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1.
BMC Bioinformatics ; 21(Suppl 14): 367, 2020 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-32998698

RESUMO

BACKGROUND: Essential genes are those genes that are critical for the survival of an organism. The prediction of essential genes in bacteria can provide targets for the design of novel antibiotic compounds or antimicrobial strategies. RESULTS: We propose a deep neural network for predicting essential genes in microbes. Our architecture called DEEPLYESSENTIAL makes minimal assumptions about the input data (i.e., it only uses gene primary sequence and the corresponding protein sequence) to carry out the prediction thus maximizing its practical application compared to existing predictors that require structural or topological features which might not be readily available. We also expose and study a hidden performance bias that effected previous classifiers. Extensive results show that DEEPLYESSENTIAL outperform existing classifiers that either employ down-sampling to balance the training set or use clustering to exclude multiple copies of orthologous genes. CONCLUSION: Deep neural network architectures can efficiently predict whether a microbial gene is essential (or not) using only its sequence information.


Assuntos
Bactérias/genética , Genes Essenciais , Redes Neurais de Computação , Área Sob a Curva , Análise por Conglomerados , Códon , Bactérias Gram-Negativas/genética , Bactérias Gram-Positivas/genética , Curva ROC
2.
Curr Biol ; 30(19): R1124-R1130, 2020 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-33022254

RESUMO

Since the first recognition that infectious microbes serve as the causes of many human diseases, physicians and scientists have sought to understand and control their spread. For the past 150+ years, these 'microbe hunters' have learned to combine epidemiological information with knowledge of the infectious agent(s). In this essay, I reflect on the evolution of microbe hunting, beginning with the history of pre-germ theory epidemiological studies, through the microbiological and molecular eras. Now in the genomic age, modern-day microbe hunters are combining pathogen whole-genome sequencing with epidemiological data to enhance epidemiological investigations, advance our understanding of the natural history of pathogens and drivers of disease, and ultimately reshape our plans and priorities for global disease control and eradication. Indeed, as we have seen during the ongoing Covid-19 pandemic, the role of microbe hunters is now more important than ever. Despite the advances already made by microbial genomic epidemiology, the field is still maturing, with many more exciting developments on the horizon.


Assuntos
Bactérias/genética , Infecções Bacterianas/diagnóstico , Infecções Bacterianas/epidemiologia , Epidemiologia Molecular/métodos , Prevenção Primária/métodos , Bactérias/patogenicidade , Betacoronavirus/genética , Betacoronavirus/patogenicidade , Infecções por Coronavirus/epidemiologia , Genoma Bacteriano/genética , Genoma Viral/genética , História do Século XIX , História do Século XX , Humanos , Microbiota/genética , Pandemias , Pneumonia Viral/epidemiologia
3.
Water Sci Technol ; 82(6): 1142-1154, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33055404

RESUMO

Microbial consortia are effective biofilters to treat wastewaters, allowing for resource recovery and water remediation. To reuse and save water in the domestic cycle, we assembled a suspended biofilm, a 'biofilter' to treat dishwasher wastewater. Bacterial monocultures of both photo- and heterotrophs were assembled in an increasingly complex fashion to test their nutrient stripping capacity. This 'biofilter' is the core of an integrated system (Zero Mile System) devoted to reusing and upcycling of reconditioned wastewater, partly in subsequent dishwasher cycles and partly into a vertical garden for plant food cultivation. The biofilter was assembled based on a strain of the photosynthetic, filamentous cyanobacterium Trichormus variabilis, selected to produce an oxygen evolving scaffold, and three heterotrophic aerobic bacterial isolates coming from the dishwasher wastewater itself: Acinetobacter, Exiguobacterium and Pseudomonas spp. The consortium was constructed starting with 16 isolates tested one-to-one with T. variabilis and then selecting the heterotrophic microbes up to a final one-to-three consortium, which included two dominant and a rare component of the wastewater community. This consortium thrives in the wastewater much better than T. variabilis alone, efficiently stripping N and P in short time, a pivotal step for the reuse and saving of water in household appliances.


Assuntos
Águas Residuárias , Purificação da Água , Bactérias/genética , Consórcios Microbianos , Nutrientes
4.
J Environ Qual ; 49(1): 210-219, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33016351

RESUMO

Reed canary grass (Phalaris arundinacea L.) is an invasive, cool-season grass commonly dominating wetlands with high nutrient loads. Its impact on nitrogen removal via denitrification in wetlands is unknown. Most studies of denitrification in treatment wetlands have focused on the effects of physical or chemical variables and not on the effects of plant roots on the soil environment. The purpose of this study was to measure effects of plant type on denitrification rates in typical wetland soils of the midwestern United States by comparing wet prairie mix, switchgrass-dominated, and reed canary grass plant communities. Nitrate (NO3 - ) removal and other parameters were measured in miniature wetlands, or mesocosms, containing each plant community transplanted from a small agricultural treatment wetland in southern Minnesota. Quantitative polymerase chain reaction analysis was used to quantify the total bacteria population (measured with 16S rRNA genes) and denitrifying gene abundance (measured with nosZ genes) from the rhizosphere of each plant community. The wet prairie mix mesocosms on average removed the most NO3 - in each test (p = .01 and .08). Whereas the wet prairie mix removed the most NO3 - from the surface water (p < .01), reed canary grass removed more from the subsurface (p < .01). Ratios of denitrifying to total bacteria were higher in the wet prairie mix than in the other communities' root zones (p < .05). Results suggest that reed canary grass invasion could reduce denitrification in wetlands, especially during the spring and fall when it is growing but other plants are dormant.


Assuntos
Bactérias/genética , Áreas Alagadas , Meio-Oeste dos Estados Unidos , Minnesota , RNA Ribossômico 16S
5.
Nat Commun ; 11(1): 4982, 2020 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-33020474

RESUMO

Nonalcoholic fatty liver disease (NAFLD) is associated with obesity but also found in non-obese individuals. Gut microbiome profiles of 171 Asians with biopsy-proven NAFLD and 31 non-NAFLD controls are analyzed using 16S rRNA sequencing; an independent Western cohort is used for external validation. Subjects are classified into three subgroups according to histological spectra of NAFLD or fibrosis severity. Significant alterations in microbiome diversity are observed according to fibrosis severity in non-obese, but not obese, subjects. Ruminococcaceae and Veillonellaceae are the main microbiota associated with fibrosis severity in non-obese subjects. Furthermore, stool bile acids and propionate are elevated, especially in non-obese subjects with significant fibrosis. Fibrosis-related Ruminococcaceae and Veillonellaceae species undergo metagenome sequencing, and four representative species are administered in three mouse NAFLD models to evaluate their effects on liver damage. This study provides the evidence for the role of the microbiome in the liver fibrosis pathogenesis, especially in non-obese subjects.


Assuntos
Bactérias/isolamento & purificação , Microbioma Gastrointestinal/fisiologia , Hepatopatia Gordurosa não Alcoólica/microbiologia , Hepatopatia Gordurosa não Alcoólica/patologia , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/metabolismo , Ácidos e Sais Biliares/análise , Ácidos e Sais Biliares/metabolismo , Biomarcadores , Fezes/química , Fezes/microbiologia , Fibrose , Microbioma Gastrointestinal/genética , Humanos , Cirrose Hepática/diagnóstico , Cirrose Hepática/metabolismo , Cirrose Hepática/microbiologia , Cirrose Hepática/patologia , Camundongos , Hepatopatia Gordurosa não Alcoólica/metabolismo , Obesidade/metabolismo , Obesidade/microbiologia , Obesidade/patologia , Propionatos/análise , Propionatos/metabolismo , RNA Ribossômico 16S/genética , Reprodutibilidade dos Testes
6.
Nat Commun ; 11(1): 4708, 2020 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-32948758

RESUMO

While the field of microbiology has adapted to the study of complex microbiomes via modern meta-omics techniques, we have not updated our basic knowledge regarding the quantitative levels of DNA, RNA and protein molecules within a microbial cell, which ultimately control cellular function. Here we report the temporal measurements of absolute RNA and protein levels per gene within a mixed bacterial-archaeal consortium. Our analysis of this data reveals an absolute protein-to-RNA ratio of 102-104 for bacterial populations and 103-105 for an archaeon, which is more comparable to Eukaryotic representatives' humans and yeast. Furthermore, we use the linearity between the metaproteome and metatranscriptome over time to identify core functional guilds, hence using a fundamental biological feature (i.e., RNA/protein levels) to highlight phenotypical complementarity. Our findings show that upgrading multi-omic toolkits with traditional absolute measurements unlocks the scaling of core biological questions to dynamic and complex microbiomes, creating a deeper insight into inter-organismal relationships that drive the greater community function.


Assuntos
Microbiota/genética , Microbiota/fisiologia , Proteínas/genética , Proteínas/metabolismo , RNA/genética , RNA/metabolismo , Archaea/genética , Archaea/metabolismo , Bactérias/genética , Bactérias/metabolismo , DNA , Perfilação da Expressão Gênica , Genoma Microbiano , Humanos , Metabolômica , Fenótipo , Proteoma , Proteômica , Transcriptoma , Leveduras
7.
Nat Commun ; 11(1): 4635, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32934239

RESUMO

Providing insight into one's health status from a gut microbiome sample is an important clinical goal in current human microbiome research. Herein, we introduce the Gut Microbiome Health Index (GMHI), a biologically-interpretable mathematical formula for predicting the likelihood of disease independent of the clinical diagnosis. GMHI is formulated upon 50 microbial species associated with healthy gut ecosystems. These species are identified through a multi-study, integrative analysis on 4347 human stool metagenomes from 34 published studies across healthy and 12 different nonhealthy conditions, i.e., disease or abnormal bodyweight. When demonstrated on our population-scale meta-dataset, GMHI is the most robust and consistent predictor of disease presence (or absence) compared to α-diversity indices. Validation on 679 samples from 9 additional studies results in a balanced accuracy of 73.7% in distinguishing healthy from non-healthy groups. Our findings suggest that gut taxonomic signatures can predict health status, and highlight how data sharing efforts can provide broadly applicable discoveries.


Assuntos
Bactérias/isolamento & purificação , Microbioma Gastrointestinal , Nível de Saúde , Bactérias/classificação , Bactérias/genética , Fezes/microbiologia , Humanos , Metagenoma , Microbiota
8.
PLoS Comput Biol ; 16(9): e1008159, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32925923

RESUMO

Intracellular spatial heterogeneity is frequently observed in bacteria, where the chromosome occupies part of the cell's volume and a circuit's DNA often localizes within the cell. How this heterogeneity affects core processes and genetic circuits is still poorly understood. In fact, commonly used ordinary differential equation (ODE) models of genetic circuits assume a well-mixed ensemble of molecules and, as such, do not capture spatial aspects. Reaction-diffusion partial differential equation (PDE) models have been only occasionally used since they are difficult to integrate and do not provide mechanistic understanding of the effects of spatial heterogeneity. In this paper, we derive a reduced ODE model that captures spatial effects, yet has the same dimension as commonly used well-mixed models. In particular, the only difference with respect to a well-mixed ODE model is that the association rate constant of binding reactions is multiplied by a coefficient, which we refer to as the binding correction factor (BCF). The BCF depends on the size of interacting molecules and on their location when fixed in space and it is equal to unity in a well-mixed ODE model. The BCF can be used to investigate how spatial heterogeneity affects the behavior of core processes and genetic circuits. Specifically, our reduced model indicates that transcription and its regulation are more effective for genes located at the cell poles than for genes located on the chromosome. The extent of these effects depends on the value of the BCF, which we found to be close to unity. For translation, the value of the BCF is always greater than unity, it increases with mRNA size, and, with biologically relevant parameters, is substantially larger than unity. Our model has broad validity, has the same dimension as a well-mixed model, yet it incorporates spatial heterogeneity. This simple-to-use model can be used to both analyze and design genetic circuits while accounting for spatial intracellular effects.


Assuntos
Bactérias , Redes Reguladoras de Genes/genética , Genes Bacterianos/genética , Modelos Biológicos , Bactérias/química , Bactérias/citologia , Bactérias/genética , Biologia Computacional , Difusão , Espaço Intracelular/química , Espaço Intracelular/genética
9.
Nat Commun ; 11(1): 4827, 2020 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-32973167

RESUMO

In bacteria, translation re-initiation is crucial for synthesizing proteins encoded by genes that are organized into operons. The mechanisms regulating translation re-initiation remain, however, poorly understood. We now describe the ribosome termination structure (RTS), a conserved and stable mRNA secondary structure localized immediately downstream of stop codons, and provide experimental evidence for its role in governing re-initiation efficiency in a synthetic Escherichia coli operon. We further report that RTSs are abundant, being associated with 18%-65% of genes in 128 analyzed bacterial genomes representing all phyla, and are selectively depleted when translation re-initiation is advantageous yet selectively enriched so as to insulate translation when re-initiation is deleterious. Our results support a potentially universal role for the RTS in controlling translation termination-insulation and re-initiation across bacteria.


Assuntos
Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica , Óperon/genética , RNA Mensageiro/química , RNA Mensageiro/fisiologia , Bactérias/classificação , Bactérias/genética , Códon de Terminação/metabolismo , Escherichia coli/metabolismo , Genes Bacterianos/genética , Iniciação Traducional da Cadeia Peptídica , Estrutura Secundária de Proteína , RNA Mensageiro/genética , Ribossomos/metabolismo
10.
Nat Commun ; 11(1): 4887, 2020 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-32985497

RESUMO

The rise in the availability of bacterial genomes defines a need for synthesis: abstracting from individual taxa, to see larger patterns of bacterial lifestyles across systems. A key concept for such synthesis in ecology is the niche, the set of capabilities that enables a population's persistence and defines its impact on the environment. The set of possible niches forms the niche space, a conceptual space delineating ways in which persistence in a system is possible. Here we use manifold learning to map the space of metabolic networks representing thousands of bacterial genera. The results suggest a metabolic niche space comprising a collection of discrete clusters and branching manifolds, which constitute strategies spanning life in different habitats and hosts. We further demonstrate that communities from similar ecosystem types map to characteristic regions of this functional coordinate system, permitting coarse-graining of microbiomes in terms of ecological niches that may be filled.


Assuntos
Bactérias/metabolismo , Bactérias/classificação , Bactérias/genética , Evolução Biológica , Ecossistema , Redes e Vias Metabólicas , Filogenia , Água do Mar/microbiologia , Microbiologia do Solo
11.
Ecotoxicol Environ Saf ; 203: 110984, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32888605

RESUMO

The use of water for drinking and agriculture requires knowledge of its toxicity. In this study, we compared the use of genetically modified bioluminescent (GMB) bacteria whose luminescence increases in the presence of toxicants and Chinese Hamster Ovary (CHO) cells for the characterization of the toxicity of water samples collected from a lake and streams, hydroponic and aquaponic farms, and a wastewater treatment plant. GMB bacteria were used to probe genotoxicity, cytotoxicity and reactive oxygen species-induced effects in the whole water samples. Unlike GMB bacteria, the use of CHO cells requires XAD resin-based pre-concentration of toxic material present in water samples for the subsequent cytotoxicity assay. In addition to the examination of the toxicity of the water from the different sources, the GMB bacteria were also used to test the XAD extracts diluted to the concentrations causing 50% growth inhibition of the CHO cells. The two biomonitoring tools provided different results when they were used to test the above-mentioned diluted XAD extracts. A pre-concentration procedure based on adsorption by XAD resins with subsequent elution was not sufficient to represent the material responsible for the toxicity of the whole water samples toward the GMB bacteria. Therefore, the use of XAD resin extracts may lead to major underestimates of the toxicity of water samples. Although the toxicity findings obtained using the GMB bacteria and CHO cells may not correlate with each another, the GMB bacteria assay did provide a mechanism-specific biomonitoring tool to probe the toxicity of water samples without a need for the pre-concentration step.


Assuntos
Bactérias , Monitoramento Biológico/métodos , Água Potável/análise , Lagos/análise , Rios , Águas Residuárias/análise , Animais , Bactérias/genética , Células CHO , Cricetulus , Hidroponia , Luminescência , Microrganismos Geneticamente Modificados/genética , Eliminação de Resíduos Líquidos
12.
Intern Med ; 59(17): 2089-2094, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32879200

RESUMO

Objective The relationship between gut microbiota and portal hypertension remains unclear. We investigated the characteristics of the gut microbiota in portal hypertension patients with esophago-gastric varices and liver cirrhosis. Methods Thirty-six patients (12 patients with portal hypertension, 12 healthy controls, and 12 non-cirrhosis patients) were enrolled in this university hospital study. Intestinal bacteria and statistical analyses were performed up to the genus level using the terminal restriction fragment length polymorphism method targeting 16S ribosomal RNA genes, with diversified regions characterizing each bacterium. Results Levels of Lactobacillales were significantly higher (p=0.045) and those of Clostridium cluster IV significantly lower (p=0.014) in patients with portal hypertension than in other patients. This Clostridium cluster contains many butanoic acid-producing strains, including Ruminococcace and Faecalibacterium prausnitzii. Clostridium cluster IX levels were also significantly lower (p=0.045) in portal hypertension patients than in other patients. There are many strains of Clostridium that produce propionic acid, and the effects on the host and the function of these bacterial species in the human intestine remain unknown. Regarding the Bifidobacterium genus, which is supposed to decrease as a result of cirrhosis, no significant decrease was observed in this study. Conclusion In the present study, we provided information on the characteristics of the gut microbiota of portal hypertension patients with esophago-gastric varices due to liver cirrhosis. In the future, we aim to develop probiotic treatments following further analyses that include the species level, such as the intestinal flora analysis method and next-generation sequencers.


Assuntos
Bactérias/isolamento & purificação , Microbioma Gastrointestinal , Hipertensão Portal/microbiologia , Cirrose Hepática/complicações , Adulto , Bactérias/genética , Bifidobacterium/isolamento & purificação , Clostridium/isolamento & purificação , Varizes Esofágicas e Gástricas/etiologia , Feminino , Humanos , Hipertensão Portal/etiologia , Intestinos/microbiologia , Masculino , Pessoa de Meia-Idade , Probióticos/uso terapêutico , RNA Bacteriano/análise , RNA Ribossômico 16S/análise , Streptococcus/isolamento & purificação
13.
Nat Commun ; 11(1): 4658, 2020 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-32938931

RESUMO

Dimethylsulfoniopropionate (DMSP) is an important marine osmolyte. Aphotic environments are only recently being considered as potential contributors to global DMSP production. Here, our Mariana Trench study reveals a typical seawater DMSP/dimethylsulfide (DMS) profile, with highest concentrations in the euphotic zone and decreased but consistent levels below. The genetic potential for bacterial DMSP synthesis via the dsyB gene and its transcription is greater in the deep ocean, and is highest in the sediment.s DMSP catabolic potential is present throughout the trench waters, but is less prominent below 8000 m, perhaps indicating a preference to store DMSP in the deep for stress protection. Deep ocean bacterial isolates show enhanced DMSP production under increased hydrostatic pressure. Furthermore, bacterial dsyB mutants are less tolerant of deep ocean pressures than wild-type strains. Thus, we propose a physiological function for DMSP in hydrostatic pressure protection, and that bacteria are key DMSP producers in deep seawater and sediment.


Assuntos
Bactérias/genética , Bactérias/metabolismo , Água do Mar/química , Água do Mar/microbiologia , Compostos de Sulfônio/metabolismo , Bactérias/isolamento & purificação , Clorofila A/análise , Clorofila A/metabolismo , Genes Bacterianos , Sedimentos Geológicos/química , Pressão Hidrostática , Marinobacter/genética , Marinobacter/isolamento & purificação , Marinobacter/metabolismo , Metagenoma , Mutação , Oceanos e Mares , Prochlorococcus/genética , Prochlorococcus/isolamento & purificação , Prochlorococcus/metabolismo , RNA Ribossômico 16S , Sulfetos/análise , Sulfetos/metabolismo , Compostos de Sulfônio/análise , Synechococcus/genética , Synechococcus/isolamento & purificação , Synechococcus/metabolismo
14.
Zhongguo Zhong Yao Za Zhi ; 45(15): 3651-3658, 2020 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-32893554

RESUMO

As an important substitute for agarwood, mountain-agarwood, belonging to the family Oleaceae, comes from the root, stem and thick branch of Syringa pinnatifolia, which has a wide range of application in Inner Mongolia, China. It has good clinical efficacy in the use of cardiovascular diseases. However, the formation speed of mountain-agarwood is extremely slow, and its cultivated seedlings have low resin content. Therefore, how to speed up the formation of mountain-agarwood and increase the resin content is a hot research topic in this field. In this work, 16 S rDNA amplicon sequencing method was used to systematically analyze the bacterial communities of different samples of mountain-agarwood. Our data revealed that the samples of mountain-agarwood had more obvious species diversity than the ones of non-mountain-agarwood, especially the wild mountain-agarwood samples. By analysis of bacterial community composition and species abundance, Sphingomonas, Modestobacter and unidentified Cyanobacteria genus were three dominant bacterial genera in all samples. In addition, there are two identified genera of dominant bacteria, namely Actinoplanes and Microbacterium in both wild and cultivated mountain-agarwood, by bacterial community composition and species richness analysis. Meanwhile, Roseomonas was the dominant bacterial genus in both wild and cultivated non-mountain-agarwood samples. Our work could provides basic data for exploring the mechanism of the mountain-agarwood formation, and help to exploit resource of endophytic bacteria reasonably.


Assuntos
Thymelaeaceae , Bactérias/genética , China , DNA Ribossômico , Resinas Vegetais
15.
Bioresour Technol ; 317: 124037, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32866838

RESUMO

A two-stage anoxic/oxic combined membrane bioreactor (A/O-A/O-MBR) was operated for 81 d to treat landfill leachate under different reflux ratios (R). The best performance was found under R = 150%, where the chemical oxygen demand (COD), ammonium (NH4+-N) and total nitrogen (TN) removal was 85.6%, 99.3%, and 80.7%, respectively. Particularly, the highest pollutant removal was achieved in the second-stage A/O, where the COD and TN removal capacity was 78.88 and 11.74 g/d, respectively. Meantime, DOM removal was 83.9%, where the removal of aromatic protein substances I and II, fulvic acids-like compounds, soluble microbial products and humic acids-like compounds was 93.4%, 86.4%, 72.0%, 86.6% and 59.4%, respectively. The gene functions of microbial community in the process showed that amoA, hao, nirK and nosZ, etc. were the core genes for nitrification and denitrification. The carbon source for denitrification might come from the conversion of refractory organic matters in landfill leachate.


Assuntos
Nitrogênio , Poluentes Químicos da Água , Bactérias/genética , Reatores Biológicos , Desnitrificação , Nitrificação
16.
PLoS One ; 15(8): e0237748, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32866195

RESUMO

Soil microbiota are considered a source of undiscovered bioactive compounds, yet cultivation of most bacteria within a sample remains generally unsuccessful. Two main reasons behind the unculturability of bacteria are the presence of cells in a viable but not culturable state (such as dormant cells) and the failure to provide the necessary growth requirements in vitro (leading to the classification of some bacterial taxa as yet-to-be-cultured). The present work focuses on the development of a single procedure that helps distinguish between both phenomena of unculturability based on viability staining coupled with flow cytometry and fluorescence-activated cell sorting. In the selected soil sample, the success rate of cultured bacteria was doubled by selecting viable and metabolically active bacteria. It was determined that most of the uncultured fraction was not dormant or dead but likely required different growth conditions. It was also determined that the staining process introduced changes in the taxonomic composition of the outgrown bacterial biomass, which should be considered for further developments. This research shows the potential of flow cytometry and fluorescence-activated cell sorting applied to soil samples to improve the success rate of bacterial cultivation by estimating the proportion of dormant and yet-to-be-cultured bacteria and by directly excluding dormant cells from being inoculated into growth media.


Assuntos
Bactérias/crescimento & desenvolvimento , Técnicas Microbiológicas/métodos , Microbiota/fisiologia , Microbiologia do Solo , Bactérias/química , Bactérias/genética , Biomassa , Separação Celular/métodos , Meios de Cultura , DNA Bacteriano/isolamento & purificação , Estudos de Viabilidade , Citometria de Fluxo/métodos , Corantes Fluorescentes/química , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Coloração e Rotulagem/métodos
17.
Nat Commun ; 11(1): 4365, 2020 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-32868761

RESUMO

Current approaches explore bacterial genes that change transcriptionally upon stress exposure as diagnostics to predict antibiotic sensitivity. However, transcriptional changes are often specific to a species or antibiotic, limiting implementation to known settings only. While a generalizable approach, predicting bacterial fitness independent of strain, species or type of stress, would eliminate such limitations, it is unclear whether a stress-response can be universally captured. By generating a multi-stress and species RNA-Seq and experimental evolution dataset, we highlight the strengths and limitations of existing gene-panel based methods. Subsequently, we build a generalizable method around the observation that global transcriptional disorder seems to be a common, low-fitness, stress response. We quantify this disorder using entropy, which is a specific measure of randomness, and find that in low fitness cases increasing entropy and transcriptional disorder results from a loss of regulatory gene-dependencies. Using entropy as a single feature, we show that fitness and quantitative antibiotic sensitivity predictions can be made that generalize well beyond training data. Furthermore, we validate entropy-based predictions in 7 species under antibiotic and non-antibiotic conditions. By demonstrating the feasibility of universal predictions of bacterial fitness, this work establishes the fundamentals for potentially new approaches in infectious disease diagnostics.


Assuntos
Bactérias/genética , Evolução Molecular Direcionada , Farmacorresistência Bacteriana/genética , Estresse Fisiológico , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/metabolismo , Fenômenos Fisiológicos Bacterianos , Doenças Transmissíveis/diagnóstico , Entropia , Regulação Bacteriana da Expressão Gênica , Genes Bacterianos , Genoma Bacteriano , Análise de Sequência de RNA , Streptococcus pneumoniae/efeitos dos fármacos , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/metabolismo , Transcriptoma
19.
Nat Commun ; 11(1): 4897, 2020 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-32994415

RESUMO

Soil microbial respiration is an important source of uncertainty in projecting future climate and carbon (C) cycle feedbacks. However, its feedbacks to climate warming and underlying microbial mechanisms are still poorly understood. Here we show that the temperature sensitivity of soil microbial respiration (Q10) in a temperate grassland ecosystem persistently decreases by 12.0 ± 3.7% across 7 years of warming. Also, the shifts of microbial communities play critical roles in regulating thermal adaptation of soil respiration. Incorporating microbial functional gene abundance data into a microbially-enabled ecosystem model significantly improves the modeling performance of soil microbial respiration by 5-19%, and reduces model parametric uncertainty by 55-71%. In addition, modeling analyses show that the microbial thermal adaptation can lead to considerably less heterotrophic respiration (11.6 ± 7.5%), and hence less soil C loss. If such microbially mediated dampening effects occur generally across different spatial and temporal scales, the potential positive feedback of soil microbial respiration in response to climate warming may be less than previously predicted.


Assuntos
Carbono/análise , Metagenoma/genética , Microbiota/fisiologia , Microbiologia do Solo , Solo/química , Aclimatação/genética , Archaea/genética , Archaea/isolamento & purificação , Archaea/metabolismo , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Carbono/metabolismo , Ciclo do Carbono , Celulose/metabolismo , DNA Ambiental/genética , DNA Ambiental/isolamento & purificação , Fungos/genética , Fungos/isolamento & purificação , Fungos/metabolismo , Aquecimento Global , Pradaria , Temperatura Alta/efeitos adversos , Metagenômica , Modelos Genéticos , Raízes de Plantas/química , Poaceae/química
20.
Chemosphere ; 254: 126891, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957291

RESUMO

Gut microbiota executes many beneficial functions. In this study, the relationship between gut microbiota and ovarian development in the swimming crab P. trituberculatus was explored for the first time. A total of 28 phyla and 422 genera were identified across all samples. However, 105 differential operational taxonomic units, and four differential phyla (Gemmatimonadetes, Actinobacteria, Firmicutes, Marinimicrobia_(SAR406_clade)) were identified. At the genus level, 42 differential genera were identified and 144 bacterial indicators were identified. A key finding was that the relative abundance of 139 indicator bacteria detected in the anisomycin-2 mg/kg group (AK group) was higher than that of blank group (BK group), control group (CK group), SP600125-15 mg/kg group (SK group). In addition, the relative abundance of three indicator bacteria (OTU_236, OTU_1395, OTU_552) detected in the SK group was higher than that of the BK, CK and AK groups. It was also found that the relative abundance of 20 differential genera (Methyloversatilis, Coprococcus_1, Erysipelotrichaceae_UCG_003, Rikenella, Corynebacterium, Ruminiclostridium, Fusicatenibacter, [Eubacterium]_ruminantium_group, Rikenellaceae_RC9_gut_group, Bifidobacterium, Lachnospiraceae_NK4A136_group, Ruminococcaceae_UCG_014, Christensenellaceae_R_7_group, uncultured_Bacteroidales_bacterium, Coprococcus_2, Desulfovibrio, Aggregatibacter, Ambiguous_taxa, Alloprevotella and Ruminococcaceae_NK4A214_group) in the SK, BK, CK, and AK group samples were increasing. These differential genera may reveal the relationship between gut microbial communities and ovarian development in P. trituberculatus after injection with the JNK pathway inhibitor SP600125 or the activator anisomycin. In summary, this study provides a new understanding into the relationship between gut microbiota and ovarian development in response to stimulation with inhibitor or activator.


Assuntos
Braquiúros/fisiologia , Microbioma Gastrointestinal/fisiologia , Animais , Bactérias/genética , Feminino , Microbioma Gastrointestinal/genética , Microbiota , RNA Ribossômico 16S/genética , Natação
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