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1.
Food Chem ; 338: 127932, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-32932080

RESUMO

An efficient and reliable duplex SYBR Green real-time quantitative PCR (qPCR) method for beef products adulteration detection was developed based on bovine specific and vertebrate universal primers. By analyzing the numbers, positions (Tm value) of melting curve peaks of the duplex PCR products, we simultaneously identified bovine and preliminary screened non-bovine in samples, and also semi-quantified the bovine percentage according to the area ratios of peaks. All of these were necessary for adulteration determination. The specific and universal primers were designed based on mitochondrial genes ND4 and 16S rRNA respectively, their amplicons Tm values were 72.6 ± 0.5 °C and 79-81 °C. There might be some other peaks at 74-78 °C and above 81 °C if non-bovine components existed. Thelimit of detectionwas 1 pgforbovineDNA, and1 - 30 pg fornon-bovineDNAbasedon differentspecies.


Assuntos
Compostos Orgânicos/metabolismo , Reação em Cadeia da Polimerase em Tempo Real/métodos , Carne Vermelha/análise , Animais , Bovinos , Primers do DNA/genética , Qualidade dos Alimentos
2.
Sci Rep ; 10(1): 16106, 2020 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-32999395

RESUMO

Common bunt of wheat caused by Tilletia laevis and/or T. caries (syn. T. tritici), is a major disease in wheat-growing regions worldwide that could lead to 80% or even total loss of production. Even though T. laevis can be distinguished from T. caries on the bases of morphology of teliospores using microscopy technique. However, molecular methods could serve as an additional method to quantify the pathogen. To develop a rapid diagnostic and quantify method, we employed the ISSR molecular marker for T. laevis in this study. The primer ISSR857 generated a polymorphic pattern displaying a 1385 bp T. laevis-specific DNA fragment. A pair of specific primers (L57F/L57R) was designed to amplify a sequence-characterized amplified region (SCAR) (763 bp) for the PCR detection assay. The primers amplified the DNA fragment in the tested isolates of T. laevis but failed in the related species, including T. caries. The detection limit of the primer set (L57F/L57R) was 5 ng/µl of DNA extracted from T. laevis teliospores. A SYBR Green I real-time PCR method for detecting T. laevis with a 100 fg/µl detection limit and droplet digital PCR with a high sensitivity (30 fg/µl detection limit) were developed; this technique showed the most sensitive detection compared to the SCAR marker and SYBR Green I real-time PCR. Additionally, this is the first study related the detection of T. laevis with the droplet digital PCR method.


Assuntos
Basidiomycota/genética , Compostos Orgânicos/metabolismo , Doenças das Plantas/microbiologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Triticum/microbiologia , Biomarcadores/metabolismo , Primers do DNA/genética , DNA Fúngico/genética
3.
Proc Natl Acad Sci U S A ; 117(41): 25571-25579, 2020 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-32973087

RESUMO

Optimal foraging theory provides a framework to understand how organisms balance the benefits of harvesting resources within a patch with the sum of the metabolic, predation, and missed opportunity costs of foraging. Here, we show that, after accounting for the limited environmental information available to microorganisms, optimal foraging theory and, in particular, patch use theory also applies to the behavior of marine bacteria in particle seascapes. Combining modeling and experiments, we find that the marine bacterium Vibrio ordalii optimizes nutrient uptake by rapidly switching between attached and planktonic lifestyles, departing particles when their nutrient concentration is more than hundredfold higher than background. In accordance with predictions from patch use theory, single-cell tracking reveals that bacteria spend less time on nutrient-poor particles and on particles within environments that are rich or in which the travel time between particles is smaller, indicating that bacteria tune the nutrient concentration at detachment to increase their fitness. A mathematical model shows that the observed behavioral switching between exploitation and dispersal is consistent with foraging optimality under limited information, namely, the ability to assess the harvest rate of nutrients leaking from particles by molecular diffusion. This work demonstrates how fundamental principles in behavioral ecology traditionally applied to animals can hold right down to the scale of microorganisms and highlights the exquisite adaptations of marine bacterial foraging. The present study thus provides a blueprint for a mechanistic understanding of bacterial uptake of dissolved organic matter and bacterial production in the ocean-processes that are fundamental to the global carbon cycle.


Assuntos
Comportamento Apetitivo/fisiologia , Modelos Biológicos , Compostos Orgânicos/metabolismo , Plâncton/fisiologia , Vibrio/fisiologia , GMP Cíclico , Sedimentos Geológicos , Material Particulado
4.
Parasitol Res ; 119(11): 3909-3913, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32960370

RESUMO

Trichomonas gallinae are parasitic flagellates of importance in wild and domestic birds. The parasite is worldwide distributed, and Columbine birds are its main host. Current research focuses mostly on epidemiological and phylogenetic studies. However, there is still a lack of knowledge regarding parasite-host interaction or therapy development. Real-time PCR is a useful tool for diagnostic and quantification of gene copies in a determined sample. By amplification of a 113-bp region of the 18S small subunit ribosomal RNA gene, a SYBR green-based real-time PCR assay was developed. A standard curve was prepared for quantification analysis. Assay efficiency, linearity, and dissociation analysis were successfully performed. Specificity, sensibility, and reproducibility analysis were tested. This assay could be a useful tool not only for diagnostic purposes but also for future in vivo and in vitro T. gallinae studies.


Assuntos
Aves/parasitologia , Compostos Orgânicos/metabolismo , Parasitologia/métodos , Reação em Cadeia da Polimerase em Tempo Real , Tricomoníase/diagnóstico , Trichomonas/genética , Animais , Interações Hospedeiro-Patógeno , Filogenia , RNA Ribossômico 18S/genética , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Tricomoníase/parasitologia
5.
BMC Bioinformatics ; 21(1): 309, 2020 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-32664863

RESUMO

BACKGROUND: Despite continued efforts using chemical similarity methods in virtual screening, currently developed approaches suffer from time-consuming multistep procedures and low success rates. We recently developed a machine learning-based chemical binding similarity model considering common structural features from molecules binding to the same, or evolutionarily related targets. The chemical binding similarity measures the resemblance of chemical compounds in terms of binding site similarity to better describe functional similarities that arise from target binding. In this study, we have shown how the chemical binding similarity could be used in virtual screening together with the conventional structure-based methods. RESULTS: The chemical binding similarity, receptor-based pharmacophore, chemical structure similarity, and molecular docking methods were evaluated to identify an effective virtual screening procedure for desired target proteins. When we tested the chemical binding similarity method with test sets of 51 kinases, it outperformed the traditional structural similarity-based methods as well as structure-based methods, such as molecular docking and receptor-based pharmacophore modeling, in terms of finding active compounds. We further validated the results by performing virtual screening (using the chemical binding similarity and receptor-based pharmacophore methods) against a completely blind dataset for mitogen-activated protein kinase kinase 1 (MEK1), ephrin type-B receptor 4 (EPHB4) and wee1-like protein kinase (WEE1). The in vitro kinase binding assay confirmed that 6 out of 13 (46.2%) for MEK1 and 2 out of 12 (16.7%) for EPHB4 were newly identified only by the chemical binding similarity model. CONCLUSIONS: We report that the virtual screening results could further be improved by combining the chemical binding similarity model with 3D-QSAR pharmacophore and molecular docking models. Not only the new inhibitors are identified in this study, but also many of the identified molecules have low structural similarity scores against already reported inhibitors and that show the revelation of novel scaffolds.


Assuntos
Simulação de Acoplamento Molecular , Relação Quantitativa Estrutura-Atividade , Área Sob a Curva , Sítios de Ligação , Humanos , Aprendizado de Máquina , Compostos Orgânicos/química , Compostos Orgânicos/metabolismo , Preparações Farmacêuticas/química , Preparações Farmacêuticas/metabolismo , Ligação Proteica , Proteínas Quinases/química , Proteínas Quinases/metabolismo , Curva ROC
6.
Sci Rep ; 10(1): 9885, 2020 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-32555498

RESUMO

The European medicinal leech has been used for medicinal purposes for millennia, and continues to be used today in modern hospital settings. Its utility is granted by the extremely potent anticoagulation factors that the leech secretes into the incision wound during feeding and, although a handful of studies have targeted certain anticoagulants, the full range of anticoagulation factors expressed by this species remains unknown. Here, we present the first draft genome of the European medicinal leech, Hirudo medicinalis, and estimate that we have sequenced between 79-94% of the full genome. Leveraging these data, we searched for anticoagulation factors across the genome of H. medicinalis. Following orthology determination through a series of BLAST searches, as well as phylogenetic analyses, we estimate that fully 15 different known anticoagulation factors are utilized by the species, and that 17 other proteins that have been linked to antihemostasis are also present in the genome. We underscore the utility of the draft genome for comparative studies of leeches and discuss our results in an evolutionary context.


Assuntos
Anticoagulantes/metabolismo , Genoma , Hirudo medicinalis/genética , Animais , Anticoagulantes/classificação , DNA/química , DNA/genética , DNA/metabolismo , Variações do Número de Cópias de DNA/genética , Hemostasia , Hirudinas/classificação , Hirudinas/genética , Hirudinas/metabolismo , Compostos Orgânicos/classificação , Compostos Orgânicos/metabolismo , Filogenia , Sequências de Repetição em Tandem/genética
7.
Sci Rep ; 10(1): 9942, 2020 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-32555406

RESUMO

Cold-water coral (CWC) reefs are one of the most diverse and productive ecosystems in the deep sea. Especially in periods of seasonally-reduced phytodetritus food supply, their high productivity may depend on the recycling of resources produced on the reef, such as dissolved organic matter (DOM) and bacteria. Here, we demonstrate that abundant suspension feeders Geodia barretti (high-microbial-abundance sponge), Mycale lingua (low-microbial-abundance sponge) and Acesta excavata (bivalve) are able to utilize 13C-enriched (diatom-derived) DOM and bacteria for tissue growth and respiration. While DOM was an important potential resource for all taxa, utilization of bacteria was higher for the sponges as compared to the bivalve, indicating a particle-size differentiation among the investigated suspension feeders. Interestingly, all taxa released 13C-enriched particulate organic carbon, which in turn may feed the detritus pathway on the reef. Especially A. excavata produced abundant (pseudo-)fecal droppings. A second stable-isotope tracer experiment revealed that detritivorous ophiuroids utilized these droppings. The high resource flexibility of dominant reef suspension feeders, and the efficient recycling of their waste products by the detritivore community, may provide important pathways to maintain the high productivity on cold-water coral reefs, especially in periods of low external food supply.


Assuntos
Antozoários/crescimento & desenvolvimento , Bactérias/metabolismo , Radioisótopos de Carbono/metabolismo , Recifes de Corais , Ecossistema , Compostos Orgânicos/metabolismo , Água do Mar/microbiologia , Animais , Antozoários/metabolismo , Bactérias/classificação , Radioisótopos de Carbono/análise , Temperatura Baixa , Métodos de Alimentação , Água do Mar/química
8.
J Ind Microbiol Biotechnol ; 47(6-7): 449-464, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32507955

RESUMO

Cytochrome P450 enzymes catalyse reactions of significant industrial interest but are underutilised in large-scale bioprocesses due to enzyme stability, cofactor requirements and the poor aqueous solubility and microbial toxicity of typical substrates and products. In this work, we investigate the potential for preparative-scale N-demethylation of the opium poppy alkaloid noscapine by a P450BM3 (CYP102A1) mutant enzyme in a whole-cell biotransformation system. We identify and address several common limitations of whole-cell P450 biotransformations using this model N-demethylation process. Mass transfer into Escherichia coli cells was found to be a major limitation of biotransformation rate and an alternative Gram-positive expression host Bacillus megaterium provided a 25-fold improvement in specific initial rate. Two methods were investigated to address poor substrate solubility. First, a biphasic biotransformation system was developed by systematic selection of potentially biocompatible solvents and in silico solubility modelling using Hansen solubility parameters. The best-performing biphasic system gave a 2.3-fold improvement in final product titre compared to a single-phase system but had slower initial rates of biotransformation due to low substrate concentration in the aqueous phase. The second strategy aimed to improve aqueous substrate solubility using cyclodextrin and hydrophilic polymers. This approach provided a fivefold improvement in initial biotransformation rate and allowed a sixfold increase in final product concentration. Enzyme stability and cell viability were identified as the next parameters requiring optimisation to improve productivity. The approaches used are also applicable to the development of other pharmaceutical P450-mediated biotransformations.


Assuntos
Biotransformação , Sistema Enzimático do Citocromo P-450/metabolismo , Microbiologia Industrial/métodos , Noscapina/química , Bacillus megaterium/metabolismo , Catálise , Simulação por Computador , Ciclodextrinas/química , Desmetilação , Escherichia coli/metabolismo , Mutação , Compostos Orgânicos/metabolismo , Oxirredução , Polímeros/química , Solubilidade , Solventes
9.
Arch Biochem Biophys ; 689: 108435, 2020 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-32485153

RESUMO

Actinoporins are a family of pore-forming toxins produced by sea anemones as part of their venomous cocktail. These proteins remain soluble and stably folded in aqueous solution, but when interacting with sphingomyelin-containing lipid membranes, they become integral oligomeric membrane structures that form a pore permeable to cations, which leads to cell death by osmotic shock. Actinoporins appear as multigenic families within the genome of sea anemones: several genes encoding very similar actinoporins are detected within the same species. The Caribbean Sea anemone Stichodactyla helianthus produces three actinoporins (sticholysins I, II and III; StnI, StnII and StnIII) that differ in their toxic potency. For example, StnII is about four-fold more effective than StnI against sheep erythrocytes in causing hemolysis, and both show synergy. However, StnIII, recently discovered in the S. helianthus transcriptome, has not been characterized so far. Here we describe StnIII's spectroscopic and functional properties and show its potential to interact with the other Stns. StnIII seems to maintain the well-preserved fold of all actinoporins, characterized by a high content of ß-sheet, but it is significantly less thermostable. Its functional characterization shows that the critical concentration needed to form active pores is higher than for either StnI or StnII, suggesting differences in behavior when oligomerizing on membrane surfaces. Our results show that StnIII is an interesting and unexpected piece in the puzzle of how this Caribbean Sea anemone species modulates its venomous activity.


Assuntos
Venenos de Cnidários/química , Proteínas Citotóxicas Formadoras de Poros/química , Anêmonas-do-Mar/química , Sequência de Aminoácidos , Animais , Venenos de Cnidários/metabolismo , Hemólise/efeitos dos fármacos , Modelos Moleculares , Compostos Orgânicos/química , Compostos Orgânicos/metabolismo , Proteínas Citotóxicas Formadoras de Poros/metabolismo , Anêmonas-do-Mar/metabolismo , Alinhamento de Sequência , Ovinos
10.
Sci Rep ; 10(1): 8545, 2020 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-32444654

RESUMO

Vascular calcification occurs in various diseases including atherosclerosis, chronic kidney disease and type 2 diabetes but the mechanism underlying mineral deposition remains incompletely understood. Here we examined lower limb arteries of type 2 diabetes subjects for the presence of ectopic calcification and mineral particles using histology, electron microscopy and spectroscopy analyses. While arteries of healthy controls showed no calcification following von Kossa staining, arteries from 83% of diabetic individuals examined (19/23) revealed microscopic mineral deposits, mainly within the tunica media. Mineralo-organic particles containing calcium phosphate and proteins such as albumin, fetuin-A and apolipoprotein-A1 were detected in calcified arteries. Ectopic calcification and mineralo-organic particles were observed in a majority of diabetic patients and predominantly in arteries showing hyperplasia. While a low number of subjects was examined and information about disease severity and patient characteristics is lacking, these calcifications and mineralo-organic particles may represent signs of tissue dysfunction.


Assuntos
Artérias/patologia , Arteriosclerose/patologia , Calcinose/patologia , Diabetes Mellitus Tipo 2/fisiopatologia , Minerais/metabolismo , Compostos Orgânicos/metabolismo , Artérias/metabolismo , Arteriosclerose/metabolismo , Calcinose/metabolismo , Fosfatos de Cálcio/metabolismo , Estudos de Casos e Controles , Humanos , Minerais/química , Compostos Orgânicos/química
11.
Anal Bioanal Chem ; 412(12): 2743-2754, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32322952

RESUMO

Magnetic ionic liquids (MILs) with metal-containing cations are promising extraction solvents that provide fast and high efficiency extraction of DNA. Hydrophobic MILs can be generated in situ in a methodology called in situ dispersive liquid-liquid microextraction. To consolidate the sample preparation workflow, it is desirable to directly use the DNA-enriched MIL microdroplet in the subsequent analytical detection technique. Fluorescence-based techniques employed for DNA detection often utilize SYBR Green I, a DNA binding dye that exhibits optimal fluorescence when bound to double-stranded DNA. However, the MIL may hinder the fluorescence signal of the SYBR Green I-dsDNA complex due to quenching. In this study, MILs with metal-containing cations were selected and their fluorescence quenching effects evaluated using FÓ§rster Resonance Energy Transfer and quantified using Stern-Volmer models. The MILs were based on N-substituted imidazole ligands (with butyl- and benzyl- groups as substituents) coordinated to Ni2+ or Co2+ metal centers as cations, and paired with chloride anions. The effects of NiCl2 and CoCl2 salts and of the 1-butyl-3-methylimidazolium chloride ionic liquid on the fluorophore complex were also studied to understand the components of the MIL structure that are responsible for quenching. The metal within the MIL chemical structure was found to be the main component contributing to fluorescence quenching. FÓ§rster critical distances between 11.9 and 18.8 Å were obtained for the MILs, indicating that quenching is likely not due to non-radiative energy transfer but rather to spin-orbit coupling or excited-state electron transfer. The MILs were able to be directly used in qPCR and fluorescence emission measurements using a microplate reader for detection, demonstrating their applicability in fluorescence-based detection methods. Graphical abstract.


Assuntos
DNA/análise , Fluorescência , Líquidos Iônicos , Magnetismo , Compostos Orgânicos/metabolismo , DNA/química , DNA/metabolismo , Humanos , Interações Hidrofóbicas e Hidrofílicas , Compostos Orgânicos/química , Solventes
12.
Mar Pollut Bull ; 153: 110979, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32275536

RESUMO

Within Southern California, east Pacific green sea turtles (Chelonia mydas) forage year-round, taking advantage of diverse food resources, including seagrass, marine algae, and invertebrates. Assessing persistent organic pollutants (POP) in green turtle aggregations in the Seal Beach National Wildlife Refuge (SBNWR, n = 17) and San Diego Bay (SDB, n = 25) can help quantify contamination risks for these populations. Blood plasma was analyzed for polychlorinated biphenyls (PCBs), organochlorinated pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs). PCBs and body size explained much of the separation of turtles by foraging aggregation in a principal component analysis. Turtles from SDB had significantly (p < 0.001) higher total PCBs than SBNWR turtles. Most PCBs detected in turtles were non-dioxin-like PCB congeners (153, 138, 99) that are associated with neurotoxicity. Recaptured turtles' POP levels changed significantly over time indicating significant variation in POP levels through time and space, even among adjacent foraging locations.


Assuntos
Monitoramento Ambiental , Tartarugas/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , California , Ecossistema , Compostos Orgânicos/metabolismo , Bifenilos Policlorados/metabolismo
13.
Sci Rep ; 10(1): 7121, 2020 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-32346018

RESUMO

In nitrifying biofilms, the organic carbon to ammonia nitrogen (C/N) supply ratio can influence resource competition between heterotrophic and nitrifying bacteria for oxygen and space. We investigated the impact of acute and chronic changes in carbon supply on inter-guild competition in two moving bed biofilm reactors (MBBR), operated with (R1) and without (R0) external organic carbon supply. The microbial and nitrifying community composition of the reactors differed significantly. Interestingly, acute increases in the dissolved organic carbon inhibited nitrification in R1 ten times more than in R0. A sustained increase in the carbon supply decreased nitrification efficiency and increased denitrification activity to a greater extent in R1, and also increased the proportion of potential denitrifiers in both bioreactors. The findings suggest that autotrophic biofilms subjected to increases in carbon supply show higher nitrification and lower denitrification activity than carbon-fed biofilms. This has significant implications for the design of nitrifying bioreactors. Specifically, efficient removal of organic matter before the nitrification unit can improve the robustness of the bioreactor to varying influent quality. Thus, maintaining a low C/N ratio is important in nitrifying biofilters when acute carbon stress is expected or when anoxic activity (e.g. denitrification or H2S production) is undesirable, such as in recirculating aquaculture systems (RAS).


Assuntos
Biofilmes , Carbono/metabolismo , Compostos Orgânicos/metabolismo , Aquicultura , Bactérias/metabolismo , Reatores Biológicos , Nitrificação
14.
Anal Chim Acta ; 1113: 26-35, 2020 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-32340666

RESUMO

Biophysical techniques that enable the screening and identification of weak affinity fragments against a target protein are at the heart of Fragment Based Drug Design approaches. In the case of membrane proteins, the crucial criteria for fragment screening are low protein consumption, unbiased conformational states and rapidity because of the difficulties in obtaining sufficient amounts of stable and functionally folded proteins. Here we show for the first time that lipid-nanodisc systems (membrane-mimicking environment) and miniaturized affinity chromatography can be combined to identify specific small molecule ligands that bind to an integral membrane protein. The approach was exemplified using the AA2AR GPCR. Home-made affinity nano-columns modified with nanodiscs-embedded AA2AR (only about 1 µg of protein per column) were fully characterized by frontal chromatographic experiments. This method allows (i) to distinguish specific and unspecific ligand/receptor interactions, (ii) to assess dissociation constants, (iii) to identify the binding pocket of uncharacterized ligands using a reference compound (whose binding site is known) with competition experiments. Weak affinity ligands with Kd in the low to high micromolar range can be detected. At last, the applicability of this method was demonstrated with 6 fragments recently identified as ligands or non-ligands of AA2AR.


Assuntos
Proteínas Imobilizadas/metabolismo , Nanopartículas/química , Compostos Orgânicos/análise , Receptor A2A de Adenosina/metabolismo , Cromatografia de Afinidade/métodos , Descoberta de Drogas , Humanos , Proteínas Imobilizadas/química , Ligantes , Membranas Artificiais , Compostos Orgânicos/metabolismo , Estudo de Prova de Conceito , Ligação Proteica , Receptor A2A de Adenosina/química
15.
Chem Biol Interact ; 323: 109030, 2020 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-32205154

RESUMO

The review summarizes literature data on the DNA-binding, DNA-protecting and DNA-damaging activities of a range of natural human endogenous and exogenous compounds. Small natural organic molecules bind DNA in a site-specific mode, by arranging tight touch with the structure of the major and minor grooves, as well as individual bases in the local duplex DNA. Polyphenols are the best-studied exogenous compounds from this point of view. Many of them demonstrate hormetic effects, producing both beneficial and damaging effects. An attempt to establish the dependence of DNA damage or DNA protection on the concentration of the compound turned out to be successful for some polyphenols, daidzein, genistein and resveratrol, which were DNA protecting in low concentrations and DNA damaging in high concentrations. There was no evident dependence on concentration for quercetin and kaempferol. Probably, the DNA-protecting effect is associated with the affinity to DNA. Caffeine and theophylline are DNA binders; at the same time, they favor DNA repair. Although most alkaloids damage DNA, berberine can protect DNA against damage. Among the endogenous compounds, hormones belonging to the amine class, thyroid and steroid hormones appear to bind DNA and produce some DNA damage. Thus, natural compounds continue to reveal beneficial or adverse effects on genome integrity and provide a promising source of therapeutic activities.


Assuntos
Produtos Biológicos/metabolismo , Reparo do DNA , DNA/metabolismo , Alimentos , Compostos Orgânicos/metabolismo , Produtos Biológicos/química , Hormônios/metabolismo , Compostos Orgânicos/química
16.
Chemosphere ; 251: 126391, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32143078

RESUMO

While the definition of soluble microbial products (SMP) remains somewhat contentious, they have been widely accepted to be the pool of organic compounds which are released by cells into their surroundings (liquid or otherwise) due to substrate metabolism and biomass decay. SMPs are also potential precursors of disinfection by-products, and are known to be important in membrane fouling. With recent developments in analytical methodologies, many of the low molecular weight (MW) compounds can now be identified, although they are often incorrectly identified as recalcitrant compounds present in the influent. The old hypothesis of "microbial infallibility" suggested that all organic compounds produced by bacteria will eventually be degraded by microorganisms. However, there are some limitations to this hypothesis due to; the time available for degradation, the rate of activity of the microorganisms themselves, synergistic effects, as well as the degree of complexity of the chemical substance. Therefore, it is important to identify and characterise the SMPs involved in these processes, which can then in turn support the research and development of improving wastewater treatment efficiency and effectiveness, and eventually reduce environmental damage. In addition, it is still unclear what the evolutionary purpose of these compounds are. This paper reviews the work that has been done on the production and biotransformation of chemical compounds up to now and which were reported to be found in wastewater treatment systems.


Assuntos
Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/microbiologia , Bactérias/metabolismo , Biomassa , Reatores Biológicos , Biotransformação , Desinfecção , Compostos Orgânicos/metabolismo
17.
Molecules ; 25(6)2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32183441

RESUMO

This work proposes a simple and easy-to-use flow-through system for the implementation of dynamic extractions, aiming at the evaluation of bioaccessible zinc and the characterization of leaching kinetics in dry dog food samples. The kinetic profile of Zn extraction was determined by flame atomic absorption spectroscopy and the results were fitted in an exponential function (R2 > 0.960) compatible with a two first-order reactions model. Values of fast leachable Zn ranged from 83 ± 1 to 313 ± 5 mg of Zn per kg of sample, with associated rate constants ranging from 0.162 ± 0.004 to 0.290 ± 0.014 min-1. Similar results were observed compared to the static batch extraction. The percentage of bioaccessible Zn ranged from 49.0 to 70.0%, with an average value of 58.2% in relation to total Zn content. Principal component analysis regarding the variables fast leachable Zn, associated rate constant, total Zn, and market segment, has shown that 84.6% of variance is explained by two components, where the second component (24.0%) presented loadings only for the fast leachable Zn and associated rate constant. The proposed method is suitable for the fast evaluation (<1 h) of leaching kinetics and bioaccessibility in dry dog food.


Assuntos
Zinco/química , Zinco/metabolismo , Ração Animal , Animais , Disponibilidade Biológica , Cães , Cinética , Compostos Orgânicos/química , Compostos Orgânicos/metabolismo , Análise de Componente Principal/métodos , Espectrofotometria Atômica/métodos
18.
J Biol Chem ; 295(16): 5509-5518, 2020 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-32165500

RESUMO

Neoantimycins are anticancer compounds of 15-membered ring antimycin-type depsipeptides. They are biosynthesized by a hybrid multimodular protein complex of nonribosomal peptide synthetase (NRPS) and polyketide synthase (PKS), typically from the starting precursor 3-formamidosalicylate. Examining fermentation extracts of Streptomyces conglobatus, here we discovered four new neoantimycin analogs, unantimycins B-E, in which 3-formamidosalicylates are replaced by an unusual 3-hydroxybenzoate (3-HBA) moiety. Unantimycins B-E exhibited levels of anticancer activities similar to those of the chemotherapeutic drug cisplatin in human lung cancer, colorectal cancer, and melanoma cells. Notably, they mostly displayed no significant toxicity toward noncancerous cells, unlike the serious toxicities generally reported for antimycin-type natural products. Using site-directed mutagenesis and heterologous expression, we found that unantimycin productions are correlated with the activity of a chorismatase homolog, the nat-hyg5 gene, from a type I PKS gene cluster. Biochemical analysis confirmed that the catalytic activity of Nat-hyg5 generates 3-HBA from chorismate. Finally, we achieved selective production of unantimycins B and C by engineering a chassis host. On the basis of these findings, we propose that unantimycin biosynthesis is directed by the neoantimycin-producing NRPS-PKS complex and initiated with the starter unit of 3-HBA. The elucidation of the biosynthetic unantimycin pathway reported here paves the way to improve the yield of these compounds for evaluation in oncotherapeutic applications.


Assuntos
Antibióticos Antineoplásicos/biossíntese , Proteínas de Bactérias/metabolismo , Depsipeptídeos/biossíntese , Hidroxibenzoatos/química , Policetídeo Sintases/metabolismo , Antibióticos Antineoplásicos/química , Antibióticos Antineoplásicos/toxicidade , Linhagem Celular Tumoral , Sobrevivência Celular , Depsipeptídeos/química , Depsipeptídeos/toxicidade , Humanos , Compostos Orgânicos/química , Compostos Orgânicos/metabolismo , Compostos Orgânicos/toxicidade , Streptomyces/enzimologia , Streptomyces/metabolismo
19.
Sci Rep ; 10(1): 1675, 2020 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-32015369

RESUMO

Farmland soil typical for the Polish rural environment was used in pot experiment to estimate the impact of cadmium and zinc on the manganese, lead and copper uptake by lemon balm (Melissa officinalis L). Bioavailable and total forms of investigated metals in soil and metal concentrations in plants were determined by atomic absorption spectrometry. The plant photosynthesis indicators were also examined. Intensification of photosynthesis upon the high zinc and cadmium soil supplementation was observed. This effect was not detected at low metal concentrations. ANOVA proved that cadmium and zinc treatments influenced manganese, lead and copper transfer from soil and their concentration in plants. Zinc uptake and accumulation in either roots or above-ground parts in plant was inversely proportional to cadmium concentration in soil. Manganese concentration in roots decreased upon the soil supplementation with either zinc or cadmium. It suggests that the latter ions are transported via symplastic pathways and compete with manganese for similar transporters. The opposite situation was observed for lead and copper. Soil supplementation with cadmium and zinc affects manganese, lead and copper concentrations and photosynthesis intensity in lemon balm plant. The following combined interactions in either normal or stress conditions are important indicators of the migration pathways.


Assuntos
Cádmio/metabolismo , Cobre/metabolismo , Chumbo/metabolismo , Manganês/metabolismo , Melissa/metabolismo , Zinco/metabolismo , Transporte Biológico/fisiologia , Compostos Orgânicos/metabolismo , Fotossíntese/efeitos dos fármacos , Raízes de Plantas/metabolismo , Solo/química , Poluentes do Solo/metabolismo
20.
Regul Toxicol Pharmacol ; 112: 104614, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32044383

RESUMO

Human skin is a common pathway through which chemicals in our environment enter the body. To aid with risk management of environmental chemicals, the US EPA utilizes mathematical models to estimate percutaneous penetration when experimental data is not available. Here, the accuracy of predicted flux by the Potts and Guy model based on in vitro penetration is compared to human in vivo data of percutaneous absorption of various organic compounds. For most chemicals, the flux was over- or underestimated by a factor 10-100. In vitro flux was significantly correlated to experimental human in vivo flux; however, the physiochemical parameters used in the Potts and Guy equation, Kp, Koctanol, and molecular weight, did not correlate significantly with in vivo flux. We discuss possible explanations for why the computer model did not accurately predict in vivo flux. Further research is needed with different types of chemicals encountered in the environment, and/or as used in clinical practice. This manuscript discusses limitations to the mathematical models currently used, and why the models should be further refined for use.


Assuntos
Compostos Orgânicos/metabolismo , Compostos Orgânicos/farmacocinética , Absorção Cutânea , Pele/metabolismo , Humanos , Modelos Lineares , Masculino , Compostos Orgânicos/química , Software , Estados Unidos , United States Environmental Protection Agency
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