Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 83
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Anesth Analg ; 134(2): 348-356, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33439606

RESUMO

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has affected the personal and professional lives of all health care workers. Anesthesiologists frequently perform virus-aerosolizing procedures (eg, intubation and extubation) that place them at increased risk of infection. We sought to determine how the initial COVID-19 outbreak affected members of the Society for Pediatric Anesthesia (SPA) on both personal and professional levels. Specifically, we examined the potential effects of gender and age on personal stress, burnout, sleep deprivation, anxiety, depression, assessed job satisfaction, and explored financial impact. METHODS: After receiving approval from the SPA Committees for Research and Quality and Safety and the Colorado Multiple Institutional Review Board, we e-mailed a questionnaire to all 3245 SPA members. The survey included 22 questions related to well-being and 13 questions related to effects of COVID-19 on current and future practice, finances, retirement planning, academic time and productivity, and clinical and home responsibilities. To address low initial response rates and quantify nonresponse bias, we sent a shortened follow-up survey to a randomly selected subsample (n = 100) of SPA members who did not respond to the initial survey. Response differences between the 2 cohorts were determined. RESULTS: A total of 561 (17%) members responded to the initial questionnaire. Because of COVID-19, 21.7% of respondents said they would change their clinical responsibilities, and 10.6% would decrease their professional working time. Women were more likely than men to anticipate a future COVID-19-related job change (odds ratio [OR] = 1.92, 95% confidence interval [CI], 1.12-2.63; P = .011), perhaps because of increased home responsibilities (OR = 2.63, 95% CI, 1.74-4.00; P < .001). Additionally, 14.2% of respondents planned to retire early, and 11.9% planned to retire later. Women and non-White respondents had higher likelihoods of burnout on univariate analysis (OR = 1.75, 95% CI, 1.06-2.94, P = .026 and OR = 1.82, 95% CI, 1.08-3.04, P = .017, respectively), and 25.1% of all respondents felt socially isolated. In addition, both changes in retirement planning and future occupational planning were strongly associated with total job satisfaction scores (both P < .001). CONCLUSIONS: The COVID-19 pandemic has affected the personal and professional lives of pediatric anesthesiologists, albeit not equally, as women and non-Whites have been disproportionately impacted. The pandemic has significantly affected personal finances, home responsibilities, and retirement planning; reduced clinical and academic practice time and responsibilities; and increased feelings of social isolation, stress, burnout, and depression/anxiety.


Assuntos
Anestesia/psicologia , Anestesiologistas/psicologia , Esgotamento Profissional/psicologia , COVID-19/psicologia , Pediatria , Inquéritos e Questionários , Adulto , Anestesia/tendências , Anestesiologistas/tendências , Esgotamento Profissional/epidemiologia , COVID-19/epidemiologia , Feminino , Humanos , Satisfação no Emprego , Masculino , Pessoa de Meia-Idade , Exposição Ocupacional/efeitos adversos , Exposição Ocupacional/prevenção & controle , Pediatria/tendências , Aposentadoria/tendências , Sociedades Médicas/tendências
2.
Anesth Analg ; 132(6): 1518-1526, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33543867

RESUMO

BACKGROUND: Although the package insert clearly states that "the safety and efficacy of sugammadex in pediatric patients have not been established," we hypothesized that sugammadex is used widely in pediatric anesthetic practice supplanting neostigmine as the primary drug for antagonizing neuromuscular blockade (NMB). Additionally, we sought to identify the determinants by which pediatric anesthesiologists choose reversal agents and if and how they assess NMB in their practice. Finally, because of sugammadex's effects on hormonal contraception, we sought to determine whether pediatric anesthesiologists counseled postmenarchal patients on the need for additional or alternative forms of contraception and the risk of unintended pregnancy in the perioperative period. METHODS: We e-mailed a questionnaire to all 3245 members of the Society of Pediatric Anesthesia (SPA) requesting demographic data and attitudes regarding use of NMB agents, monitoring, and antagonism practices. To address low initial response rates and quantify nonresponse bias, we sent a shortened follow-up survey to a randomly selected subsample (n = 75) of SPA members who did not initially respond. Response differences between the 2 cohorts were determined. RESULTS: Initial questionnaire response rate was 13% (419 of 3245). Overall, 163 respondents (38.9%; 95% confidence interval [CI], 34.2-43.8) used sugammadex as their primary reversal agent, and 106 (25.2%; 95% CI, 21.2-30.0) used it exclusively. Respondents with ≤5 years of practice used sugammadex as their primary reversal agent more often than those with ≥6 years of practice (odds ratio [OR]: 2.08; 95% CI, 1.31-3.31; P = .001). This increased utilization remained after controlling for institutional restriction and practice type (adjusted OR [aOR]: 2.20; 95% CI, 1.38-3.54; P = .001). Only 40% of practitioners always assess NMB (train-of-four), and use was inversely correlated with years of practice (Spearman ρ = -0.11, P = .04). Anesthesiologists who primarily used sugammadex assess NMB less routinely (OR: 0.56; 95% CI, 0.34-0.90; P = .01). A slim majority (52.8%) used sugammadex for pediatric postmenarchal girls; those with less experience used it more commonly (P < .001). Thirty-eight percent did not discuss its effects on hormonal contraception with the patient and/or family, independent of anesthesiologist experience (P = .33) and practice location (P = .38). No significant differences were seen in demographics or practice responses between initial and follow-up survey respondents. CONCLUSIONS: Sugammadex is commonly used in pediatric anesthesia, particularly among anesthesiologists with fewer years of practice. Failure to warn postmenarchal adolescents of its consequences may result in unintended pregnancies. Finally, pediatric anesthesia training programs should emphasize objective monitoring of NMB, particularly with sugammadex use.


Assuntos
Monitorização Intraoperatória/normas , Bloqueio Neuromuscular/métodos , Fármacos Neuromusculares não Despolarizantes/administração & dosagem , Pediatria/normas , Sociedades Médicas/normas , Inquéritos e Questionários , Adulto , Anestesia/efeitos adversos , Anestesia/métodos , Anestesiologistas/normas , Anestesiologistas/tendências , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Intraoperatória/métodos , Bloqueio Neuromuscular/efeitos adversos , Pediatria/métodos , Sociedades Médicas/tendências , Sugammadex/administração & dosagem
3.
RNA ; 24(6): 769-777, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29487104

RESUMO

Prp8 is an essential protein that regulates spliceosome assembly and conformation during pre-mRNA splicing. Recent cryo-EM structures of the spliceosome model Prp8 as a scaffold for the spliceosome's catalytic U snRNA components. Using a new amino acid probing strategy, we identified a dynamic region in human Prp8 that is positioned to stabilize the pre-mRNA in the spliceosome active site through interactions with U5 snRNA. Mutagenesis of the identified Prp8 residues in yeast indicates a role in 5' splice site recognition. Genetic interactions with spliceosome proteins Isy1, which buttresses the intron branch point, and Snu114, a regulatory GTPase that directly contacts Prp8, further corroborate a role for the same Prp8 residues in substrate positioning and activation. Together the data suggest that adjustments in interactions between Prp8 and U5 snRNA help establish proper positioning of the pre-mRNA into the active site to enhance 5' splice site fidelity.


Assuntos
Precursores de RNA/genética , Sítios de Splice de RNA , RNA Nuclear Pequeno/genética , Proteínas de Ligação a RNA/metabolismo , Ribonucleoproteína Nuclear Pequena U4-U6/metabolismo , Ribonucleoproteína Nuclear Pequena U5/metabolismo , Saccharomyces cerevisiae/genética , Domínio Catalítico , Humanos , Proteínas de Ligação a RNA/genética , Ribonucleoproteína Nuclear Pequena U4-U6/genética , Ribonucleoproteína Nuclear Pequena U5/genética , Saccharomyces cerevisiae/metabolismo , Spliceossomos
4.
RNA Biol ; 16(10): 1346-1354, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31213125

RESUMO

Structural models of large and dynamic molecular complexes are appearing in increasing numbers, in large part because of recent technical advances in cryo-electron microscopy. However, the inherent complexity of such biological assemblies comprising dozens of moving parts often limits the resolution of structural models and leaves the puzzle as to how each functional configuration transitions to the next. Orthogonal biochemical information is crucial to understanding the molecular interactions that drive those rearrangements. We present a two-step method for chemical probing detected by tandem mass-spectrometry to globally assess the reactivity of lysine residues within purified macromolecular complexes. Because lysine side chains often balance the negative charge of RNA in ribonucleoprotein complexes, the method is especially useful for detecting changes in protein-RNA interactions. By probing the E. coli 30S ribosome subunit, we established that the reactivity pattern of lysine residues quantitatively reflects structure models derived from X-ray crystallography. We also used the strategy to assess differences in three conformations of purified human spliceosomes in the context of recent cryo-electron microscopy models. Our results demonstrate that the probing method yields powerful biochemical information that helps contextualize architectural rearrangements of intermediate resolution structures of macromolecular complexes, often solved in multiple conformations.


Assuntos
Lisina/química , Substâncias Macromoleculares/química , Modelos Moleculares , Conformação Molecular , Acetilação , Cristalografia por Raios X , Humanos , Peptídeos/química , RNA/química , Subunidades Ribossômicas Menores de Bactérias/metabolismo , Spliceossomos/metabolismo , Espectrometria de Massas em Tandem
5.
J Org Chem ; 83(9): 5187-5198, 2018 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-29696980

RESUMO

Thailanstatin A has been isolated recently from the fermentation broth of B. thailandensis MSMB43. We describe here an enantioselective convergent synthesis of thailanstatin A methyl ester and evaluation of its splicing activity. Synthesis of both highly functionalized tetrahydropyran rings were carried out from commercially available tri- O-acetyl-d-glucal as the key starting material. Our convergent synthesis involved the synthesis of both tetrahydropyran fragments in a highly stereoselective manner. The fragments were then coupled using cross-metathesis as the key step. The synthesis of the diene subunit included a highly stereoselective Claisen rearrangement, a Cu(I)-mediated conjugate addition of MeLi to set the C-14 methyl stereochemistry, a reductive amination reaction to install the C16-amine functionality, and a Wittig olefination reaction to incorporate the diene unit. The epoxy alcohol subunit was synthesized by a highly selective anomeric allylation, a Peterson olefination, and a vanadium catalyzed epoxidation that installed the epoxide stereoselectively. Cross-metathesis of the olefins provided the methyl ester derivative of thailanstatin A. We have carried out in vitro splicing studies of the methyl ester derivative, which proved to be a potent inhibitor of the spliceosome.


Assuntos
Ésteres/química , Piranos/síntese química , Piranos/farmacologia , Splicing de RNA/efeitos dos fármacos , Técnicas de Química Sintética , Piranos/química , Estereoisomerismo
6.
Int J Syst Evol Microbiol ; 67(12): 5211-5215, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29087276

RESUMO

A novel streptomycete, strain 594T, isolated from Brazilian soil collected under cerrado (savanna) vegetation cover is described. Strain 594T produced thermophilic chitinolytic proteases in assays containing feather meal and corn steep liquor as sole sources of carbon and nitrogen. The strain produced white to grey aerial mycelium and spiral chains of spiny-surfaced spores on the aerial mycelium and did not produce diffusible pigments. The ll-isomer of diaminopimelic acid was present in the cell wall and menaquinones were predominantly MK-9(H6) (52 %) and MK-9(H8) (30 %) with 6 % MK-9(H4) and slightly less than 1 % MK-9(H2). Polar lipids present were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and an unknown phospholipid. The major fatty acids were anteiso-C15 : 0, anteiso-C16 : 0, anteiso-C14 : 0 and anteiso-C17 : 0. The G+C content of the genomic DNA was 70.4 mol%. Phylogenetic analysis of the nearly complete 16S rRNA gene sequence indicated that it differed from described Streptomyces species. Multilocus sequence analysis (MLSA) using five housekeeping genes (atpD, gyrB, rpoB, recA and trpB) comparing Streptomyces type strains showed that the MLSA distance of strain 594T to the most closely related species was greater than the 0.007 threshold. The in silico DNA-DNA relatedness between the genome sequence of strain 594T and that of the phylogenetically nearest species was well below the species level recommendation. There was thus multiple evidence justifying the description of this strain as representing a novel species, for which the name Streptomyces odonnellii sp. nov. is proposed. The type strain is 594T (=IMPPG 594T=DSM 41949T=NRRL B-24891T).


Assuntos
Pradaria , Filogenia , Microbiologia do Solo , Streptomyces/classificação , Técnicas de Tipagem Bacteriana , Composição de Bases , Brasil , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Genes Bacterianos , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Streptomyces/genética , Vitamina K 2/análogos & derivados , Vitamina K 2/química
7.
Phys Rev Lett ; 113(15): 155302, 2014 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-25375719

RESUMO

We measure the dispersion relation, gap, and magnetic moment of a magnon in the ferromagnetic F = 1 spinor Bose-Einstein condensate of (87)Rb. From the dispersion relation we measure an average effective mass 1.033(2)(stat)(10)(sys) times the atomic mass, as determined by interfering standing and running coherent magnon waves within the dense and trapped condensed gas. The measured mass is higher than theoretical predictions of mean-field and beyond-mean-field Beliaev theory for a bulk spinor Bose gas with s-wave contact interactions. We observe a magnon energy gap of h × 2.5(1)(stat)(2)(sys) Hz, which is consistent with the predicted effect of magnetic dipole-dipole interactions. These dipolar interactions may also account for the high magnon mass. The effective magnetic moment of -1.04(2)(stat)(8)(sys) times the atomic magnetic moment is consistent with mean-field theory.

8.
Polymers (Basel) ; 16(6)2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38543466

RESUMO

Conventional methods for pathogen detection in water rely on time-consuming enrichment steps followed by biochemical identification strategies, which require assay times ranging from 24 hours to a week. However, in recent years, significant efforts have been made to develop biosensing technologies enabling rapid and close-to-real-time detection of waterborne pathogens. In previous studies, we developed a plastic optical fiber (POF) immunosensor using an optoelectronic configuration consisting of a U-Shape probe connected to an LED and a photodetector. Bacterial detection was evaluated with the immunosensor immersed in a bacterial suspension in water with a known concentration. Here, we report on the sensitivity of a new optoelectronic configuration consisting of two POF U-shaped probes, one as the reference and the other as the immunosensor, for the detection of Escherichia coli. In addition, another methos of detection was tested where the sensors were calibrated in the air, before being immersed in a bacterial suspension and then read in the air. This modification improved sensor sensitivity and resulted in a faster detection time. After the immunocapture, the sensors were DAPI-stained and submitted to confocal microscopy. The histograms obtained confirmed that the responses of the immunosensors were due to the bacteria. This new sensor detected the presence of E. coli at 104 CFU/mL in less than 20 min. Currently, sub-20 min is faster than previous studies using fiber-optic based biosensors. We report on an inexpensive and faster detection technology when compared with conventional methods.

9.
Sci Rep ; 14(1): 21518, 2024 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-39277613

RESUMO

Advances in omics technologies have enabled the in-depth study of microbial communities and their metabolic profiles from all environments. Here metagenomes were sampled from piranha (Serrasalmus rhombeus) and from river water from the Rio São Benedito (Amazon Basin). Shotgun metagenome sequencing was used to explore diversity and to test whether fish microbiomes are a good proxy for river microbiome studies. The results showed that the fish microbiomes were not significantly different from the river water microbiomes at higher taxonomic ranks. However, at the genus level, fish microbiome alpha diversity decreased, and beta diversity increased. This result repeated for functional gene abundances associated with specific metabolic categories (SEED level 3). A clear delineation between water and fish was seen for beta diversity. The piranha microbiome provides a good and representative subset of its river water microbiome. Variations seen in beta biodiversity were expected and can be explained by temporal variations in the fish microbiome in response to stronger selective forces on its biodiversity. Metagenome assembled genomes construction was better from the fish samples. This study has revealed that the microbiome of a piranha tells us a lot about its river water microbiome and function.


Assuntos
Biodiversidade , Microbioma Gastrointestinal , Rios , Rios/microbiologia , Microbioma Gastrointestinal/genética , Animais , Metagenoma , Metagenômica/métodos , Microbiologia da Água , Bactérias/genética , Bactérias/classificação , Bactérias/isolamento & purificação
10.
Antonie Van Leeuwenhoek ; 103(3): 635-46, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23142860

RESUMO

The draft genome of the soil actinomycete Dietzia cinnamea P4 reveals a versatile group of α/ß-hydrolase fold enzymes. Phylogenetic and comparative sequence analyses were used to classify the α/ß-hydrolases of strain P4 into six different groups: (i) lipases, (ii) esterases, (iii) epoxide hydrolases, (iv) haloacid dehalogenases, (v) C-C breaking enzymes and (vi) serine peptidases. The high number of lipases/esterases (41) and epoxide hydrolase enzymes (14) present in the relatively small (3.6 Mb) P4 genome is unusual; it is likely to be linked to the survival of strain P4 in its natural environment. Strain P4 is thus equipped with a large number of genes which would appear to confer survivability in harsh hot tropical soil. As such, this highly resilient soil bacterial strain provides an interesting genome for enzyme mining for applications in the field of biotransformations of polymeric compounds.


Assuntos
Actinomycetales/enzimologia , Bacillus anthracis/genética , Biotecnologia/métodos , DNA Bacteriano/química , DNA Bacteriano/genética , Hidrolases/metabolismo , Actinomycetales/genética , Bacillus anthracis/isolamento & purificação , Genoma Bacteriano , Hidrolases/classificação , Hidrolases/genética , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos
11.
Plants (Basel) ; 12(9)2023 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-37176954

RESUMO

Improvements in agricultural productivity are required to meet the demand of a growing world population. Phytopathogens, weeds, and insects are challenges to agricultural production. The toxicity and widespread application of persistent synthetic pesticides poses a major threat to human and ecosystem health. Therefore, sustainable strategies to control pests are essential for agricultural systems to enhance productivity within a green paradigm. Allelochemicals are a less persistent, safer, and friendly alternative to efficient pest management, as they tend to be less toxic to non-target organisms and more easily degradable. Microalgae produce a great variety of allelopathic substances whose biocontrol potential against weeds, insects, and phytopathogenic fungi and bacteria has received much attention. This review provides up-to-date information and a critical perspective on allelochemicals from microalgae and their potential as biopesticides.

12.
Sci Total Environ ; 902: 166091, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37553055

RESUMO

The symbiotic relationships between crop species and arbuscular mycorrhizal fungi (AMF) are crucial for plant health, productivity, and environmental sustainability. The roles of AMF in reducing crop stress caused by cadmium (Cd) toxicity and in the remediation of Cd-contaminated soil are not fully understood. Here we report on a meta-analysis that sought to identify the functions of AMF in cereals under Cd stress. A total of 54 articles published between January 1992 and September 2022 were used to create the dataset, which provided 7216 data sets on mycorrhizal cereals under Cd stress examined. AMF effects on colonization rate, biomass, physiological level, nutritional level, and plant Cd level were measured using the logarithmic response ratio (Ln R). The results showed that AMF overall greatly reduced 5.14 - 33.6 % Cd stress on cereals in greenhouse experiments under controlled conditions. AMF colonization significantly stimulated crop biomass by 65.7 %, boosted the formation of photosynthetic pigments (23.2 %), and greatly increased plant nitrogen (24.8 %) and phosphorus (58.4 %) uptake. The dilution effect of mycorrhizal plants made the Cd concentration decline by 25.2 % in AMF plants compared to non-mycorrhizal ones. AMF also alleviated Cd stress by improving osmotic regulators (soluble protein, sugar, and total proline, from 14.8 to 36.0 %) and lowering the membrane lipid peroxidation product (MDA, 12.9 %). Importantly, the results from the random forest and model selection analysis demonstrated that crop type, soil characteristics, chemical form, and Cd levels were the main factors determining the function of AMF in alleviating Cd stress. Additionally, there was a significant interaction between AMF colonization rate and Cd addition, but their interactive effect was less than the colonization rate alone. This meta-analysis demonstrated that AMF inoculation could be considered as a promising strategy for mitigation of Cd stress in cereals.


Assuntos
Micorrizas , Micorrizas/fisiologia , Cádmio/análise , Grão Comestível/química , Simbiose , Solo , Raízes de Plantas/microbiologia
13.
Braz J Microbiol ; 43(4): 1242-54, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24031949

RESUMO

The importance and protection of mangrove ecosystems has been recognized in Brazilian Federal law since 1965. Being protected in law, however, has not always guaranteed their protection in practice. Mangroves are found in coastal and estuarine locations, which are prime real estate for the growth of cities, ports and other economic activities important for Brazilian development. In this mini-review we introduce what mangroves are and why they are so important. We give a brief overview of the microbial diversity found in mangrove sediments and then focus on diversity studies from Brazilian mangroves. We highlight the breadth and depth of knowledge about mangrove microbial communities gained from studying Brazilian mangroves. We report on the exciting findings of molecular microbial ecology methods that have been very successfully applied to study bacterial communities. We note that there have been fewer studies that focus on fungal communities and that fungal diversity studies deserve more attention. The review ends with a look at how a combination of new molecular biology methods and isolation studies are being developed to monitor and conserve mangrove ecosystems and their associated microbial communities. These recent studies are having a global impact and we hope they will help to protect and re-establish mangrove ecosystems.

14.
Microorganisms ; 11(1)2022 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-36677325

RESUMO

Microalgae are regarded as a promising source of biodiesel. In contrast with conventional crops currently used to produce commercial biodiesel, microalgae can be cultivated on non-arable land, besides having a higher growth rate and productivity. However, microalgal biodiesel is not yet regarded as economically competitive, compared to fossil fuels and crop-based biodiesel; therefore, it is not commercially produced. This review provides an overall perspective on technologies with the potential to increase efficiency and reduce the general costs of biodiesel production from microalgae. Opportunities and challenges for large-scale production are discussed. We present the current scenario of Brazilian research in the field and show a successful case in the research and development of microalgal biodiesel in open ponds by Petrobras. This publicly held Brazilian corporation has been investing in research in this sector for over a decade.

15.
Microbiol Resour Announc ; 11(4): e0110521, 2022 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-35343769

RESUMO

Brucella intermedia/Ochrobactrum intermedium strain DF13 was isolated from Brazilian soil and is able to degrade 2,4-dichlorophenoxyacetic acid (2,4-D). Here, we report on its genome sequence, with 4,570,268 bp and a 57.8% G+C content.

16.
Microbiol Resour Announc ; 11(3): e0110421, 2022 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-35225675

RESUMO

Enterobacter hormaechei strain MG02 was isolated from a mixed culture collected from soil with a history of pesticide application. This strain degrades 2,4-dichlorophenoxyacetic acid (2,4-D). Here, we report on its genome, which has 4,923,875 bp and 55.4% G+C content.

17.
Plants (Basel) ; 11(22)2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36432833

RESUMO

Soil available phosphorus (P) is one of the main factors limiting plant growth and yield. This study aimed to determine the role of arbuscular mycorrhizal fungi (AMF) in P-use efficiency in two maize genotypes with contrasting root systems in response to low P stress. Maize genotypes small-rooted Shengrui 999 and large-rooted Zhongke 11 were grown in rhizoboxes that were inoculated with or without AMF (Funneliformis mosseae) under low P (no added P) or optimal P (200 mg kg-1) for 53 days. Low P stress significantly inhibited shoot and root growth, photosynthesis, tissue P content, and root P concentration in both genotypes. Shengrui 999 was more tolerant to P stress with less reduction of these traits compared to Zhongke 11. Shengrui 999 had a higher AMF infection rate than Zhongke 11 at both P levels. Under P deficit, inoculation with AMF significantly promoted plant growth and P uptake in both genotypes with more profound effects seen in Zhongke 11, whilst Shengrui 999 was more dependent on AMF under optimal P. Low P stress inhibited the growth and physiological attributes of both genotypes. The small-rooted Shengrui 999 was more tolerant to low P than Zhongke 11. Inoculation with AMF alleviates low P stress in both genotypes with a more profound effect on Zhongke 11 at low P and on Shengrui 999 at high P conditions.

18.
Life (Basel) ; 12(10)2022 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-36294926

RESUMO

Multidrug-resistant bacteria are of critical importance and a problem for human health and food preservation; the discovery of new antimicrobial substances to control their proliferation is part of the solution. This work reports on 57 antagonistic Aeromonas strains, of which 38 strains were antagonistic towards problematic human pathogens. The genome of the most antagonistic strain was sequenced and identified as Aeromonas allosaccharophila. Its genome was fully annotated and mined for genes that might explain that activity. Strain AE59-TE was antagonistic toward clinically relevant gram-negative and gram-positive multidrug-resistant bacteria, including Klebsiella pneumoniae KPC, Escherichia coli ESBL, Salmonella typhimurium, and Staphylococcus aureus MRSA. Strain AE59-TE2 was identified by multilocus sequence analysis. Genome mining identified four genes homologous to the bacteriocin, zoocin A from Streptococcus equi and a gene 98% similar to cvpA linked to colicin V production. A. allosaccharophila strain AE59-TE2 produced antimicrobial activity against a broad range of bacteria, including important gram-negative bacteria, not typically targeted by bacteriocins. Herewere described novel zoocin genes that are promising for industrial applications in the food and health sectors. Interesting and important antagonistic activity is described combined with the first detailed genomic analysis of the species Aeromonas allosaccharophila.

19.
Antonie Van Leeuwenhoek ; 100(3): 341-7, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21614495

RESUMO

A novel yeast species within the Metschnikowiaceae is described based on a strain from the sugarcane (Saccharum sp.) rhizoplane of an organically managed farm in Rio de Janeiro, Brazil. The D1/D2 domain of the large subunit ribosomal RNA gene sequence analysis showed that the closest related species were Candida tsuchiyae with 86.2% and Candida thailandica with 86.7% of sequence identity. All three are anamorphs in the Clavispora opuntiae clade. The name Candida middelhoveniana sp. nov. is proposed to accommodate this highly divergent organism with the type strain Instituto de Microbiologia, Universidade Federal do Rio de Janeiro (IMUFRJ) 51965(T) (=Centraalbureau voor Schimmelcultures (CBS) 12306(T), Universidade Federal de Minas Gerais (UFMG)-70(T), DBVPG 8031(T)) and the GenBank/EMBL/DDBJ accession number for the D1/D2 domain LSU rDNA sequence is FN428871. The Mycobank deposit number is MB 519801.


Assuntos
Candida/classificação , Candida/isolamento & purificação , Saccharum/microbiologia , Microbiologia do Solo , Brasil , Candida/genética , DNA Fúngico/genética , DNA Ribossômico/genética , Dados de Sequência Molecular , Agricultura Orgânica , Filogenia , Saccharum/crescimento & desenvolvimento
20.
Braz J Microbiol ; 52(2): 727-738, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33694059

RESUMO

Azo dyes are widely used in the textile industry due to their resistance to light, moisture, and oxidants. They are also an important class of environmental contaminant because of the amount of dye that reaches natural water resources and because they can be toxic, mutagenic, and carcinogenic. Different technologies are used for the decolorization of wastewater containing dyes; among them, the biological processes are the most promising environmentally. The aim of this study was to evaluate the potential of Phanerochaete chrysosporium strain ME-446 to safely decolorize three azo dyes: Direct Yellow 27 (DY27), Reactive Black 5 (RB5), and Reactive Red 120 (RR120). Decolorization efficiency was determined by ultraviolet-visible spectrophotometry and the phytotoxicity of the solutions before and after the fungal treatment was analyzed using Lactuca sativa seeds. P. chrysosporium ME-446 was highly efficient in decolorizing DY27, RB5, and RR120 at 50 mg L-1, decreasing their colors by 82%, 89%, and 94% within 10 days. Removal of dyes was achieved through adsorption on the fungal mycelium as well as biodegradation, inferred by the changes in the dyes' spectral peaks. The intensive decolorization of DY27 and RB5 corresponded to a decrease in phytotoxicity. However, phytotoxicity increased during the removal of color for the dye RR120. The ecotoxicity tests showed that the absence of color does not necessarily translate to an absence of toxicity.


Assuntos
Compostos Azo/metabolismo , Phanerochaete/metabolismo , Poluentes Químicos da Água/metabolismo , Compostos Azo/toxicidade , Biodegradação Ambiental , Fermentação , Lactuca/efeitos dos fármacos , Lactuca/crescimento & desenvolvimento , Micélio/metabolismo , Naftalenos/metabolismo , Naftalenos/toxicidade , Naftalenossulfonatos/metabolismo , Naftalenossulfonatos/toxicidade , Águas Residuárias/química , Águas Residuárias/microbiologia , Poluentes Químicos da Água/toxicidade
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa