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1.
Bioprocess Biosyst Eng ; 37(10): 2121-9, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24781206

RESUMO

CelTherm is a biochemical process to produce renewable fuels and chemicals from lignocellulosic biomass. The present study's objective was to determine the level of treatment/purity of the microbial triacylglyceride oil (TAG) necessary to facilitate fuel production. After a unique microbe aerobically synthesizes TAG from biomass-derived sugars, the microbes were harvested and dried then crude TAG was chemically extracted from the residual biomass. Some TAGs were further purified to hydrotreating process requirements. Both grades were then noncatalytically cracked into a petroleum-like intermediate characterized by gas chromatography. Experiments were repeated using refined soybean oil for comparison to previous studies. The products from crude microbial TAG cracking were then further refined into a jet fuel product. Fuel tests indicate that this jet fuel corresponds to specifications for JP-8 military turbine fuel. It was thus concluded that the crude microbial TAG is a suitable feedstock with no further purification required, demonstrating CelTherm's commercial potential.


Assuntos
Microbiota , Óleos/isolamento & purificação , Triglicerídeos/isolamento & purificação , Hidrocarbonetos
2.
Microbiol Spectr ; 9(1): e0039221, 2021 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-34431687

RESUMO

Tests to diagnose acute SARS-CoV-2 infection are at the center of controlling the COVID-19 pandemic. Rapid tests benefit from providing quick results but suffer from lower sensitivity, while PCR tests usually take longer to provide more reliable results and can be difficult to scale to meet population needs. We evaluated the diagnostic efficacy of a Molecular Mirror assay (MMA) using nucleic acid extraction and a nucleic acid extraction-free method to determine its ability to identify SARS-CoV-2 in nasal specimens from individuals suspected of having SARS-CoV-2. We compared the MMA using nucleic acid extraction to the emergency use authorization (EUA)-approved TaqPath reverse transcriptase PCR (RT-PCR) assay to determine its performance characteristics. From 412 total specimens (including 115 previous positives and 297 previous negatives), we found that the positive percent agreement (PPA) was 99.1% (confidence interval [CI], 97.4% to 100.0%) and the negative percent agreement (NPA) was 99.3% (95% CI, 98.4% to 100.0%) for SARS-CoV-2 detection. Using the extraction-free method, we analyzed 109 specimens (51 previous positives and 58 previous negatives) and found that the PPA for the more rapid version of the assay was 87.8% (95% CI, 78.5% to 96.9%) and the NPA was 100.0% (95% CI, 100.0%) for virus detection. The extraction method has performance comparable to what is observed in many PCR-based assays. The extraction-free method has lower PPA but has the advantage of being more rapid and having a higher throughput. Our data offer a proof of concept that nuclear magnetic resonance (NMR) detection can be used in SARS-CoV-2 diagnostic testing and may allow for alternative supply chains to increase testing options. IMPORTANCE Accurate diagnostics for SARS-CoV-2 infections have been critical for responding to the COVID-19 pandemic. Both high-sensitivity/specificity PCR-based tests and lower-sensitivity/specificity rapid antigen assays have been the subject of worldwide supply chain limitations as individual facilities and countries have struggled to meet their population testing needs. We evaluated the diagnostic efficacy of a Molecular Mirror assay (MMA), which uses nuclear magnetic resonance to detect the presence of SARS-CoV-2 nucleic acids both with and without full nucleic acid extractions. We found that compared to a U.S. emergency use authorization (EUA) approved assay (TaqPath) that uses reverse transcriptase PCR (RT-PCR), the MMA had high PPA and NPA with full nucleic acid extractions, and acceptable positive percent agreement (PPA) and negative percent agreement (NPA) with an extraction-free protocol. In a landscape marred by supply chain shortages across the world, altered SARS-CoV-2 detection methods such as the MMA can add to testing supplies while providing quality SARS-CoV-2 testing results.


Assuntos
Teste de Ácido Nucleico para COVID-19/métodos , COVID-19/diagnóstico , Ensaios de Triagem em Larga Escala/métodos , SARS-CoV-2/isolamento & purificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Técnicas de Diagnóstico Molecular/métodos , Pandemias , Reação em Cadeia da Polimerase , Sensibilidade e Especificidade , Tecnologia , Adulto Jovem
3.
Biomed J ; 42(3): 187-192, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31466712

RESUMO

BACKGROUND: Vibrio parahaemolyticus is a Gram-negative bacterium widely distributed in marine environments and a well-recognized invertebrate pathogen frequently isolated from seafood. V. parahaemolyticus may also spread into humans, via contaminated, raw, or undercooked seafood, causing gastroenteritis and diarrhea. METHODS: A Nuclear Magnetic Resonance (NMR)-based detection system was used to detect pathogenic levels of this microorganism (105 CFU/ml) with Molecular Mirroring using iron nanoparticles coated with target-specific biomarkers capable of binding to DNA of the target microorganism. The NMR system generates a signal (in milliseconds) by measuring NMR spin-spin relaxation time T2, which correlates with the amount of microorganism DNA. RESULTS: Compared with conventional microbiology techniques such as real-time PCR (qPCR), the NMR biosensor showed similar limits of detection (LOD) at different concentrations (105-108 CFU/ml) using two DNA extraction methods. In addition, the NMR biosensor system can detect a wide range of microorganism DNAs in different matrices within a short period of time. CONCLUSION: NMR biosensor represents a potential tool for diagnostic and quality control to ensure microbial pathogens such as V. parahaemolyticus are not the cause of infection. The "hybrid" technology (NMR and nanoparticle application) opens a new platform for detecting other microbial pathogens that have impacted human health, animal health and food safety.


Assuntos
Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Reação em Cadeia da Polimerase , Vibrio parahaemolyticus/patogenicidade , Animais , Técnicas Biossensoriais/métodos , Humanos , Imageamento por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/métodos , Reação em Cadeia da Polimerase/métodos , Vibrio parahaemolyticus/citologia
4.
J Mol Diagn ; 19(2): 230-235, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28081922

RESUMO

We evaluated the performance of an early prototype core molecular mirroring nuclear magnetic resonance detection platform (Mentor-100) to detect toxigenic Clostridium difficile from stool. This technology uses customized nanoparticles bound to target specific oligonucleotide probes that form binaries in the presence of nucleic acid from the target microorganism. Liquid patient stool specimens were seeded with C. difficile or other Clostridium species to determine the analytical sensitivity and specificity. Samples underwent nucleic acid extraction and target amplification with probes conjugated with iron nanoparticles. Signal from nuclear magnetic resonance spin-spin relaxation time was measured to detect the presence or absence of toxigenic C. difficile. The limit of detection was <180 colony forming units per reaction of toxigenic C. difficile. No cross-reactivity was observed with nontoxigenic C. difficile, Clostridium sordellii, Clostridium perfringens, Bacillus subtilis, or Paenibacillus polymyxa at 108 colony forming units/mL. Correlation studies using frozen stool samples yielded a sensitivity of 88.4% (61 of 69) and a specificity of 87.0% (40 of 46) as compared with a commercial PCR assay for C. difficile. The area under the curve in the receiver operating characteristic curve analysis was 0.922. The prototype molecular mirroring platform showed promising performance for pathogen detection from clinical specimens. The platform design has the potential to offer a novel, low-cost alternative to currently available nucleic acid-based tests.


Assuntos
Toxinas Bacterianas/genética , Clostridioides difficile/genética , Infecções por Clostridium/diagnóstico , Infecções por Clostridium/microbiologia , Fezes/microbiologia , Espectroscopia de Ressonância Magnética , Humanos , Espectroscopia de Ressonância Magnética/métodos , Nanopartículas , Nanotecnologia , Reação em Cadeia da Polimerase , Curva ROC , Sensibilidade e Especificidade
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