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1.
Analyst ; 144(13): 4051-4059, 2019 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-31157328

RESUMO

Rapid, simultaneous, and sensitive quantification of multiplex prostate biomarkers plays an important role in early diagnosis, especially for obese men and patients. Herein, a surface-enhanced Raman scattering (SERS)-based vertical flow assay (VFA) is presented for simultaneous detection of multiplex prostate cancer biomarkers, such as prostate-specific antigen (PSA), carcinoembryonic antigen (CEA), and alpha-fetoprotein (AFP) on a single test spot. In practice, Raman dyes (RDs) encoded core-shell SERS nanotags instead of conventional gold colloids used in the colorimetric assay are employed in the sensing membrane of SERS based VFAs for multiplex protein detection. Because of the enhanced Raman signal of the core-shell nanostructure and the high surface area to volume ratio (SVR) of the porous sensing membrane, this proposed biosensor shows a wide linear dynamic range (LDR) with detection limits of 0.37, 0.43, and 0.26 pg mL-1 for PSA, CEA, and AFP, respectively, suggesting that this approach can be a good candidate in point of care testing (POCT) for rapid and sensitive biomarker detection and has a huge potential in multiplex analysis and cancer diagnosis.


Assuntos
Biomarcadores Tumorais/sangue , Técnicas Biossensoriais/métodos , Antígeno Carcinoembrionário/sangue , Calicreínas/sangue , Nanopartículas Metálicas/química , Antígeno Prostático Específico/sangue , alfa-Fetoproteínas/análise , Animais , Anticorpos/imunologia , Biomarcadores Tumorais/imunologia , Antígeno Carcinoembrionário/imunologia , Colódio/química , Corantes/química , Cabras , Ouro/química , Humanos , Imunoensaio/métodos , Calicreínas/imunologia , Limite de Detecção , Masculino , Oxazinas/química , Porosidade , Antígeno Prostático Específico/imunologia , Neoplasias da Próstata/sangue , Prata/química , Análise Espectral Raman/métodos , Compostos de Sulfidrila/química , alfa-Fetoproteínas/imunologia
2.
Carbohydr Polym ; 220: 22-29, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31196544

RESUMO

The control of chitosan/silver nanoparticle composite microsphere (CAgMs) size is crucial for tuning its function. In the current work, monodisperse organically-modified CAgMs with controllable size were synthesized using a two-step method. The fine-tuning of the microsphere size was confirmed by many reaction parameters while the cross-linking agent was the key research object. Through physical and thermodynamic analysis, we found the cross-linking agent-induced smaller size, higher silver concentration, more heightened glass transition temperature and stronger hydrogen bond network. The as-prepared microspheres exhibited strong bacteriostasis and fresh-keeping function depending on cross-linking agent concentration. The phenomenon is believed to be derived from the difference in microorganism adsorption and killing ability from induced varying specific surface area and encapsulated silver content. Our current work highlights the size-controllable preparation of CAgMs, and based on our findings, small size CAgMs can be a promising candidate in the field of antibacterial and fruit preservation applications.


Assuntos
Antibacterianos/farmacologia , Quitosana/toxicidade , Conservação de Alimentos/métodos , Malpighiaceae/microbiologia , Nanopartículas Metálicas/toxicidade , Microesferas , Prata/toxicidade , Quitosana/química , Escherichia coli/efeitos dos fármacos , Nanopartículas Metálicas/química , Tamanho da Partícula , Penicillium/efeitos dos fármacos , Saccharomyces cerevisiae/efeitos dos fármacos
3.
Biomed Res Int ; 2019: 8329306, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31080830

RESUMO

Background: Inconsistent data have been reported for the effectiveness of intramuscular botulinum toxin type A (BTXA) in patients with limb spasticity after stroke. This meta-analysis of available randomized controlled trials (RCTs) aimed to determine the efficacy and safety of BTXA in adult patients with upper and lower limb spasticity after stroke. Methods: An electronic search was performed to select eligible RCTs in PubMed, Embase, and the Cochrane library through December 2018. Summary standard mean differences (SMDs) and relative risk (RR) values with corresponding 95% confidence intervals (CIs) were employed to assess effectiveness and safety outcomes, respectively. Results: Twenty-seven RCTs involving a total of 2,793 patients met the inclusion criteria, including 16 and 9 trials assessing upper and lower limb spasticity cases, respectively. For upper limb spasticity, BTXA therapy significantly improved the levels of muscle tone (SMD=-0.76; 95% CI -0.97 to -0.55; P<0.001), physician global assessment (SMD=0.51; 95% CI 0.35-0.67; P<0.001), and disability assessment scale (SMD=-0.30; 95% CI -0.40 to -0.20; P<0.001), with no significant effects on active upper limb function (SMD=0.49; 95% CI -0.08 to 1.07; P=0.093) and adverse events (RR=1.18; 95% CI 0.72-1.93; P=0.509). For lower limb spasticity, BTXA therapy was associated with higher Fugl-Meyer score (SMD=5.09; 95%CI 2.16-8.01; P=0.001), but had no significant effects on muscle tone (SMD=-0.12; 95% CI -0.83 to 0.59; P=0.736), gait speed (SMD=0.06; 95% CI -0.02 to 0.15; P=0.116), and adverse events (RR=1.01; 95% CI 0.71-1.45; P=0.949). Conclusions: BTXA improves muscle tone, physician global assessment, and disability assessment scale in upper limb spasticity and increases the Fugl-Meyer score in lower limb spasticity.


Assuntos
Toxinas Botulínicas Tipo A/efeitos adversos , Toxinas Botulínicas Tipo A/uso terapêutico , Extremidades/fisiopatologia , Espasticidade Muscular/tratamento farmacológico , Espasticidade Muscular/etiologia , Acidente Vascular Cerebral/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Espasticidade Muscular/fisiopatologia , Tono Muscular/efeitos dos fármacos , Tono Muscular/fisiologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Acidente Vascular Cerebral/fisiopatologia , Resultado do Tratamento
4.
Sensors (Basel) ; 18(6)2018 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-29882796

RESUMO

Corn stalk lodging is caused by different factors, including severe wind storms, stalk cannibalization, and stalk rots, and it leads to yield loss. Determining how to rapidly evaluate corn lodging resistance will assist scientists in the field of crop breeding to understand the contributing factors in managing the moisture, chemical fertilizer, and weather conditions for corn growing. This study proposes a non-destructive and direction-insensitive method, using a strain sensor and two single axis angle sensors to measure the corn stalk lodging resistance in the field. An equivalent force whose direction is perpendicular to the stalk is utilized to evaluate the corn lodging properties when a pull force is applied on the corn stalk. A novel measurement device is designed to obtain the equivalent force with the coefficient of variation (CV) of 4.85%. Five corn varieties with two different planting densities are arranged to conduct the experiment using the novel measurement device. The experimental results show that the maximum equivalent force could reach up to 44 N. A strong relationship with the square of the correlation coefficient of 0.88 was obtained between the maximum equivalent forces and the corn field’s stalk lodging rates. Moreover, the stalk lodging angles corresponding to the different pull forces over a measurement time of 20 s shift monotonically along the equivalent forces. Thus, the non-destructive and direction-insensitive method is an excellent tool for rapid analysis of stalk lodging resistance in corn, providing critical information on in-situ lodging dynamics.

5.
ACS Nano ; 11(8): 8199-8206, 2017 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-28654269

RESUMO

We introduce a simplified and modular architecture for design and construction of complex origami nanostructures. A series of basic two-dimensional and three-dimensional structures are presented. As the resulting structures can be virtually divided into blocks, modular remodeling such as translocation, contraction/extension, and bending is carried out. Structures under such a designing framework are morphable. Local conformational changes can propagate to the entire structure to reshape the global conformation.

6.
Sensors (Basel) ; 16(11)2016 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-27827923

RESUMO

The purpose of this study was to develop a portable surface plasmon resonance (SPR) bioanalyzer for the sensitive detection of Escherichia coli O157:H7 in comparison with an enzyme-linked immunosorbent assay (ELISA). The experimental setup mainly consisted of an integrated biosensor and a homemade microfluidic cell with a three-way solenoid valve. In order to detect Escherichia coli O157:H7 using the SPR immunoassay, 3-mercaptopropionic acid (3-MPA) was chemisorbed onto a gold surface via covalent bond for the immobilization of biological species. 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) were used as crosslinker reagents to enable the reaction between 3-MPA and Escherichia coli O157:H7 antibodies by covalent -CO-NH- amide bonding. The experimental results were obtained from the Escherichia coli O157:H7 positive samples prepared by 10-, 20-, 40-, 80-, and 160-fold dilution respectively, which show that a good linear relationship with the correlation coefficient R of 0.982 existed between the response units from the portable SPR bioanalyzer and the concentration of Escherichia coli O157:H7 positive samples. Moreover, the theoretical detection limit of 1.87 × 10³ cfu/mL was calculated from the positive control samples. Compared with the Escherichia coli O157:H7 ELISA kit, the sensitivity of this portable SPR bioanalyzer is four orders of magnitude higher than the ELISA kit. The results demonstrate that the portable SPR bioanalyzer could provide an alternative method for the quantitative and sensitive determination of Escherichia coli O157:H7 in field.


Assuntos
Técnicas Biossensoriais/métodos , Ressonância de Plasmônio de Superfície/métodos , Ensaio de Imunoadsorção Enzimática , Escherichia coli O157/fisiologia , Imunoensaio/métodos , Succinimidas
7.
Appl Opt ; 55(19): 5273-9, 2016 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-27409221

RESUMO

Laser-induced fluorescence is an important technique to study photosynthesis and plants. Information on chlorophyll and other pigments can be obtained. We have been using a mobile laboratory in a Chinese experimental farm setting to study maize (Zea mays L.) leaves by reflectance and fluorescence measurements and correlated the spectroscopic signals to the amount of fertilizer supplied. Further, we studied five different species of maize using the remote monitoring of the fluorescence signatures obtained with the same mobile laboratory, but now in a laser radar remote-sensing configuration. The system separation from the target area was 50 m, and 355 nm pulsed excitation using the frequency-tripled output from an Nd:YAG laser was employed. Principal component analysis and linear discriminant analysis were combined to identify the different maize species using their fluorescence spectra. Likewise, the spectral signatures in reflectance and fluorescence frequently allowed us to separate different fertilizer levels applied to plants of the same species.

8.
Sensors (Basel) ; 16(4)2016 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-27070614

RESUMO

Ethylene as an indicator for evaluating fruit ripening can be measured by very sensitive electrochemical gas sensors based on a high-resolution current produced by a bias potential applied to the electrodes. For this purpose, a measurement system for monitoring ethylene gas concentrations to evaluate fruit ripening by using the electrochemical ethylene sensor was successfully developed. Before the electrochemical ethylene sensor was used to measure the ethylene gas concentrations released from fruits, a calibration curve was established by the standard ethylene gases at concentrations of 2.99 ppm, 4.99 ppm, 8.01 ppm and 10 ppm, respectively, with a flow rate of 0.4 L·min(-1). From the calibration curve, the linear relationship between the responses and concentrations of ethylene gas was obtained in the range of 0-10 ppm with the correlation coefficient R² of 0.9976. The micropump and a novel signal conditioning circuit were implemented in this measurement, resulting in a rapid response in detecting ethylene concentrations down to 0.1 ppm in air and in under 50 s. In this experiment, three kinds of fruits-apples, pears and kiwifruits-were studied at a low concentration (under 0.8 ppm) of trace ethylene content in the air exhaled by fruits. The experimental results showed that a low cost, compact measurement system constructed by using an electrochemical ethylene sensor has a high sensitivity of 0.3907 V·ppm(-1) with a theoretical detection limit of 0.413 ppm, and is non-invasive and highly portable.


Assuntos
Técnicas Biossensoriais/instrumentação , Etilenos/isolamento & purificação , Frutas/crescimento & desenvolvimento , Gases/isolamento & purificação , Técnicas Eletroquímicas , Etilenos/metabolismo , Frutas/química , Frutas/metabolismo , Gases/metabolismo , Limite de Detecção
9.
Sensors (Basel) ; 15(8): 20511-23, 2015 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-26295398

RESUMO

The aim of this study was to develop a circuit for an inexpensive portable biosensing system based on surface plasmon resonance spectroscopy. This portable biosensing system designed for field use is characterized by a special structure which consists of a microfluidic cell incorporating a right angle prism functionalized with a biomolecular identification membrane, a laser line generator and a data acquisition circuit board. The data structure, data memory capacity and a line charge-coupled device (CCD) array with a driving circuit for collecting the photoelectric signals are intensively focused on and the high performance analog-to-digital (A/D) converter is comprehensively evaluated. The interface circuit and the photoelectric signal amplifier circuit are first studied to obtain the weak signals from the line CCD array in this experiment. Quantitative measurements for validating the sensitivity of the biosensing system were implemented using ethanol solutions of various concentrations indicated by volume fractions of 5%, 8%, 15%, 20%, 25%, and 30%, respectively, without a biomembrane immobilized on the surface of the SPR sensor. The experiments demonstrated that it is possible to detect a change in the refractive index of an ethanol solution with a sensitivity of 4.99838 × 10(5) ΔRU/RI in terms of the changes in delta response unit with refractive index using this SPR biosensing system, whereby the theoretical limit of detection of 3.3537 × 10(-5) refractive index unit (RIU) and a high linearity at the correlation coefficient of 0.98065. The results obtained from a series of tests confirmed the practicality of this cost-effective portable SPR biosensing system.


Assuntos
Eletrônica , Ressonância de Plasmônio de Superfície/instrumentação , Conversão Análogo-Digital , Calibragem , Desenho de Equipamento , Etanol/análise , Processamento de Sinais Assistido por Computador , Soluções , Fatores de Tempo
10.
PLoS One ; 10(7): e0132098, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26147997

RESUMO

Kinetic analysis of biomolecular interactions are powerfully used to quantify the binding kinetic constants for the determination of a complex formed or dissociated within a given time span. Surface plasmon resonance biosensors provide an essential approach in the analysis of the biomolecular interactions including the interaction process of antigen-antibody and receptors-ligand. The binding affinity of the antibody to the antigen (or the receptor to the ligand) reflects the biological activities of the control antibodies (or receptors) and the corresponding immune signal responses in the pathologic process. Moreover, both the association rate and dissociation rate of the receptor to ligand are the substantial parameters for the study of signal transmission between cells. A number of experimental data may lead to complicated real-time curves that do not fit well to the kinetic model. This paper presented an analysis approach of biomolecular interactions established by utilizing the Marquardt algorithm. This algorithm was intensively considered to implement in the homemade bioanalyzer to perform the nonlinear curve-fitting of the association and disassociation process of the receptor to ligand. Compared with the results from the Newton iteration algorithm, it shows that the Marquardt algorithm does not only reduce the dependence of the initial value to avoid the divergence but also can greatly reduce the iterative regression times. The association and dissociation rate constants, ka, kd and the affinity parameters for the biomolecular interaction, KA, KD, were experimentally obtained 6.969×10(5) mL·g(-1)·s(-1), 0.00073 s(-1), 9.5466×10(8) mL·g(-1) and 1.0475×10(-9) g·mL(-1), respectively from the injection of the HBsAg solution with the concentration of 16 ng·mL(-1). The kinetic constants were evaluated distinctly by using the obtained data from the curve-fitting results.


Assuntos
Algoritmos , Modelos Químicos , Ressonância de Plasmônio de Superfície
11.
PLoS One ; 10(3): e0122005, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25799327

RESUMO

A surface plasmon resonance (SPR) immunoassay with an immobilization of self-assembled molecular identification membrane for the detection of residual Clenbuterol Hydrochloride (CLB) in pork liver was systematically investigated and experimentally validated for its high performance. SPR immunoassay with a regular competitive inhibition assay cannot be directly verified to detect CLB residuals. In this study, the binding of Au film with mercaptopropionic acid was investigated using the known form of the strong S-Au covalent bonds formed by the chemical radical of the mercaptopropionic acid and the Au film. After that, the immunoglobulin IgG of swine (SwIgG-CLB) was bonded with the mercaptopropionic acid by covalent -CO-NH- amide bonding. The modified comprehensive analysis of how the membrane structure works was introduced together with the customized SPR bioanalyzer. In order to evaluate the performance of this biomembrane structure, the concentrations of CLB-contained solutions of 0 ng · mL(-1), 10 ng · mL(-1), 20 ng · mL(-1), 33.3 ng · mL(-1), and 40 ng · mL(-1) were prepared by adding CLB reagents into the solutions of CLB antibody (Clenbuterol Hydrochloride Antibody, CLB-Ab), successively and then the response unit (RU) was measured individually. Using the data collected from the linear CCD array, the fitting curve was established with the R-Square value of 0.9929. Correspondingly, the recovery rate ranged from 88.48% to 103.21% was experimented and the limit of detection of CLB in 1.26 ng · mL(-1) was obtained efficiently. It was concluded that the detection method associated with biomembrane properties is expected to contribute much to the determination of residual CLB in pork liver quantitatively by using the customized SPR bioanalyzer.


Assuntos
Técnicas Biossensoriais , Clembuterol , Fígado , Ressonância de Plasmônio de Superfície/métodos , Animais , Ressonância de Plasmônio de Superfície/instrumentação , Suínos
12.
Environ Microbiol ; 13(11): 3059-74, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21951343

RESUMO

Submerged metal surfaces in marine waters undergo rapid microbial colonization and biocorrosion, causing huge damage to marine engineering facilities and significant financial losses. In coastal areas, an accelerated and particularly severe form of biocorrosion termed accelerated low water corrosion (ALWC) is widespread globally. While identification of biocorroding microorganisms and the dynamics of their community structures is the key for understanding the processes and mechanisms leading to ALWC, neither one is presently understood. In this study, analysis of constructed clone libraries and qPCR assays targeting group-specific 16S rRNA or functional marker genes were used to determine the identity and abundance of putative early carbon steel surface-colonizing and biocorroding microbes in coastal seawater. Diverse microbial groups including 10 bacterial phyla, archaea and algae were found to putatively participate in the surface-colonizing process. Analysis of the community structure of carbon steel surface microbiota revealed a temporal succession leading to ALWC. By extending the current state of knowledge, our work demonstrates the global importance of Alphaproteobacteria (mainly Rhodobacterales), Gammaproteobacteria (mainly Alteromonadales and Oceanospirillales), Bacteroidetes (mainly Flavobacteriales) and microalgae as the pioneer and sustaining surface colonizers that contribute to initial formation and development of surface biofilms. We also discovered Epsilonproteobacteria and the recently described Zetaproteobacteria as putative corrosion-causing microorganisms during early steps of the ALWC process. Hence, our study reports that Zetaproteobacteria may be ubiquitous also in non-hydrothermal coastal seawaters and that ALWC of submerged carbon steel surfaces in coastal waters may involve a highly diverse, complex and dynamic microbial consortium. Our finding that Epsilon- and Zetaproteobacteria may play pivotal roles in ALWC provides a new starting point for future investigation of the ALWC process and mechanism in marine environments. Further studies of Epsilon- and Zetaproteobacteria in particular may thus help with the design of effective corrosion prevention and control strategies.


Assuntos
Bacteroidetes/genética , Biofilmes , Metagenoma , Proteobactérias/genética , Água do Mar/microbiologia , Aço , Bacteroidetes/classificação , Corrosão , Biblioteca Gênica , Dados de Sequência Molecular , Oceano Pacífico , Filogenia , Proteobactérias/classificação , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Microbiologia da Água
13.
Appl Environ Microbiol ; 76(21): 7036-47, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20833786

RESUMO

Bacterial anaerobic ammonium oxidation (anammox) is an important process in the marine nitrogen cycle. Because ongoing eutrophication of coastal bays contributes significantly to the formation of low-oxygen zones, monitoring of the anammox bacterial community offers a unique opportunity for assessment of anthropogenic perturbations in these environments. The current study used targeting of 16S rRNA and hzo genes to characterize the composition and structure of the anammox bacterial community in the sediments of the eutrophic Jiaozhou Bay, thereby unraveling their diversity, abundance, and distribution. Abundance and distribution of hzo genes revealed a greater taxonomic diversity in Jiaozhou Bay, including several novel clades of anammox bacteria. In contrast, the targeting of 16S rRNA genes verified the presence of only "Candidatus Scalindua," albeit with a high microdiversity. The genus "Ca. Scalindua" comprised the apparent majority of active sediment anammox bacteria. Multivariate statistical analyses indicated a heterogeneous distribution of the anammox bacterial assemblages in Jiaozhou Bay. Of all environmental parameters investigated, sediment organic C/organic N (OrgC/OrgN), nitrite concentration, and sediment median grain size were found to impact the composition, structure, and distribution of the sediment anammox bacterial community. Analysis of Pearson correlations between environmental factors and abundance of 16S rRNA and hzo genes as determined by fluorescent real-time PCR suggests that the local nitrite concentration is the key regulator of the abundance of anammox bacteria in Jiaozhou Bay sediments.


Assuntos
Bactérias Anaeróbias/metabolismo , Sedimentos Geológicos/microbiologia , Compostos de Amônio Quaternário/metabolismo , Microbiologia da Água , Bactérias Anaeróbias/genética , Bactérias Anaeróbias/isolamento & purificação , China , DNA Bacteriano/genética , Meio Ambiente , Eutrofização , Genes Bacterianos/genética , Dados de Sequência Molecular , Oceanos e Mares , Oxirredução , Filogenia , RNA Ribossômico 16S/genética
14.
Appl Environ Microbiol ; 76(14): 4691-702, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20511433

RESUMO

Ongoing anthropogenic eutrophication of Jiaozhou Bay offers an opportunity to study the influence of human activity on bacterial communities that drive biogeochemical cycling. Nitrification in coastal waters appears to be a sensitive indicator of environmental change, suggesting that function and structure of the microbial nitrifying community may be associated closely with environmental conditions. In the current study, the amoA gene was used to unravel the relationship between sediment aerobic obligate ammonia-oxidizing Betaproteobacteria (Beta-AOB) and their environment in Jiaozhou Bay. Protein sequences deduced from amoA gene sequences grouped within four distinct clusters in the Nitrosomonas lineage, including a putative new cluster. In addition, AmoA sequences belonging to three newly defined clusters in the Nitrosospira lineage were also identified. Multivariate statistical analyses indicated that the studied Beta-AOB community structures correlated with environmental parameters, of which nitrite-N and sediment sand content had significant impact on the composition, structure, and distribution of the Beta-AOB community. Both amoA clone library and quantitative PCR (qPCR) analyses indicated that continental input from the nearby wastewater treatment plants and polluted rivers may have significant impact on the composition and abundance of the sediment Beta-AOB assemblages in Jiaozhou Bay. Our work is the first report of a direct link between a sedimentological parameter and the composition and distribution of the sediment Beta-AOB and indicates the potential for using the Beta-AOB community composition in general and individual isolates or environmental clones in the Nitrosomonas oligotropha lineage in particular as bioindicators and biotracers of pollution or freshwater or wastewater input in coastal environments.


Assuntos
Amônia/metabolismo , Biodiversidade , Sedimentos Geológicos/microbiologia , Metagenoma , Nitrosomonadaceae/classificação , Nitrosomonadaceae/metabolismo , Proteínas de Bactérias/genética , China , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Eutrofização , Dados de Sequência Molecular , Nitratos/metabolismo , Nitritos/metabolismo , Nitrosomonadaceae/genética , Nitrosomonadaceae/isolamento & purificação , Oxirredução , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
15.
FEMS Microbiol Ecol ; 72(3): 370-85, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20402778

RESUMO

The ecological characteristics of amoA-encoding archaea (AEA) in deep-sea sediments are largely unsolved. This paper aimed to study the diversity, structure, distribution and abundance of the archaeal community and especially its AEA components in the cold seep surface sediments of the Okhotsk Sea, a marginal sea harboring one of the largest methane hydrate reservoirs in the world. Diverse archaeal 16S rRNA gene sequences were identified, with the majority being related to sequences from other cold seep and methane-rich sediment environments. However, the AEA diversity and abundance were quite low as revealed by amoA gene analyses. Correlation analysis indicates that the abundance of the archaeal amoA genes was correlated with the sediment organic matter content. Thus, it is possible that the amoA-carrying archaea here might utilize organic matter for a living. The affiliation of certain archaeal amoA sequences to the GenBank sequences originally obtained from deep-sea hydrothermal vent environments indicated that the related AEA either have a wide range of temperature adaptation or they have a thermophilic evolutionary history in the modern cold deep-sea sediments of the Okhotsk Sea. The dominance of ammonia-oxidizing bacteria over AEA may indicate that bacteria play a significant role in nitrification in the Okhotsk Sea cold seep sediments.


Assuntos
Archaea/isolamento & purificação , Biodiversidade , Sedimentos Geológicos/microbiologia , Água do Mar/microbiologia , Microbiologia da Água , Archaea/classificação , Archaea/enzimologia , Archaea/genética , DNA Arqueal/genética , Biblioteca Gênica , Genes Arqueais , Metano , Oxirredutases/genética , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
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