Patógeno , Proteínas Bacterianas/química , Secuencia de Bases , Proteínas de Unión al ADN/química , Filogenia , Fagos T/genética
19.
Yi Chuan ; 43(1): 66-73, 2021 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-33509775

RESUMEN

In bacteria, GntR family transcription regulators are the widespread family of transcription factors. Members of this family consist of two functional domains, a conserved N-terminal DNA-binding domain that contains a typical helix-turn-helix (HTH) motif and a C-terminal effector-binding or oligomerization domain. Usually, the amino acid sequences of N-terminal DNA-binding domains are highly conserved, but differ in the C-terminal effector-binding or oligomerization domains. In the past several decades, many GntR family transcription regulators have been characterized in a number of bacteria. These regulators control a variety of cellular processes such as cell motility, glucose metabolism, bacterial resistance, pathogenesis and virulence. In this review, we summarized the discovery, C-terminal domains, biological function and regulation mode of GntR family transcription regulators. This review will help researchers to obtain more knowledge about the functions and mechanisms of the GntR family transcriptional regulatory factors.


Asunto(s)
Bacterias/genética , Proteínas Bacterianas , Proteínas de Unión al ADN , Secuencias Hélice-Giro-Hélice , Factores de Transcripción/genética , Bacterias/metabolismo , Proteínas Bacterianas/genética , Proteínas de Unión al ADN/genética , Regulación Bacteriana de la Expresión Génica
20.
Artículo en Inglés | MEDLINE | ID: mdl-33470889

RESUMEN

In this study, we investigated the interaction of submicron-sized bioplastics with environmentally and clinically important bacteria under seawater and sediment conditions. To examine the relationship between submicron-sized bioplastics and bacteria in seawater and sediment, we focused on the bacterial activation and their biochemical key events toward the protein, carbohydrate, lipid, and antioxidant response. In addition, culture-dependent biofilm formation on submicron-sized bioplastics and their characterization was performed. The results indicated that selected bacteria increased their viability both in seawater and sediment with the submicron-sized bioplastics in that the bioplastics decreased their mass at the level of 10-23%. However, the activation level and mechanism affected the polymer type, bacteria, and environmental media, and submicron-sized bioplastics promoted biofilm formation with enhancing basophilic characteristics of biofilms.


Asunto(s)
Sedimentos Geológicos/microbiología , Microplásticos/análisis , Polímeros/análisis , Agua de Mar/microbiología , Contaminantes Químicos del Agua/análisis , Bacterias/efectos de los fármacos , Bacterias/metabolismo , Biodegradación Ambiental , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Sedimentos Geológicos/química , Viabilidad Microbiana/efectos de los fármacos , Microplásticos/toxicidad , Tamaño de la Partícula , Polímeros/metabolismo , Polímeros/toxicidad , Agua de Mar/química , Microbiología del Agua , Contaminantes Químicos del Agua/toxicidad
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...