RESUMO
An aerobic, Gram-stain-negative, rod-shaped, non-motile, mesophilic soil bacterium, strain WS5A3pT, was isolated from a pesticide burial site in north-west Poland. The strain grew at 12-37 °C, at pH 8-9 and with 0-2â% (w/v) NaCl. The main fatty acids detected in WS5A3pT were summed feature 3, summed feature 8 and C16â:â0. The major respiratory quinone was Q-10 and major polar lipids were phosphatidylethanolamine, sphingoglycolipid and phosphatidylglycerol. The G+C content of the genome was 65.1 mol%. Phylogenetic pairwise distance analysis of the 16S rRNA gene placed this strain within the genus Sphingopyxis, with the highest similarity to Sphingopyxis witflariensis W-50T (98.8â%), Sphingopyxis bauzanensis BZ30T and Sphingopyxis ginsengisoli Gsoil 250T (98.3â%) and Sphingopyxis granuli NBRC 100800T (98.09â%). Genomic similarity analyses using ANIb and dDDH algorithms indicated levels of similarity of 81.44, 80.84 and 81.16â% between WS5A3pT and S. witflariensis, S. bauzanensisand S. granuli, respectively for average nucleotide identity and 25.90, 25.00 and 26.10â% for digital DNA-DNA hybridization. Based on the phylogenetic and phenotypic data, strain WS5A3pT should be considered as a representative of a novel Sphingopyxis species. The name Sphingopyxis lindanitolerans sp. nov. is proposed with the type strain WS5A3pT (=DSM 106274T=PCM 2932T).
Assuntos
Resíduos Perigosos , Praguicidas , Filogenia , Microbiologia do Solo , Sphingomonadaceae/classificação , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , Fosfolipídeos/química , Polônia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Sphingomonadaceae/genética , Sphingomonadaceae/isolamento & purificação , Ubiquinona/análogos & derivados , Ubiquinona/químicaRESUMO
BACKGROUND: Although interactions between microorganisms involved in biogas production are largely uncharted, it is commonly accepted that methanogenic Archaea are essential for the process. Methanogens thrive in various environments, but the most extensively studied communities come from biogas plants. In this study, we employed a metagenomic analysis of deeply sequenced methanogenic communities, which allowed for comparison of taxonomic and functional diversity as well as identification of microorganisms directly involved in various stages of methanogenesis pathways. RESULTS: A comprehensive metagenomic approach was used to compare seven environmental communities, originating from an agricultural biogas plant, cattle-associated samples, a lowland bog, sewage sludge from a wastewater treatment plant and sediments from an ancient gold mine. In addition to the native consortia, two laboratory communities cultivated on maize silage as the sole substrate were also analyzed. Results showed that all anaerobic communities harbored genes of all known methanogenesis pathways, but their abundance varied greatly between environments and that genes were encoded by different methanogens. Identification of microorganisms directly involved in different stages of methane production revealed that hydrogenotrophic methanogens, such as Methanoculleus, Methanobacterium, Methanobrevibacter, Methanocorpusculum or Methanoregula, predominated in most native communities, whereas acetoclastic Methanosaeta seemed to be the key methanogen in the wastewater treatment plant. Furthermore, in many environments, the methylotrophic pathway carried out by representatives of Methanomassiliicoccales, such as Candidatus Methanomethylophilus and Candidatus Methanoplasma, seemed to play an important role in methane production. In contrast, in stable laboratory reactors substrate versatile Methanosarcina predominated. CONCLUSIONS: The metagenomic approach presented in this study allowed for deep exploration and comparison of nine environments in which methane production occurs. Different abundance of methanogenesis-related functions was observed and the functions were analyzed in the phylogenetic context in order to identify microbes directly involved in methane production. In addition, a comparison of two metagenomic analytical tools, MG-RAST and MetAnnotate, revealed that combination of both allows for a precise characterization of methanogenic communities.
Assuntos
Sequenciamento de Nucleotídeos em Larga Escala/métodos , Metagenômica/métodos , Metano/síntese químicaRESUMO
The conjugation of 4-N-(3-aminopropanyl)-2'-deoxy-2',2'-difluorocytidine with 2-(p-isothiocyanatobenzyl)-1,4,7-triazacyclononane-1,4,7-triacetic acid (SCN-Bn-NOTA) ligand in 0.1â¯M Na2CO3 buffer (pH 11) at ambient temperature provided 4-N-alkylgemcitabine-NOTA chelator. Incubation of latter with excess of gallium(III) chloride (GaCl3) (0.6â¯N AcONa/H2O, pHâ¯=â¯9.3) over 15â¯min gave gallium 4-N-alkylgemcitabine-NOTA complex which was characterized by HRMS. Analogous [68Ga]-complexation of 4-N-alkylgemcitabine-NOTA conjugate proceeded with high labeling efficiency (94%-96%) with the radioligand almost exclusively found in the aqueous layer (â¼95%). The high polarity of the gallium 4-N-alkylgemctiabine-NOTA complex resulted in rapid renal clearance of the 68Ga-labelled radioligand in BALB/c mice.
Assuntos
Quelantes/farmacologia , Desoxicitidina/análogos & derivados , Radioisótopos de Gálio/química , Compostos Heterocíclicos/farmacologia , Compostos Radiofarmacêuticos/farmacologia , Animais , Quelantes/síntese química , Desoxicitidina/síntese química , Desoxicitidina/farmacologia , Compostos Heterocíclicos/síntese química , Compostos Heterocíclicos com 1 Anel , Camundongos Endogâmicos BALB C , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos/síntese química , GencitabinaRESUMO
The main aim of this study was to evaluate the effect of the source of microorganisms on the selection of hydrolytic consortia dedicated to anaerobic digestion of maize silage. The selection process was investigated based on the analysis of changes in the hydrolytic activity and the diversity of microbial communities derived from (i) a hydrolyzer of a commercial agricultural biogas plant, (ii) cattle slurry and (iii) raw sewage sludge, during a series of 10 passages. Following the selection process, the adapted consortia were thoroughly analyzed for their ability to utilize maize silage and augmentation of anaerobic digestion communities. The results of selection of the consortia showed that every subsequent passage of each consortium leads to their adaptation to degradation of maize silage, which was manifested by the increased hydrolytic activity of the adapted consortia. Biodiversity analysis (based on the 16S rDNA amplicon sequencing) confirmed the changes microbial community of each consortium, and showed that after the last (10th) passage all microbial communities were dominated by the representatives of Lactobacillaceae, Prevotellaceae, Veillonellaceae. The results of the functional analyses showed that the adapted consortia improved the efficiency of maize silage degradation, as indicated by the increase in the concentration of glucose and volatile fatty acids (VFAs), as well as the soluble chemical oxygen demand (sCOD). Moreover, bioaugmentation of anaerobic digestion communities by the adapted hydrolytic consortia increased biogas yield by 10-29%, depending on the origin of the community. The obtained results also indicate that substrate input (not community origin) was the driving force responsible for the changes in the community structure of hydrolytic consortia dedicated to anaerobic digestion.
Assuntos
Anaerobiose , Biodegradação Ambiental , Consórcios Microbianos , Silagem/microbiologia , Zea mays/química , Zea mays/microbiologia , Animais , Biodiversidade , Bovinos , Hidrólise , Metagenômica/métodos , Metano/biossínteseRESUMO
4-C-Alkyl/aryl-S-ribosylhomocysteine (SRH) analogues were prepared by coupling of homocysteine with 4-substituted ribofuranose derivatives. The diastereoselective incorporation of the methyl substituent into the 4 position of the ribose ring was accomplished by addition of methylmagnesium bromide to the protected ribitol-4-ulose yielding the 4-C-methylribitol in 85% yield as single 4R diastereomer. The 4-C hexyl, octyl, vinyl, and aryl ribitols were prepared analogously. Chelation controlled addition of a carbanion to ketones from the (Si-face) was responsible for the observed stereochemical outcome. Oxidation of the primary alcohol of the 4-C ribitols with the catalytic amount of tetrapropylammonium perruthenate in the presence of N-methylmorpholine N-oxide produced 4-C-alkylribono-1,4-lactones in high yields. Mesylation of the latter compounds at the 5-hydroxyl position and treatment with a protected homocysteine thiolate afforded protected 4-C-alkyl/aryl-SRH analogues as the lactones. Reduction with lithium triethylborohydride and successive global deprotections with TFA afforded 4-C-alkyl/aryl SRH analogues. These analogues might impede the S-ribosylhomocysteinase(LuxS)-catalyzed reaction by preventing ß-elimination of a homocysteine molecule, and thus depleting the production of quorum sensing signaling molecule AI-2.
RESUMO
Calmyrin1 (CaMy1) is an EF-hand Ca(2+)-binding protein expressed in several cell types, including brain neurons. Using a yeast two-hybrid screen of a human fetal brain cDNA library, we identified SCG10 protein (stathmin2) as a CaMy1 partner. SCG10 is a microtubule-destabilizing factor involved in neuronal growth during brain development. We found increased mRNA and protein levels of CaMy1 during neuronal development, which paralleled the changes in SCG10 levels. In developing primary rat hippocampal neurons in culture, CaMy1 and SCG10 colocalized in cell soma, neurites, and growth cones. Pull-down, coimmunoprecipitation, and proximity ligation assays demonstrated that the interaction between CaMy1 and SCG10 is direct and Ca(2+)-dependent in vivo and requires the C-terminal domain of CaMy1 (residues 99-192) and the N-terminal domain of SCG10 (residues 1-35). CaMy1 did not interact with stathmin1, a protein that is homologous with SCG10 but lacks the N-terminal domain characteristic of SCG10. CaMy1 interfered with SCG10 inhibitory activity in a microtubule polymerization assay. Moreover, CaMy1 overexpression inhibited SCG10-mediated neurite outgrowth in nerve growth factor (NGF)-stimulated PC12 cells. This CaMy1 activity did not occur when an N-terminally truncated SCG10 mutant unable to interact with CaMy1 was expressed. Altogether, these data suggest that CaMy1 via SCG10 couples Ca(2+) signals with the dynamics of microtubules during neuronal outgrowth in the developing brain. This article is part of a Special Issue entitled: 11th European Symposium on Calcium.
Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Proteínas de Transporte/metabolismo , Proteínas de Membrana/metabolismo , Neuritos/metabolismo , Animais , Cálcio/metabolismo , Proteínas de Ligação ao Cálcio/química , Proteínas de Ligação ao Cálcio/genética , Diferenciação Celular/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Células HeLa , Hipocampo/citologia , Hipocampo/embriologia , Humanos , Proteínas de Membrana/química , Proteínas dos Microtúbulos , Microtúbulos/efeitos dos fármacos , Microtúbulos/metabolismo , Fator de Crescimento Neural/farmacologia , Neuritos/efeitos dos fármacos , Células PC12 , Polimerização/efeitos dos fármacos , Ligação Proteica/efeitos dos fármacos , Estrutura Terciária de Proteína , Transporte Proteico/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Estatmina , Tubulina (Proteína)/metabolismoRESUMO
Model 3'-azido-3'-deoxynucleosides with thiol or vicinal dithiol substituents at C2' or C5' were synthesized to study reactions postulated to occur during inhibition of ribonucleotide reductases by 2'-azido-2'-deoxynucleotides. Esterification of 5'-(tert-butyldiphenylsilyl)-3'-azido-3'-deoxyadenosine and 3'-azido-3'-deoxythymidine (AZT) with 2,3-S-isopropylidene-2,3-dimercaptopropanoic acid or N-Boc-S-trityl-L-cysteine and deprotection gave 3'-azido-3'-deoxy-2'-O-(2,3-dimercaptopropanoyl or cysteinyl)adenosine and the 3'-azido-3'-deoxy-5'-O-(2,3-dimercaptopropanoyl or cysteinyl)thymidine analogs. Density functional calculations predicted that intramolecular reactions between generated thiyl radicals and an azido group on such model compounds would be exothermic by 33.6-41.2 kcal/mol and have low energy barriers of 10.4-13.5 kcal/mol. Reduction of the azido group occurred to give 3'-amino-3'-deoxythymidine, which was postulated to occur with thiyl radicals generated by treatment of 3'-azido-3'-deoxy-5'-O-(2,3-dimercaptopropanoyl)thymidine with 2,2'-azobis-(2-methyl-2-propionamidine) dihydrochloride. Gamma radiolysis of N(2)O-saturated aqueous solutions of AZT and cysteine produced 3'-amino-3'-deoxythymidine and thymine most likely by both radical and ionic processes.
RESUMO
LuxS (S-ribosylhomocysteinase) catalyzes the cleavage of the thioether linkage of S-ribosylhomocysteine (SRH) to produce homocysteine and 4,5-dihydroxy-2,3-pentanedione (DPD), the precursor to a small signaling molecule that mediates interspecies bacterial communication called autoinducer 2 (AI-2). Inhibitors of LuxS should interfere with bacterial interspecies communication and potentially provide a novel class of antibacterial agents. In this work, SRH analogues containing substitution of a nitrogen atom for the endocyclic oxygen as well as various deoxyriboses were synthesized and evaluated for LuxS inhibition. Two of the [4-aza]SRH analogues showed modest competitive inhibition (K(I) â¼40 µM), while most of the others were inactive. One compound that contains a hemiaminal moiety exhibited time-dependent inhibition, consistent with enzyme-catalyzed ring opening and conversion into a more potent species (K(I)(∗)=3.5 µM). The structure-activity relationship of the designed inhibitors highlights the importance of both the homocysteine and ribose moieties for high-affinity binding to LuxS active site.
Assuntos
Bacillus subtilis/enzimologia , Proteínas de Bactérias/antagonistas & inibidores , Liases de Carbono-Enxofre/antagonistas & inibidores , Homocisteína/análogos & derivados , Ribose/química , Proteínas de Bactérias/metabolismo , Liases de Carbono-Enxofre/metabolismo , Relação Dose-Resposta a Droga , Homocisteína/síntese química , Homocisteína/química , Homocisteína/farmacologia , Estrutura Molecular , Ribose/análogos & derivados , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
Quorum sensing (QS) is a population-dependent signaling process bacteria use to control multiple processes including virulence that is critical for establishing infection. The most common QS signaling molecule used by Gram-negative bacteria are acylhomoserine lactones. The development of non-native acylhomoserine lactone (AHL) ligands has emerged as a promising new strategy to inhibit QS in Gram-negative bacteria. In this work, we have synthesized a set of optically pure γ-lactams and their reduced cyclic azahemiacetal analogues, bearing the additional alkylthiomethyl substituent, and evaluated their effect on the AHL-dependent Pseudomonas aeruginosa las and rhl QS pathways. The concentration of these ligands and the simple structural modification such as the length of the alkylthio substituent has notable effect on activity. The γ-lactam derivatives with nonylthio or dodecylthio chains acted as inhibitors of las signaling with moderate potency. The cyclic azahemiacetal with shorter propylthio or hexylthio substituent was found to strongly inhibit both las and rhl signaling at higher concentrations while the propylthio analogue strongly stimulated the las QS system at lower concentrations.
Assuntos
Acetais/farmacologia , Lactamas/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Percepção de Quorum/efeitos dos fármacos , Acetais/síntese química , Acetais/química , Relação Dose-Resposta a Droga , Lactamas/síntese química , Lactamas/química , Estrutura Molecular , Pseudomonas aeruginosa/metabolismo , Transdução de Sinais/efeitos dos fármacos , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
In this study,we used publicly available data from the Centrum e-Zdrowia (CeZ) Polish Databank proposing a possible correlation between influenza vaccination and mortality due to COVID-19. We limited our search to the patients with positive COVID19 laboratory tests from 1 January 2020 to 31 March 2021 and who filled a prescription for any influenza vaccine during the 2019-2020 influenza season. In total, we included 116,277 patients and used a generalized linear model to analyze the data.We found out that patients aged 60+ who received an influenza vaccination have a lower probability of death caused by COVID-19 in comparison to unvaccinated, and the magnitude of this difference grows with age. For people below 60 years old, we did not observe an influence of the vaccination. Our results suggest a potential protective effect of the influenza vaccine on COVID-19 mortality of the elderly. Administration of the influenza vaccine before the influenza season would reduce the burden of increased influenza incidence, the risk of influenza and COVID19 coinfection and render the essential medical resources accessible to cope with another wave of COVID-19. To our knowledge, this is the first study showing a correlation between influenza vaccination and the COVID-19 mortality rate in Poland.
RESUMO
In this work, electron-induced site-specific formation of neutral π-type aminyl radicals (RNH·) and their reactions with pyrimidine nucleoside analogs azidolabeled at various positions in the sugar moiety, e.g., at 2'-, 3'-, 4'-, and 5'- sites along with a model compound 3-azido-1-propanol (3AZPrOH), were investigated. Electron paramagnetic resonance (EPR) studies confirmed the site and mechanism of RNH· formation via dissociative electron attachment-mediated loss of N2 and subsequent facile protonation from the solvent employing the 15N-labeled azido group, deuterations at specific sites in the sugar and base, and changing the solvent from H2O to D2O. Reactions of RNH· were investigated employing EPR by warming these samples from 77 K to ca. 170 K. RNH· at a primary carbon site (5'-azido-2',5'-dideoxyuridine, 3AZPrOH) facilely converted to a σ-type iminyl radical (RâN·) via a bimolecular H-atom abstraction forming an α-azidoalkyl radical. RNH· when at a secondary carbon site (e.g., 2'-azido-2'-deoxyuridine) underwent bimolecular electrophilic addition to the C5âC6 double bond of a proximate pyrimidine base. Finally, RNH· at tertiary alkyl carbon (4'-azidocytidine) underwent little reaction. These results show the influence of the stereochemical and electronic environment on RNH· reactivity and allow the selection of those azidonucleosides that would be most effective in augmenting cellular radiation damage.
Assuntos
Elétrons , Nucleosídeos , Espectroscopia de Ressonância de Spin Eletrônica , Radicais Livres , Pirimidinas , AçúcaresRESUMO
S-Ribosylhomocysteinase (LuxS) cleaves the thioether bond in S-ribosylhomocysteine (SRH) to produce homocysteine (Hcys) and 4,5-dihydroxy-2,3-pentanedione (DPD), the precursor of the type II bacterial quorum sensing molecule (AI-2). The catalytic mechanism of LuxS comprises three distinct reaction steps. The first step involves carbonyl migration from the C1 carbon of ribose to C2 and the formation of a 2-ketone intermediate. The second step shifts the C=O group from the C2 to C3 position to produce a 3-ketone intermediate. In the final step, the 3-ketone intermediate undergoes a beta-elimination reaction resulting in the cleavage of the thioether bond. In this work, the 3-ketone intermediate was chemically synthesized and shown to be chemically and kinetically competent in the LuxS catalytic pathway. Substrate analogues halogenated at the C3 position of ribose were synthesized and reacted as time-dependent inhibitors of LuxS. The time dependence was caused by enzyme-catalyzed elimination of halide ions. Examination of the kinetics of halide release and decay of the 3-ketone intermediate catalyzed by wild-type and mutant LuxS enzymes revealed that Cys-84 is the general base responsible for proton abstraction in the three reaction steps, whereas Glu-57 likely facilitates substrate binding and proton transfer during catalysis.
Assuntos
Proteínas de Bactérias/análise , Proteínas de Bactérias/metabolismo , Biocatálise , Liases de Carbono-Enxofre/análise , Liases de Carbono-Enxofre/metabolismo , Domínio Catalítico , Homocisteína/química , Homocisteína/metabolismo , Cetonas/química , Cetonas/metabolismo , Cinética , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Estrutura Molecular , Especificidade por Substrato , Fatores de TempoRESUMO
Calmyrin2 (CaMy2, Cib2) is a novel EF-hand calcium-binding protein found recently in skeletal muscles. CaMy2 mRNA was also detected in brain, but nothing is known about CaMy2 protein localization and properties in the brain. We report cloning and characterization of CaMy2 in rat brain: its expression pattern, intracellular localization and biochemical features. CaMy2 binds Ca2+ and exhibits Ca2+/conformational switch. Moreover, CaMy2 undergoes N-myristoylation without Ca2+/myristoyl switch, is membrane-associated and localizes in neurons together with Golgi apparatus and dendrite markers. CaMy2 transcript and protein are present mainly in the hippocampus and cortex. In cultured hippocampal neurons, CaMy2 is induced upon neuronal activation. Most prominent increase in CaMy2 protein (7-fold), and mRNA (2-fold) occurs upon stimulation of NMDA receptor (NMDAR). The induction is blocked by translation inhibitors, specific antagonists of NMDAR, the Ca2+-chelator BAPTA, and inhibitors of ERK1/2 and PKC, kinases transmitting NMDAR-linked Ca2+ signal. Our results show that CaMy2 level is controlled by NMDAR and Ca2+ and suggest CaMy2 role in Ca2+ signaling underlying NMDAR activation.
Assuntos
Encéfalo/metabolismo , Sinalização do Cálcio/fisiologia , Proteínas de Ligação ao Cálcio/química , Proteínas de Ligação ao Cálcio/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Animais , Células COS , Proteínas de Ligação ao Cálcio/genética , Córtex Cerebral/metabolismo , Chlorocebus aethiops , Expressão Gênica , Hipocampo/metabolismo , Hibridização In Situ , Técnicas In Vitro , Masculino , Miristatos/metabolismo , Conformação Proteica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismoRESUMO
S-ribosylhomocysteinase (LuxS) catalyzes the cleavage of the thioether bond of S-ribosylhomocysteine (SRH) to produce homocysteine and 4,5-dihydroxy-2,3-pentanedione (DPD), which is the precursor of type 2 autoinducer for bacterial cell-cell communication. In this work, we have synthesized several SRH analogues modified at the ribose C3 position as potential inhibitors of LuxS. While removal or methylation of the C3-OH resulted in simple competitive inhibitors of moderate potency, inversion of the C3 stereochemistry or substitution of fluorine for C3-OH resulted in slow-binding inhibitors of improved potency. The most potent inhibitor showed a K(I)(*) value of 0.43 microM.
Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/metabolismo , Liases de Carbono-Enxofre/antagonistas & inibidores , Liases de Carbono-Enxofre/metabolismo , Homocisteína/análogos & derivados , Bacillus subtilis/efeitos dos fármacos , Bacillus subtilis/metabolismo , Homocisteína/química , Homocisteína/farmacologia , Ribose/química , Relação Estrutura-AtividadeRESUMO
Sphingopyxis inhabit diverse environmental niches, including marine, freshwater, oceans, soil and anthropogenic sites. The genus includes 20 phylogenetically distinct, valid species, but only a few with a sequenced genome. In this work, we analyzed the nearly complete genome of the newly described species, Sphingopyxislindanitolerans, and compared it to the other available Sphingopyxis genomes. The genome included 4.3 Mbp in total and consists of a circular chromosome, and two putative plasmids. Among the identified set of lin genes responsible for γ-hexachlorocyclohexane pesticide degradation, we discovered a gene coding for a new isoform of the LinA protein. The significant potential of this species in the remediation of contaminated soil is also correlated with the fact that its genome encodes a higher number of enzymes potentially involved in aromatic compound degradation than for most other Sphingopyxis strains. Additional analysis of 44 Sphingopyxis representatives provides insights into the pangenome of Sphingopyxis and revealed a core of 734 protein clusters and between four and 1667 unique proteins per genome.
Assuntos
Genoma Bacteriano , Hexaclorocicloexano/metabolismo , Praguicidas/metabolismo , Sphingomonadaceae/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Biodegradação Ambiental , Sphingomonadaceae/enzimologia , Sphingomonadaceae/metabolismoRESUMO
Biochemical, physiological and genomic comparisons of two Pseudomonas strains, assigned previously to the Pseudomonas jessenii subgroup, which are efficient SDS-degraders were carried out. A GO enrichment analysis showed that the genomes of SDS-degraders encode more genes connected with bacterial cell wall biosynthesis and alkanesulfonate monooxygenase activity than their closest relatives from the P. jessenii subgroup. A transcriptomic analysis of the most promising strain exposed to detergent suggests that although SDS can be later utilized as a carbon source, in early stages it influences cell envelope integrity, causing a global stress response followed by cell wall modification and induction of repair mechanisms. Genomes of the analyzed strains from P. jessenii group encode multiple putative sulfatases and their enzymatic activity was experimentally verified, which led to the identification of three novel enzymes exhibiting activity toward SDS. Two of the novel alkylsulfatases showed their highest activity at pH 8.0 and the temperature of 60°C or 70°C. One of the enzymes retained its activity even after 1 h of incubation at 60°C. Ions like K+ and Mg2+ enhanced enzymatic activity of both proteins, whereas Cu2+ or EDTA had inhibitory effects.
RESUMO
Pseudomonas are known from their flexible degradation capabilities and their engagement in xenobiotic biotransformation and bioremediation in habitats like soil, active sludge, plant surfaces, and freshwater or marine environments. Here we present taxonomic characterization of three efficient sodium dodecyl sulfate degrading strains: AP3_10, AP3_20 and AP3_22T belonging to the genus Pseudomonas, recently isolated from peaty soil used in a biological wastewater treatment plant. Sequence analyses of 16S rRNA and housekeeping genes: gyrB, rpoD and rpoB showed that the three closely related isolates classify within the Pseudomonas jessenii subgroup. ANIb or dDDH genomic comparisons of AP3_22T (type strain DSM 105098T=PCM 2904T) supported by biochemical tests showed that the isolates differ significantly from their closest relatives. The combined genotypic, phenotypic and chemotaxonomic data strongly support the classification of the three strains: AP3_10, AP3_20 and AP3_22T as a novel species of Pseudomonas, for which we propose the name Pseudomonas laurylsulfatovorans sp. nov. with AP3_22T as the type strain.
Assuntos
Pseudomonas , Dodecilsulfato de Sódio/metabolismo , Águas Residuárias/microbiologia , Purificação da Água , Composição de Bases , Biodegradação Ambiental , DNA Bacteriano/genética , Ácidos Graxos/análise , Genes Essenciais/genética , Tipagem Molecular , Filogenia , Pseudomonas/classificação , Pseudomonas/genética , Pseudomonas/isolamento & purificação , Pseudomonas/metabolismo , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Solo/química , Microbiologia do SoloRESUMO
Microorganisms classified in to the Pseudomonas genus are a ubiquitous bacteria inhabiting variety of environmental niches and have been isolated from soil, sediment, water and different parts of higher organisms (plants and animals). Members of this genus are known for their metabolic versatility and are able to utilize different chemical compounds as a source of carbon, nitrogen or phosphorus, which makes them an interesting microorganism for bioremediation or bio-transformation. Moreover, Pseudomonas sp. has been described as a microorganism that can easily adapt to new environmental conditions due to its resistance to the presence of high concentrations of heavy metals or chemical pollution. Here we present the isolation and analysis of Pseudomonas silesiensis sp. nov. strain A3T isolated from peaty soil used in a biological wastewater treatment plant exploited by a pesticide packaging company. Phylogenetic MLSA analysis of 4 housekeeping genes (16S rRNA, gyrB, rpoD and rpoB), complete genome sequence comparison (ANIb, Tetranucleotide identity, digital DDH), FAME analysis, and other biochemical tests indicate the A3T strain (type strain PCM 2856T=DSM 103370T) differs significantly from the closest relative species and therefore represents a new species within the Pseudomonas genus. Moreover, bioinformatic analysis of the complete sequenced genome showed that it consists of 6,823,539bp with a 59.58mol% G+C content and does not contain any additional plasmids. Genome annotation predicted the presence of 6066 genes, of which 5875 are coding proteins and 96 are RNA genes.
Assuntos
Genoma Bacteriano , Pseudomonas/classificação , Pseudomonas/isolamento & purificação , Esgotos/microbiologia , Composição de Bases , Agentes de Controle Biológico , Análise por Conglomerados , DNA Girase/genética , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , RNA Polimerases Dirigidas por DNA/genética , Poluentes Ambientais , Anotação de Sequência Molecular , Tipagem de Sequências Multilocus , Filogenia , Pseudomonas/genética , Pseudomonas/crescimento & desenvolvimento , RNA Ribossômico 16S/genética , Fator sigma/genética , Sequenciamento Completo do GenomaRESUMO
The interaction between the EF-hand Ca(2+)-binding protein calmyrin and presenilin 2 (PS2) has been suggested to play a role in Alzheimer's disease (AD). We now report that calmyrin binds specifically endogenous PS2 and not PS1. However, binding appears to be Ca(2+)-independent and calmyrin does not exhibit a Ca(2+)-dependent translocation to intracellular membranes as demonstrated in a Ca(2+)-myristoyl switch assay. Moreover, calmyrin is only present at very low levels in brain areas associated with the onset of AD. In rat, forebrain calmyrin is localized only in a subset of principal neurons, similarly as in human forebrain. Finally, subcellular fractionation demonstrates only a limited overlap of calmyrin and PS2 at neuronal membranes. We therefore conclude that calmyrin will not contribute significantly as a Ca(2+)-sensor that transduces Ca(2+)-signaling events to PS2 in forebrain.
Assuntos
Doença de Alzheimer/metabolismo , Sinalização do Cálcio , Proteínas de Ligação ao Cálcio/metabolismo , Cálcio/metabolismo , Perfilação da Expressão Gênica , Proteínas de Membrana/metabolismo , Prosencéfalo/metabolismo , Animais , Células COS , Chlorocebus aethiops , Células HeLa , Humanos , Membranas Intracelulares/metabolismo , Presenilina-2 , Ligação Proteica , Ratos , Ratos Wistar , Proteínas Recombinantes de Fusão/metabolismoRESUMO
We present here the draft genome sequence of Sphingopyxis bauzanensis DSM 22271. The assembly contains 4,258,005 bp in 28 scaffolds and has a GC content of 63.3%. A series of specific genes involved in the catabolism or transport of aromatic compounds was identified.