RESUMO
OBJECTIVES: To assess the effect of one-step temperature increase, from 35 to 55 °C, on the methane production of a mesophilic granular sludge (MGS) treating wine vinasses and the effluent of a hydrogenogenic upflow anaerobic sludge blanket (UASB) reactor. RESULTS: One-step temperature increase from mesophilic to thermophilic conditions improved methane production regardless of the substrate tested. The biomethane potentials obtained under thermophilic conditions were 1.8-2.9 times higher than those obtained under mesophilic conditions. The MGS also performed better than an acclimated thermophilic digestate, producing 2.2-2.5 times more methane than the digestate under thermophilic conditions. Increasing the temperature from 35 to 55 °C also improved the methane production rate of the MGS (up to 9.4 times faster) and reduced the lag time (up to 1.9 times). Although the temperature increase mediated a decrease in the size of the sludge granules, no negative effects on the performance of the MGS was observed under thermophilic conditions. CONCLUSIONS: More methane is obtained from real agroindustrial effluents at thermophilic conditions than under mesophilic conditions. One-step temperature increase (instead of progressive sequential increases) can be used to implement the thermophilic anaerobic digestion processes with MGS.
Assuntos
Agroquímicos/metabolismo , Metano/metabolismo , Esgotos/química , Temperatura , Eliminação de Resíduos Líquidos/métodos , Agroquímicos/análise , Agroquímicos/isolamento & purificação , Anaerobiose , Biocombustíveis , Reatores Biológicos , Metano/análiseRESUMO
Fusarium head blight (FHB) is one of the most destructive diseases of wheat and other cereals worldwide. During infection, the Fusarium fungi produce mycotoxins that represent a high risk to human and animal health. Developing small-molecule inhibitors to specifically reduce mycotoxin levels would be highly beneficial since current treatments unspecifically target the Fusarium pathogen. Culmorin possesses a well-known important synergistically virulence role among mycotoxins, and longiborneol synthase appears to be a key enzyme for its synthesis, thus making longiborneol synthase a particularly interesting target. This study aims to discover potent and less toxic agrochemicals against FHB. These compounds would hamper culmorin synthesis by inhibiting longiborneol synthase. In order to select starting molecules for further investigation, we have conducted a structure-based virtual screening investigation. A longiborneol synthase structural model is first built using homology modeling, followed by molecular dynamics simulations that provided the required input for a protein-ligand ensemble docking procedure. From this strategy, the three most interesting compounds (hits) were selected among the 25 top-ranked docked compounds from a library of 15,000 drug-like compounds. These putative inhibitors of longiborneol synthase provide a sound starting point for further studies involving molecular modeling coupled to biochemical experiments. This process could eventually lead to the development of novel approaches to reduce mycotoxin contamination in harvested grain.
Assuntos
Inibidores Enzimáticos/metabolismo , Proteínas Fúngicas/metabolismo , Fusarium/enzimologia , Ensaios de Triagem em Larga Escala/métodos , Ligases/metabolismo , Sesquiterpenos/metabolismo , Agroquímicos/química , Agroquímicos/metabolismo , Agroquímicos/farmacologia , Sequência de Aminoácidos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Proteínas Fúngicas/química , Proteínas Fúngicas/classificação , Fusarium/metabolismo , Fusarium/patogenicidade , Ligases/antagonistas & inibidores , Ligases/genética , Modelos Moleculares , Estrutura Molecular , Filogenia , Doenças das Plantas/microbiologia , Ligação Proteica , Domínios Proteicos , Homologia de Sequência de AminoácidosRESUMO
A recent review article entitled "Carbon and fullerene nanomaterials in plant system" published in this journal, misinterprets a component of our (published) work on the interactions of carbon nanotubes with plants. In this comment, we provide the rationale to counter this misconstruction.
Assuntos
Agroquímicos/metabolismo , Carbono/metabolismo , Cucurbitaceae/crescimento & desenvolvimento , Fulerenos/metabolismo , Nanoestruturas/química , Solanum lycopersicum/crescimento & desenvolvimentoRESUMO
The purpose of this work is the definition and evaluation of both atomic and local new hybrid indices. Inspired by the Refractotopological State Index for Atoms, the new atomic indices are theoretically supported by graph theory principles. The local indices, named Descriptor Centres (DCs), are obtained from the sum of the atomic values of the atoms in the selected group. Different classifiers were used for structure-activity relationship (SAR) studies, including multilayer perceptron (MLP), support vector machines (SVM) and meta-classifiers. Prediction with SVM and MLP was around 60%, but the best result was obtained with the meta-classifiers, bagging, decorate and others, with more than 92% accurate prediction. These new hybrid descriptors derived from the Refractotopological State Index for Atoms show a low mutual correlation coefficient. The same behaviour is found in the analogously defined Descriptors Centres. The best results are obtained with the inclusion of the distance between DCs with the use of meta-classifiers.
Assuntos
Simulação por Computador , Modelos Moleculares , Estrutura Molecular , Relação Estrutura-Atividade , Agroquímicos/química , Agroquímicos/metabolismo , Fenômenos Químicos , Preparações Farmacêuticas/química , Preparações Farmacêuticas/metabolismo , Tecnologia Farmacêutica/métodosRESUMO
This paper aims to evaluate the genotoxic effect of agrochemicals in rural workers occupationally exposed by the micronucleus assay in peripheral blood lymphocytes and to promote the development of health and environmental preventive and protective practices. A total of 30 blood samples from 20 individuals occupationally exposed to different agrochemicals and 10 unexposed persons, who formed the reference group, were analyzed. We found statistically significant differences (p < 0.0005, Student's t Test) in the frequency of micronuclei between the two groups (7.20 ± 1.55 and 15.15 ± 5.10 CBMN for reference and exposed groups respectively). The analysis of age showed a positive correlation (Pearson Correlation Test) with the frequency of micronuclei in exposed population (p < 0.05; r(2) = 0.47), in contrast with smoking habits and years of exposure. Micronucleus assay allows an early detection of populations at higher risk of having genetic damage, allowing us to implement strategies of intervention for the purpose of contributing to reduce that risk.