Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 338
Filtrar
1.
Antonie Van Leeuwenhoek ; 114(12): 2101-2111, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34599477

RESUMO

A polyphasic taxonomic approach was used to characterize a Gram-stain-negative bacterium, designated strain CC-CFT501T, harboring xenobiotic- and allelochemical-metabolizing genes, isolated from a long-term ecological research field in Taiwan. Cells of strain CC-CFT501T were catalase- and oxidase-positive, non-motile and short rods. Optimal growth occurred at 30 °C, pH 8 and 1% NaCl. Strain CC-CFT501T was found to share high 16S rRNA gene sequence similarity with the members of genera Quisquiliibacterium (94.3%, n = 1), Pandoraea (93.4-94.0%, n = 23) and Paraburkholderia (93.3-94.0%, n = 9), affiliated to the family Burkholderiaceae. Strain CC-CFT501T shared 76.4% orthologous average nucleotide identity (OrthoANI) and 20.9% digital DNA-DNA hybridization (dDDH) values with Quisquiliibacterium transsilvanicum DSM 29781T. Draft genome sequence (3.83 Mb) of strain CC-CFT501T revealed several genes encoding the proteins involved in biphenyl and phenolic acid metabolism. Fatty acid profile contained C16:0, C18:0, C10:0 3-OH, C16:1 ω7c/C16:1 ω6c and C18:1 ω7c/C18:1 ω6c in predominant amounts. The polar lipid profile consisted of phosphatidylethanolamine, thirteen unidentified amino lipids, two unidentified phospholipids and two unidentified glycolipids. The major polyamine was spermidine and ubiquinone Q-8 was the sole respiratory quinone. The DNA G + C content was 70.0 mol%. Based on its distinct phylogenetic, phenotypic and chemotaxonomic traits together with results of comparative 16S rRNA gene sequence, ANI and dDDH analyses, strain CC-CFT501T is considered to represent a novel genus and species of the family Burkholderiaceae, for which the name Zeimonas arvi gen. nov., sp. nov. is proposed. The type strain of the type species is CC-CFT501T (= BCRC 81218T = JCM 33506T).


Assuntos
Burkholderiaceae , Técnicas de Tipagem Bacteriana , Compostos de Bifenilo , DNA Bacteriano/genética , Ácidos Graxos , Hidroxibenzoatos , Fosfolipídeos , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
2.
BMC Oral Health ; 21(1): 490, 2021 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-34602059

RESUMO

BACKGROUND: Many factors can contribute to the exact makeup of the salivary microbiome. Differences in the oral microbiome occur with old age, which may be due to oral conditions and diseases associated with old age, such as edentulism, as well as other unknown causes. METHODS: The salivary microbiome was sampled in patients from a large urban clinic. For all subjects age, gender, periodontal status, caries status, presence of edentulism, medications, and tobacco usage were recorded. Multifactor analysis was used to study variation in salivary microbiome profiles linked to these factors. RESULTS: In the population sampled, there were significantly higher numbers of edentulous subjects, and increased levels of polypharmacy found with aging. Large differences in alpha diversity and beta diversity of the salivary microbiome in the old age group were largely linked to edentulism. However, multivariable analysis revealed, even after adjusting for differences in edentulism, polypharmacy, tobacco usage, periodontal disease, caries level, and gender, that old age itself was associated with lower levels of taxa Porphyromonas endodontalis, Alloprevotella tannerae, Filifactor alocis, Treponema, Lautropia Mirabilis and Pseudopropionibacterium sp._HMT_194. Surprisingly, of these taxa, most were ones known to reside on or near tooth surfaces. CONCLUSIONS: Another factor or factors beyond edentulism, polypharmacy and periodontal disease play a role in the differences seen in oral microbiome with old age. The nature of this factor(s) is not known.


Assuntos
Microbiota , Saliva , Fatores Etários , Idoso , Bacteroidetes , Burkholderiaceae , Clostridiales , Humanos , RNA Ribossômico 16S , Saliva/microbiologia
3.
Int J Syst Evol Microbiol ; 71(10)2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34694983

RESUMO

Two white colony-forming, Gram-stain-negative, non-sporulating and motile bacteria, designated G-4-1-8T and RP-4-7T, were isolated from forest soil and Arctic soil, respectively. Both strains showed antimicrobial activity against Gram-negative pathogens (Pseudomonas aeruginosa and Escherichia coli) and could grow at a pH range of pH 4.0-11.0 (optimum, pH 7.0-9.0). Phylogenetic analyses based on their 16S rRNA gene sequences indicated that strains G-4-1-8T and RP-4-7T formed a lineage within the family Burkholderiaceae and were clustered as members of the genus Paraburkholderia. Strain G-4-1-8T showed the highest 16S rRNA sequence similarity to Paraburkholderia monticola JC2948T (98.1 %), while strain RP-4-7T showed the highest similarity to Paraburkholderia metrosideri DNBP6-1T (98.8 %). The only respiratory quinone in both strains was ubiquinone Q-8. Their principal cellular fatty acids were C16 : 0, cyclo-C17 : 0, summed feature 3 (iso-C15 :0 2-OH and/or C16 :1 ω7c) and summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c). Their major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and an unidentified aminophospholipid. The DNA G+C content of strains G-4-1-8T and RP-4-7T were 63.7 and 61.3 mol%, respectively, while their genome lengths were 7.44 and 9.67 Mb, respectively. The genomes of both strains showed at least 12 putative biosynthetic gene clusters. The average nucleotide identity and in silico DNA-DNA hybridization relatedness values between both strains and most closely related Paraburkholderia species were below the species threshold values. Based on a polyphasic study, these isolated strains represent novel species belonging to the genus Paraburkholderia, for which the names Paraburkholderia antibiotica sp. nov. (G-4-1-8T= KACC 21617T=NBRC 114603T) and Paraburkholderia polaris sp. nov. (RP-4-7T=KACC 21621T=NBRC 114605T) are proposed.


Assuntos
Antibacterianos , Burkholderiaceae , Técnicas de Tipagem Bacteriana , Composição de Bases , Burkholderiaceae/genética , DNA Bacteriano/genética , Ácidos Graxos/química , Fosfolipídeos , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Microbiologia do Solo
4.
Artigo em Inglês | MEDLINE | ID: mdl-34542391

RESUMO

A novel bacterium, designated strain Msb3T, was recently isolated from leaves of the yam family plant Dioscorea bulbifera (Dioscoreaceae). Phylogenetic analysis based on the 16S rRNA gene sequence indicated that this strain belonged to the genus Paraburkholderia with Paraburkholderia xenovorans as nearest validly named neighbour taxon (99.3 % sequence similarity towards the P. xenovorans type strain). Earlier genome sequence analysis revealed a genome of 8.35 Mb in size with a G+C content of 62.5 mol%, which was distributed over two chromosomes and three plasmids. Here, we confirm that strain Msb3T represents a novel Paraburkholderia species. In silico DNA-DNA hybridization and average nucleotide identity (OrthoANIu) analyses towards P. xenovorans LB400T yielded 58.4 % dDDH and 94.5 % orthoANIu. Phenotypic and metabolic characterization revealed growth at 15 °C on tryptic soy agar, growth in the presence of 1 % NaCl and the lack of assimilation of phenylacetic acid as distinctive features. Together, these data demonstrate that strain Msb3T represents a novel species of the genus Paraburkholderia, for which we propose the name Paraburkholderia dioscoreae sp. nov. The type strain is Msb3T (=LMG 31881T, DSM 111632T, CECT 30342T).


Assuntos
Florestas , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , Burkholderiaceae , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Fosfolipídeos , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona
5.
Sci Total Environ ; 800: 149493, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34426366

RESUMO

The development and productivity of plants are governed by their genetic background, nutrient input, and the microbial communities they host, i.e. the holobiont. Accordingly, engineering beneficial root microbiomes has emerged as a novel and sustainable approach to crop production with reduced nutrient input. Here, we tested the effects of six bacterial strains isolated from sugarcane stalks on sugarcane growth and physiology as well as the dynamics of prokaryote community assembly in the rhizosphere and root endosphere under two N fertilization regimes. All six strains, Paraburkholderia caribensis IAC/BECa 88, Kosakonia oryzae IAC/BECa 90, Kosakonia radicincitans IAC/BECa 95, Paraburkholderia tropica IAC/BECa 135, Pseudomonas fluorescens IAC/BECa 141 and Herbaspirillum frisingense IAC/BECa 152, increased in shoot and root dry mass, and influenced the concentration and accumulation of important macro- and micronutrients. However, N input reduced the impact of inoculation by shifting the sugarcane microbiome (rhizosphere and root endosphere) and weakening the co-dependence between soil microbes and sugarcane biomass and nutrients. The results show that these beneficial microbes improved plant nutrient uptake conditioned to a reduced N nutrient input. Therefore, reduced fertilization is not only desirable consequence of bacterial inoculation but essential for higher impact of these beneficial bacteria on the sugarcane microbiome.


Assuntos
Saccharum , Bactérias , Burkholderiaceae , Enterobacteriaceae , Herbaspirillum , Nitrogênio , Raízes de Plantas , Rizosfera , Microbiologia do Solo
6.
Nat Commun ; 12(1): 4347, 2021 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-34301933

RESUMO

Heterologous expression of biosynthetic gene clusters (BGCs) avails yield improvements and mining of natural products, but it is limited by lacking of more efficient Gram-negative chassis. The proteobacterium Schlegelella brevitalea DSM 7029 exhibits potential for heterologous BGC expression, but its cells undergo early autolysis, hindering further applications. Herein, we rationally construct DC and DT series genome-reduced S. brevitalea mutants by sequential deletions of endogenous BGCs and the nonessential genomic regions, respectively. The DC5 to DC7 mutants affect growth, while the DT series mutants show improved growth characteristics with alleviated cell autolysis. The yield improvements of six proteobacterial natural products and successful identification of chitinimides from Chitinimonas koreensis via heterologous expression in DT mutants demonstrate their superiority to wild-type DSM 7029 and two commonly used Gram-negative chassis Escherichia coli and Pseudomonas putida. Our study expands the panel of Gram-negative chassis and facilitates the discovery of natural products by heterologous expression.


Assuntos
Produtos Biológicos/metabolismo , Burkholderiales/genética , Genoma Bacteriano/genética , Família Multigênica/genética , Proteobactérias/genética , Burkholderiaceae/genética , Burkholderiaceae/metabolismo , Burkholderiales/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Regulação Bacteriana da Expressão Gênica , Engenharia Genética/métodos , Mutação , Policetídeos/metabolismo , Proteobactérias/metabolismo , Pseudomonas putida/genética , Pseudomonas putida/metabolismo
7.
Bioresour Technol ; 337: 125472, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34320752

RESUMO

This is the first review presenting and discussing Burkholderia sacchari as a bacterial chassis. B. sacchari is a distinguished polyhydroxyalkanoates producer strain, with low biological risk, reaching high biopolymer yields from sucrose (0.29 g/g), and xylose (0.38 g/g). It has great potential for integration into a biorefinery using residues from biomass, achieving 146 g/L cell dry weight containing 72% polyhydroxyalkanoates. Xylitol (about 70 g/L) and xylonic acid [about 390 g/L, productivity 7.7 g/(L.h)] are produced by the wild-type B. sacchari. Recombinants were constructed to allow the production and monomer composition control of diverse tailor-made polyhydroxyalkanoates, and some applications have been tested. 3-hydroxyvalerate and 3-hydroxyhexanoate yields from substrate reached 80% and 50%, respectively. The genome-scale reconstruction of its metabolic network, associated with the improvement of tools for genetic modification, and metabolic fluxes understanding by future research, will consolidate its potential as a bioproduction chassis.


Assuntos
Burkholderia , Burkholderiaceae , Poli-Hidroxialcanoatos , Biopolímeros , Burkholderia/genética
8.
J Hazard Mater ; 417: 126151, 2021 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-34229401

RESUMO

Azoles are an emerging class of contaminants with a growing ubiquitous presence in the environment. This study investigates the aerobic microbial degradation of four azoles, pyrazole (PA), 1,2,4-triazole (TA), benzotriazole (BTA) and 5-methylbenzotriazole (5-MBTA), with return activated sludge and microbial enrichment cultures. Slow degradation of PA was observed in the presence of glucose and NH4+ with a peak degradation rate of 0.5 mg d-1 gVSS-1. TA was found to be highly persistent, with no significant degradation observed in 6-8 months under any incubation condition. In contrast, the benzotriazoles were readily degraded at faster rates in all incubation conditions. The degradation rates observed for BTA and 5-MBTA, when provided as the sole substrates, were 8.1 and 16.5 mg d-1 gVSS-1, respectively. Two enrichment cultures, one degrading BTA and the other degrading 5-MBTA, were developed from the activated sludge. Mass balance studies revealed complete mineralization of 5-MBTA and partial breakdown of BTA by the enrichment cultures. Nocardioides sp. and Pandoraea pnomenusa were the most abundant bacteria in the BTA and 5-MBTA degrading enrichment cultures, respectively. The research shows large differences in the biodegradability of various azoles, ranging from complete mineralization of 5-MBTA to complete persistence for TA.


Assuntos
Burkholderiaceae , Esgotos , Azóis , Biodegradação Ambiental
9.
Artigo em Inglês | MEDLINE | ID: mdl-34287117

RESUMO

An intracellular bacterium, strain IAST, was observed to infect several species of the plant-parasitic nematode genus Xiphinema (Xiphinema astaregiense, Xiphinema incertum, Xiphinema madeirense, Xiphinema pachtaicum, Xiphinema parapachydermum and Xiphinema vallense). The bacterium could not be recovered on axenic medium. The 16S rRNA gene sequence of IAST was found to be new, being related to the family Burkholderiaceae, class Betaproteobacteria. Fungal endosymbionts Mycoavidus cysteinexigens B1-EBT (92.9 % sequence identity) and 'Candidatus Glomeribacter gigasporarum' BEG34 (89.8 % identity) are the closest taxa and form a separate phylogenetic clade inside Burkholderiaceae. Other genes (atpD, lepA and recA) also separated this species from its closest relatives using a multilocus sequence analysis approach. These genes were obtained using a partial genome of this bacterium. The localization of the bacterium (via light and fluorescence in situ hybridization microscopy) is in the X. pachtaicum females clustered around the developing oocytes, primarily found embedded inside the epithelial wall cells of the ovaries, from where they are dispersed in the intestine. Transmission electron microscopy (TEM) observations supported the presence of bacteria inside the nematode body, where they occupy ovaries and occur inside the intestinal epithelium. Ultrastructural analysis of the bacterium showed cells that appear as mostly irregular, slightly curved rods with rounded ends, 0.8-1.2 µm wide and 2.5-6.0 µm long, possessing a typical Gram-negative cell wall. The peptidoglycan layer is, however, evident only occasionally and not detectable by TEM in most cells. Another irregularly occurring shell surrounding the endosymbiont cells or the cell clusters was also revealed, probably originating from the host cell membrane. Flagella or spore-like cells do not occur and the nucleoid is diffusely distributed throughout the cell. This endosymbiont is transmitted vertically through nematode generations. These results support the proposal of IAST as a new species, although its obligate intracellular and obligate endosymbiont nature prevented isolation of a definitive type strain. Strain IAST is therefore proposed as representing 'Candidatus Xiphinematincola pachtaicus' gen. nov., sp. nov.


Assuntos
Burkholderiaceae/classificação , Nematoides/microbiologia , Filogenia , Simbiose , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , Burkholderiaceae/isolamento & purificação , Citrus/parasitologia , DNA Bacteriano/genética , Ácidos Graxos/química , Feminino , Genes Bacterianos , Hibridização in Situ Fluorescente , RNA Ribossômico 16S/genética , Rizosfera , Análise de Sequência de DNA , Espanha
10.
Int J Mol Sci ; 22(13)2021 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-34209778

RESUMO

We performed a taxonomic and comparative genomics analysis of 67 novel Paraburkholderia isolates from forest soil. Phylogenetic analysis of the recA gene revealed that these isolates formed a coherent lineage within the genus Paraburkholderia that also included Paraburkholderiaaspalathi, Paraburkholderiamadseniana, Paraburkholderiasediminicola, Paraburkholderiacaffeinilytica, Paraburkholderiasolitsugae and Paraburkholderiaelongata and four unidentified soil isolates from earlier studies. A phylogenomic analysis, along with orthoANIu and digital DNA-DNA hybridization calculations revealed that they represented four different species including three novel species and P. aspalathi. Functional genome annotation of the strains revealed several pathways for aromatic compound degradation and the presence of mono- and dioxygenases involved in the degradation of the lignin-derived compounds ferulic acid and p-coumaric acid. This co-occurrence of multiple Paraburkholderia strains and species with the capacity to degrade aromatic compounds in pristine forest soil is likely caused by the abundant presence of aromatic compounds in decomposing plant litter and may highlight a diversity in micro-habitats or be indicative of synergistic relationships. We propose to classify the isolates representing novel species as Paraburkholderia domus with LMG 31832T (=CECT 30334) as the type strain, Paraburkholderia nemoris with LMG 31836T (=CECT 30335) as the type strain and Paraburkholderia haematera with LMG 31837T (=CECT 30336) as the type strain and provide an emended description of Paraburkholderia sediminicola Lim et al. 2008.


Assuntos
Burkholderiaceae/classificação , Burkholderiaceae/genética , Hidrocarbonetos Aromáticos/metabolismo , Técnicas de Tipagem Bacteriana , Burkholderiaceae/isolamento & purificação , Burkholderiaceae/metabolismo , Ácidos Cumáricos/metabolismo , Ácidos Cumáricos/farmacocinética , DNA Bacteriano/análise , DNA Bacteriano/genética , Recuperação e Remediação Ambiental/métodos , Florestas , Genoma Bacteriano , Hidrocarbonetos Aromáticos/farmacocinética , Filogenia , RNA Ribossômico 16S/genética , Recombinases Rec A/análise , Recombinases Rec A/genética , Análise de Sequência de DNA , Microbiologia do Solo
11.
Artigo em Inglês | MEDLINE | ID: mdl-34165423

RESUMO

Burkholderia novacaledonica is a Betaproteobacterial species isolated from ultramafic soils in New Caledonia. The characterization and classification of this species into the Burkholderia genus was done simultaneously with the proposal of the new genus Caballeronia, initially composed of closely related Burkholderia glathei-like species. Thereafter, some reports based on the use of phylogenetic marker genes suggested that B. novacaledonica forms part of Caballeronia genus. Lacking a formal validation, and with the availability of its genome sequence, a genome-based phylogeny of B. novacaledonica was obtained to unravel its taxonomic position in Burkholderia sensu lato. A partial gyrB gene phylogeny, extended multilocus sequence typing on homologous protein sequences, and genomic distance-based phylogeny, all support the placement of this species in the Caballeronia genus. Therefore, the reclassification of B. novacaledonica to Caballeronia novacaledonica comb. nov. is proposed.


Assuntos
Burkholderia/classificação , Burkholderia/genética , Filogenia , Técnicas de Tipagem Bacteriana , Sequência de Bases , Burkholderiaceae/classificação , Burkholderiaceae/genética , DNA Bacteriano/genética , Ácidos Graxos/análise , Ácidos Graxos/química , Tipagem de Sequências Multilocus , Nova Caledônia , Análise de Sequência de DNA , Microbiologia do Solo
12.
J Environ Radioact ; 237: 106682, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34148005

RESUMO

The supply of K, being the chemical analog of Cs, affects the phytotransfer of radiocesium such as 137Cs from contaminated soils and its accumulation in plant tissues. Since K and Cs have high affinity to the same clay particle surfaces, the presence of potassium-solubilizing bacteria (KSB) could increase the availability of not only K+ in the rhizosphere but also of radiocesium. In this study, we obtained five KSB isolates with the highest solubilization capacities from soybean rhizosphere on modified Aleksandrov medium containing sericite as K source. Based on biochemical and 16S rRNA gene sequence analysis, we identified the bacteria as Bacillus aryabhattai MG774424, Pseudomonas umsongensis MG774425, P. frederiksbergensis MG774426, Burkholderia sabiae MG774427, and P. mandelii MG774428. We evaluated the KSB isolates based on plant growth promotion and 137Cs accumulation in komatsuna (Brassica rapa L. var. Perviridis) grown in three soils collected from Miyanoiri, Takanishi, and Ota contaminated by 137Cs from the Fukushima accident. Inoculation with KSB showed beneficial effects on plant growth and increased the overall plant biomass production (~40%). On the average, KSB inoculation resulted in the removal of 0.07 ± 0.04% of 137Cs from the soil, more than twice the control. But similar to the effect of KSB inoculation on komatsuna biomass production, different KSBs performed variably and exhibited site-specific responses independent of their K-solubilizing capacities, with higher 137Cs phyto-transfer in roots than in shoots. In terms of root transfer factor (TF), values were highest in komatsuna plants grown in Miyanoiri and Ota soils inoculated with P. frederiksbergensis and Burkholderia sabiae, while they were highest in Takanishi soils inoculated with Bacillus aryabhattai and P. umsongensis. These TF values were also much higher than previously reported values for komatsuna grown in 137Cs-contaminated Fukushima soils inoculated with other rhizobacteria. Thus, KSB inoculation significantly enhance not only the growth of komatsuna but 137Cs uptake.


Assuntos
Brassica rapa , Monitoramento de Radiação , Poluentes Radioativos do Solo , Bacillus , Bactérias/genética , Biodegradação Ambiental , Burkholderiaceae , Radioisótopos de Césio/análise , Potássio , Pseudomonas , RNA Ribossômico 16S , Solo , Poluentes Radioativos do Solo/análise
13.
Environ Res ; 201: 111594, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34186080

RESUMO

This research was aimed to evaluate the phytochemical profile, bactericidal activity of Hygrophila spinosa against multidrug resistant Pandoraea sputorum and assess their antioxidant competence against various radicals and studied their hepatoprotective and nephroprotective activity on HepG2 and HEK 293 cell line. The results showed that the methanol extract has various phytochemical components with reasonable quantity. Fortunately, the multidrug-resistant P. sputorum was sensitive (22.8 ± 0.2 mm of the zone of inhibition) at 15 mg mL-1 concentration of methanol extract. The higher concentration of phenolic and other phytochemical components, showed significant antioxidant activity against ferric, DPPH, hydroxyl, and ABTS radicals, with IC50 values of 71.09, 64.333, 91.157, and 104.931 g mL-1, respectively. Surprisingly, the methanol extract possesses hepato and nephroprotective activity against CCl4 and cisplatin-induced cytotoxicity on HepG2 and HEK 293 cell lines, respectively. It maintains the cell viability as up to 90.48% and 90.35% of HepG2 and EK 293 cell line at the concentration of 20 µg mL-1. The FTIR analysis states that the methanol extract possesses a significant functional group responsible for these multi-potential activities. These results suggest that, the methanol extract of H. spinosa might contain the most significant bioactive components with outstanding medicinal properties.


Assuntos
Acanthaceae , Antibacterianos , Burkholderiaceae/efeitos dos fármacos , Extratos Vegetais , Substâncias Protetoras/farmacologia , Acanthaceae/química , Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla , Células HEK293 , Células Hep G2 , Humanos , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Metanol , Extratos Vegetais/farmacologia
14.
Mol Ecol Resour ; 21(7): 2471-2485, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34101998

RESUMO

Current knowledge on environmental distribution and taxon richness of free-living bacteria is mainly based on cultivation-independent investigations employing 16S rRNA gene sequencing methods. Yet, 16S rRNA genes are evolutionarily rather conserved, resulting in limited taxonomic and ecological resolutions provided by this marker. The faster evolving protein-encoding gene priB was used to reveal ecological patterns hidden within a single operational taxonomic unit (OTU) defined by >99% 16S rRNA sequence similarity. The studied subcluster PnecC of the genus Polynucleobacter represents a ubiquitous group of abundant freshwater bacteria with cosmopolitan distribution, which is very frequently detected by diversity surveys of freshwater systems. Based on genome taxonomy and a large set of genome sequences, a sequence similarity threshold for delineation of species-like taxa could be established. In total, 600 species-like taxa were detected in 99 freshwater habitats scattered across three regions representing a latitudinal range of 3,400 km (42°N to 71°N) and a pH gradient of 4.2 to 8.6. In addition to the unexpectedly high richness, the increased taxonomic resolution revealed structuring of Polynucleobacter communities by a couple of macroecological trends, which was previously only demonstrated for phylogenetically much broader groups of bacteria. An unexpected pattern was the almost complete compositional separation of Polynucleobacter communities of Ca2+ -rich and Ca2+ -poor habitats. This compositional pattern strongly resembled the vicariance of plant species on silicate and limestone soils. The new cultivation-independent approach presented opened a window to an incredible, previously unseen diversity, and enables investigations aiming on deeper understanding of how environmental conditions shape bacterial communities and drive evolution of free-living bacteria.


Assuntos
Burkholderiaceae , Bactérias/genética , Burkholderiaceae/genética , DNA Bacteriano/genética , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
15.
Syst Appl Microbiol ; 44(3): 126208, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33992956

RESUMO

Mimosa tenuiflora (Willd.) Poir. is widespread in southern and central American drylands, but little information is available concerning its associated rhizobia. Therefore, this study aimed to characterize M. tenuiflora rhizobia from soils of the tropical dry forests (Caatinga) in Pernambuco State, Brazil, at the molecular and symbiotic levels. Soil samples of pristine Caatinga areas in four municipalities were used to grow M. tenuiflora. First, the bacteria from root nodules were subjected to nodC/nifH gene amplification, and the bacteria positive for both genes had the 16S rRNA gene sequenced. Then, ten strains were evaluated using recA, gyrB, and nodC gene sequences, and seven of them had their symbiotic efficiency assessed. Thirty-two strains were obtained and 22 of them were nodC/nifH positive. Twenty strains clustered within Paraburkholderia and two within Rhizobium by 16S rRNA gene sequencing. The beta-rhizobia were similar to P. phenoliruptrix (12) and P. diazotrophica (8). Both alpha-rhizobia were closely related to R. miluonense. The recA + gyrB phylogenetic analysis clustered four and five strains within the P. phenoliruptrix and P. diazotrophica branches, respectively, but they were somewhat divergent to the 16S rRNA phylogeny. For Rhizobium sp. ESA 637, the recA + gyrB phylogeny clustered the strain with R. jaguaris. The nodC phylogeny indicated that ESA 626, ESA 629, and ESA 630 probably represented a new symbiovar branch. The inoculation assay showed high symbiotic efficiency for all tested strains. The results indicated high genetic diversity and efficiency of M. tenuiflora rhizobia in Brazilian drylands and included P. phenoliruptrix-like bacteria in the list of efficient beta-rhizobia in the Caatinga biome.


Assuntos
Burkholderiaceae/classificação , Florestas , Mimosa , Filogenia , Microbiologia do Solo , Brasil , Burkholderiaceae/isolamento & purificação , DNA Bacteriano/genética , Mimosa/microbiologia , RNA Ribossômico 16S/genética , Solo , Simbiose
16.
J Biosci Bioeng ; 132(1): 18-24, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33846091

RESUMO

2,5-Furandicarboxylic acid (FDCA) is a valuable compound that can be synthesized from biomass-derived hydroxymethylfurfural (HMF), and holds great potential as a promising replacement for petroleum-based terephthalic acid in the production of polyamides, polyesters, and polyurethanes used universally. However, an economical large-scale production strategy for HMF from lignocellulosic biomass is yet to be established. This study aimed to design a synthetic pathway that can yield FDCA from furfural, whose industrial production from lignocellulosic biomass has already been established. This artificial pathway consists of an oxidase and a prenylated flavin mononucleotide (prFMN)-dependent reversible decarboxylase, catalyzing furfural oxidation and carboxylation of 2-furoic acid, respectively. The prFMN-dependent reversible decarboxylase was identified in an isolated strain, Paraburkholderia fungorum KK1, whereas an HMF oxidase from Methylovorus sp. MP688 exhibited furfural oxidation activity and was used as a furfural oxidase. Using Escherichia coli cells coexpressing these proteins, as well as a flavin prenyltransferase, FDCA could be produced from furfural via 2-furoic acid in one pot.


Assuntos
Biocatálise , Ácidos Dicarboxílicos/metabolismo , Furaldeído/metabolismo , Furanos/metabolismo , Biomassa , Burkholderiaceae/enzimologia , Burkholderiaceae/metabolismo , Carboxiliases/metabolismo , Oxirredução , Oxirredutases/metabolismo
17.
Appl Environ Microbiol ; 87(12): e0047121, 2021 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-33837018

RESUMO

Acyl coenzyme A (CoA) binding protein (ACBP), also called diazepam-binding inhibitor (DBI), is a phylogenetically conserved protein that is expressed by all eukaryotic species as well as by some bacteria. Since elevated ACBP/DBI levels play a major role in the inhibition of autophagy, increase in appetite, and enhanced lipid storage that accompany obesity, we wondered whether ACBP/DBI produced by the human microbiome might affect host weight. We found that the genomes of bacterial commensals rarely contain ACBP/DBI homologues, which are rather encoded by genomes of some pathogenic or environmental taxa that were not prevalent in human feces. Exhaustive bioinformatic analyses of 1,899 gut samples from healthy individuals refuted the hypothesis that bacterial ACBP/DBI might affect the body mass index (BMI) in a physiological context. Thus, the physiological regulation of BMI is unlikely to be affected by microbial ACBP/DBI-like proteins. However, at the speculative level, it remains possible that ACBP/DBI produced by potential pathogenic bacteria might enhance their virulence by inhibiting autophagy and hence subverting innate immune responses. IMPORTANCE Acyl coenzyme A (CoA) binding protein (ACBP) can be encoded by several organisms across the domains of life, including microbes, and has shown to play major roles in human metabolic processes. However, little is known about its presence in the human gut microbiome and whether its microbial counterpart could also play a role in human metabolism. In the present study, we found that microbial ACBP/DBI sequences were rarely present in the gut microbiome across multiple metagenomic data sets. Microbes that carried ACBP/DBI in the human gut microbiome included Saccharomyces cerevisiae, Lautropia mirabilis, and Comamonas kerstersii, but these microorganisms were not associated with body mass index, further indicating an unconvincing role for microbial ACBP/DBI in human metabolism.


Assuntos
Proteínas de Bactérias/genética , Inibidor da Ligação a Diazepam/genética , Microbioma Gastrointestinal/genética , Obesidade/microbiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Índice de Massa Corporal , Burkholderiaceae/genética , Comamonas/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Saccharomyces cerevisiae/genética , Adulto Jovem
18.
Cells ; 10(4)2021 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-33924023

RESUMO

Homocitrate is an essential component of the iron-molybdenum cofactor of nitrogenase, the bacterial enzyme that catalyzes the reduction of dinitrogen (N2) to ammonia. In nitrogen-fixing and nodulating alpha-rhizobia, homocitrate is usually provided to bacteroids in root nodules by their plant host. In contrast, non-nodulating free-living diazotrophs encode the homocitrate synthase (NifV) and reduce N2 in nitrogen-limiting free-living conditions. Paraburkholderia phymatum STM815 is a beta-rhizobial strain, which can enter symbiosis with a broad range of legumes, including papilionoids and mimosoids. In contrast to most alpha-rhizobia, which lack nifV, P. phymatum harbors a copy of nifV on its symbiotic plasmid. We show here that P. phymatum nifV is essential for nitrogenase activity both in root nodules of papilionoid plants and in free-living growth conditions. Notably, nifV was dispensable in nodules of Mimosa pudica despite the fact that the gene was highly expressed during symbiosis with all tested papilionoid and mimosoid plants. A metabolome analysis of papilionoid and mimosoid root nodules infected with the P. phymatum wild-type strain revealed that among the approximately 400 measured metabolites, homocitrate and other metabolites involved in lysine biosynthesis and degradation have accumulated in all plant nodules compared to uninfected roots, suggesting an important role of these metabolites during symbiosis.


Assuntos
Proteínas de Bactérias/metabolismo , Burkholderiaceae/enzimologia , Fabaceae/microbiologia , Nitrogenase/metabolismo , Oxo-Ácido-Liases/metabolismo , Simbiose , Burkholderiaceae/genética , Genoma Bacteriano , Proteínas de Fluorescência Verde/metabolismo , Interações Hospedeiro-Patógeno , Funções Verossimilhança , Metaboloma , Filogenia , Nódulos Radiculares de Plantas/metabolismo , Nódulos Radiculares de Plantas/microbiologia
19.
Microbes Environ ; 36(1)2021.
Artigo em Inglês | MEDLINE | ID: mdl-33716243

RESUMO

Nitrogen fixing symbiosis between rhizobia and legumes contributes significant amounts of N to agricultural and natural environments. In natural soils, rhizobia compete with indigenous bacterial communities to colonize legume roots, which leads to symbiotic interactions. However, limited information is currently available on the effects of the rhizobial symbiont on the resident microbial community in the legume rhizosphere, rhizoplane, and endosphere, which is partly due to the presence of native nodulating rhizobial strains. In the present study, we used a symbiotic system comprised of Paraburkholderia phymatum and Mimosa pudica to examine the interaction of an inoculant strain with indigenous soil bacteria. The effects of a symbiont inoculation on the native bacterial community was investigated using high throughput sequencing and an analysis of 16S rRNA gene amplicons. The results obtained revealed that the inoculation induced significant alterations in the microbial community present in the rhizoplane+endosphere of the roots, with 13 different taxa showing significant changes in abundance. No significant changes were observed in the rhizospheric soil. The relative abundance of P. phymatum significantly increased in the rhizoplane+endosphere of the root, but significant decreased in the rhizospheric soil. While the rhizosphere, rhizoplane, and root endosphere contained a wide diversity of bacteria, the nodules were predominantly colonized by P. phymatum. A network analysis revealed that the operational taxonomic units of Streptomyces and Phycicoccus were positively associated with P. phymatum as potential keystone taxa. Collectively, these results suggest that the success of an inoculated symbiont depends on its ability to colonize the roots in the face of competition by other soil bacteria. A more detailed understanding of the mechanisms by which an inoculated strain colonizes its plant host is crucial for realizing the full potential of microbial inoculants in sustainable agriculture.


Assuntos
Inoculantes Agrícolas/crescimento & desenvolvimento , Burkholderiaceae/crescimento & desenvolvimento , Mimosa/microbiologia , Microbiologia do Solo , Inoculantes Agrícolas/classificação , Inoculantes Agrícolas/genética , Inoculantes Agrícolas/isolamento & purificação , Burkholderiaceae/classificação , Burkholderiaceae/genética , Burkholderiaceae/isolamento & purificação , Microbiota , Mimosa/crescimento & desenvolvimento , Filogenia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , Rizosfera
20.
Appl Microbiol Biotechnol ; 105(7): 2967-2977, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33687503

RESUMO

Lignin bio-valorization is an emerging field of applied biotechnology and has not yet been studied at low temperatures. Paraburkholderia aromaticivorans AR20-38 was examined for its potential to degrade six selected lignin monomers (syringic acid, p-coumaric acid, 4-hydroxybenzoic acid, ferulic acid, vanillic acid, benzoic acid) from different upper funneling aromatic pathways. The strain degraded four of these compounds at 10°C, 20°C, and 30°C; syringic acid and vanillic acid were not utilized as sole carbon source. The degradation of 5 mM and 10 mM ferulic acid was accompanied by the stable accumulation of high amounts of the value-added product vanillic acid (85-89% molar yield; 760 and 1540 mg l-1, respectively) over the whole temperature range tested. The presence of essential genes required for reactions in the upper funneling pathways was confirmed in the genome. This is the first report on biodegradation of lignin monomers and the stable vanillic acid production at low and moderate temperatures by P. aromaticivorans. KEY POINTS: • Paraburkholderia aromaticivorans AR20-38 successfully degrades four lignin monomers. • Successful degradation study at low (10°C) and moderate temperatures (20-30°C). • Biotechnological value: high yield of vanillic acid produced from ferulic acid.


Assuntos
Lignina , Ácido Vanílico , Burkholderiaceae , Ácidos Cumáricos , Florestas , Solo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...