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1.
Chemosphere ; 240: 124903, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31563100

RESUMO

Excessive nitrogen has been a global concern to cause lake eutrophication. The denitrification and anammox processes are considered to be effective biological pathways for nitrogen removal. Submerged macrophytes also play a key role in the nitrogen cycle of lakes. However, the mechanism of submerged macrophytes on regulating biological nitrogen removal pathways has not been well quantified. Therefore, this study investigated the impacts of submerged macrophytes on the community structures and abundance of the nirS-type denitrifiers and anammox bacteria in the rhizospheres. The qPCR results indicated that the abundance of two bacteria in the near-rhizospheres of submerged macrophytes was significantly lower than the root compartments and non-rhizospheres, while the concentrations of organic acids in the near-rhizospheres were higher than those of the root compartments and non-rhizospheres. Redundancy analysis results illustrated that concentrations of NO3--N, NO2--N, citric acid and oxalic acid were the key environmental indicators which had the significant impact on the microbial community. The concentrations of citric acid and oxalic acid were negatively correlated with the nirS-type denitrifiers abundance, and the oxalic acid concentrations were negatively correlated with the anammox bacteria abundance. These results indicated that submerged macrophytes could reduce the abundance of nirS-type denitrifiers and anammox bacteria by releasing organic acids. In addition, the highest diversity of denitrifier community were found in the rhizosphere of the Hydrilla verticillata, while the highest diversity of anammox community were found in the Potamogeton maackianus rhizosphere. These results indicate that the impacts of submerged macrophytes on the biological nitrogen removal pathways were species-dependent.


Assuntos
Biodegradação Ambiental , Desnitrificação/genética , Rizosfera , Microbiologia do Solo , Bactérias/metabolismo , Eutrofização , Hydrocharitaceae/metabolismo , Lagos/química , Nitrogênio/química , Ciclo do Nitrogênio , Compostos Orgânicos/metabolismo , Potamogetonaceae/microbiologia
2.
Ecotoxicol Environ Saf ; 186: 109810, 2019 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-31629190

RESUMO

Little is known about how the chemical properties (molecular structure, such as the hydrophobic and hydrophilic end group for organic chemical, and particle size for nanomaterials (NMs)) quantitatively affect the toxicokinetics (TK) in organisms especially in short-term, single-species studies. A novel method based on a first-order one compartment TK model which described the monophasic uptake pattern and two-compartment TK model which adequately described the biphasic metabolism pattern was used to determine the bioconcentration and TK rate constants of organic compounds (n = 17) and nanomaterials (NMs, n = 7) in zebrafish. For both one and two compartment model, the uptake (kin) and elimination (kout) rate constants were fitted using a one- and two-compartment first-order kinetic model, and bioconcentration factors (BCF) and 95% depuration times (t95) for all tested chemicals were calculated, respectively. The results showed that there was significant difference in TK parameters kin, kout, and BCF between organic chemicals and nano metal oxides. For organic compounds, significant correlations were found between the kin and BCF and the octanol-water partition coefficient (Kow) and molecular mass. For nano metal oxides, there was a significant negative correlation between the kin or BCF and particle size, but a positive correlation between kin and Zeta potential of nanoparticles and also a significant positive correlation between kout and particle size or specific surface area. Those findings indicated that NMs particle size does matter in biological influx and efflux processes. Our results suggest that the TK process for organic compound and NMs are correlated by different chemical properties and highlight that the Kow, the absorption kin, metabolism k12 and k21, elimination rate kout, and all the parameters that enable the prediction and partitioning of chemicals need to be precisely determined in order to allow an effective TK modeling. It would therefore appear that the TK process of untested chemicals by a fish may be extrapolated from known chemical properties.


Assuntos
Nanoestruturas/química , Compostos Orgânicos/química , Compostos Orgânicos/toxicidade , Poluentes Químicos da Água/química , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/metabolismo , Animais , Embrião não Mamífero/efeitos dos fármacos , Embrião não Mamífero/metabolismo , Modelos Teóricos , Nanoestruturas/toxicidade , Compostos Orgânicos/metabolismo , Toxicocinética , Poluentes Químicos da Água/metabolismo
3.
Nat Commun ; 10(1): 4556, 2019 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-31591394

RESUMO

The chemistry of the Early Earth is widely inferred from the elemental and isotopic compositions of sulfidic sedimentary rocks, which are presumed to have formed globally through the reduction of seawater sulfate or locally from hydrothermally supplied sulfide. Here we argue that, in the anoxic Archean oceans, pyrite could form in the absence of ambient sulfate from organic sulfur contained within living cells. Sulfides could be produced through mineralization of reduced sulfur compounds or reduction of organic-sourced sulfite. Reactive transport modeling suggests that, for sulfate concentrations up to tens of micromolar, organic sulfur would have supported 20 to 100% of sedimentary pyrite precipitation and up to 75% of microbial sulfur reduction. The results offer an alternative explanation for the low range of δ34S in Archean sulfides, and raise a possibility that sulfate scarcity delayed the evolution of dissimilatory sulfate reduction until the initial ocean oxygenation around 2.7 Ga.


Assuntos
Compostos Orgânicos/metabolismo , Sulfatos/metabolismo , Compostos de Enxofre/metabolismo , Enxofre/metabolismo , Sedimentos Geológicos/química , Ferro/metabolismo , Oxirredução , Água do Mar/química , Sulfetos/metabolismo , Sulfitos/metabolismo , Isótopos de Enxofre/metabolismo
4.
Chemosphere ; 236: 124381, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31545190

RESUMO

Biological sulfur reduction is an attractive sulfidogenic technology for the treatment of organics-deficient metal-laden wastewater, because it theoretically reduces the electron donor consumption by 75%, compared to sulfate reduction. However, reducing the external organic substrate dosage may lower the sulfur reduction rate. Supplying with a more biodegradable organic substrate could possibly enhance sulfidogenic activity but also increase the chemical cost. Therefore, the sulfide production performance of a sulfur-reducing bioreactor feeding with varied levels of organic supply, and different types of organic substrates were investigated. The results showed that high-rate sulfide production (12.30 mg S/L/h) in a sulfur-reducing bioreactor can be achieved at the minimal dosage of organic substrate as low as 39 mg C/L of organic carbon in the influent. Changing the type of organic substrate posed a significant effect on the sulfidogenic activity in the sulfur-reducing bioreactor. Sodium acetate was found to be the optimal substrate to achieve the highest sulfide production rate (28.20 mg S/L/h) by sulfur-reducing bacteria (S0RB), followed by ethanol, methanol, glycerol, pyruvic acid, acetic acid, glucose, sucrose, malic acid, sodium formate, formic acid, N-propanol, N-butanol, lactic acid, sodium lactate, propionic acid and sodium propionate (2.87 mg S/L/h as the lowest rate). However, the cost-effectiveness analysis showed that glucose was the most cost-effective organic substrate to realize the sulfur reduction process in high sulfide production rate (20.13 mg S/L/h) and low chemical cost (5.94 kg S/$). The utilization pathway of the different organic substrates in the sulfur-reducing bioreactor was also discussed.


Assuntos
Reatores Biológicos/microbiologia , Compostos Orgânicos/análise , Bactérias Redutoras de Enxofre/metabolismo , Enxofre/metabolismo , Purificação da Água/métodos , Reatores Biológicos/economia , Análise Custo-Benefício , Metais/metabolismo , Compostos Orgânicos/economia , Compostos Orgânicos/metabolismo , Oxirredução , Sulfatos/metabolismo , Sulfetos/metabolismo , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/microbiologia , Purificação da Água/economia
5.
BMC Plant Biol ; 19(1): 383, 2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-31481025

RESUMO

BACKGROUND: Organic acid secretion is a widespread physiological response of plants to alkalinity. However, the characteristics and underlying mechanism of the alkali-induced secretion of organic acids are poorly understood. RESULTS: Oxalate was the main organic acid synthesized and secreted in grapevine (a hybrid of Vitis amurensis, V. berlandieri and V. riparia) roots, while acetate synthesis and malate secretion were also promoted under NaHCO3 stress. NaHCO3 stress enhanced the H+ efflux rate of grapevine roots, which is related to the plasma membrane H+-ATPase activity. Transcriptomic profiling revealed that carbohydrate metabolism was the most significantly altered biological process under NaHCO3 stress; a total of seven genes related to organic acid metabolism were significantly altered, including two phosphoenolpyruvate carboxylases and phosphoenolpyruvate carboxylase kinases. Additionally, the expression levels of five ATP-binding cassette transporters, particularly ATP-binding cassette B19, and two Al-activated malate transporter 2 s were substantially upregulated by NaHCO3 stress. Phosphoproteomic profiling demonstrated that the altered phosphoproteins were primarily related to binding, catalytic activity and transporter activity in the context of their molecular functions. The phosphorylation levels of phosphoenolpyruvate carboxylase 3, two plasma membrane H+-ATPases 4 and ATP-binding cassette B19 and pleiotropic drug resistance 12 were significantly increased. Additionally, the inhibition of ethylene synthesis and perception completely blocked NaHCO3-induced organic acid secretion, while the inhibition of indoleacetic acid synthesis reduced NaHCO3-induced organic acid secretion. CONCLUSIONS: Our results demonstrated that oxalate was the main organic acid produced under alkali stress and revealed the necessity of ethylene in mediating organic acid secretion. Additionally, we further identified several candidate genes and phosphoproteins responsible for organic acid metabolism and secretion.


Assuntos
Proteínas de Plantas/genética , Proteoma/genética , Bicarbonato de Sódio/metabolismo , Transcriptoma , Vitis/genética , Vitis/metabolismo , Ácidos/metabolismo , Compostos Orgânicos/metabolismo , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/metabolismo , Proteoma/metabolismo
6.
Nat Commun ; 10(1): 3982, 2019 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-31484931

RESUMO

Boreal forests are ecosystems with low nitrogen (N) availability that store globally significant amounts of carbon (C), mainly in plant biomass and soil organic matter (SOM). Although crucial for future climate change predictions, the mechanisms controlling boreal C and N pools are not well understood. Here, using a three-year field experiment, we compare SOM decomposition and stabilization in the presence of roots, with exclusion of roots but presence of fungal hyphae and with exclusion of both roots and fungal hyphae. Roots accelerate SOM decomposition compared to the root exclusion treatments, but also promote a different soil N economy with higher concentrations of organic soil N compared to inorganic soil N accompanied with the build-up of stable SOM-N. In contrast, root exclusion leads to an inorganic soil N economy (i.e., high level of inorganic N) with reduced stable SOM-N build-up. Based on our findings, we provide a framework on how plant roots affect SOM decomposition and stabilization.


Assuntos
Ecossistema , Compostos Orgânicos/metabolismo , Raízes de Plantas/metabolismo , Solo/química , Taiga , Biomassa , Carbono/metabolismo , Hifas/fisiologia , Modelos Biológicos , Nitrogênio/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , Plantas/metabolismo , Plantas/microbiologia , Microbiologia do Solo
7.
J Microbiol Biotechnol ; 29(9): 1434-1443, 2019 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-31434363

RESUMO

Although chemical oxygen demand (COD) is an important issue for wastewater treatment, COD reduction with microalgae has been less studied compared to nitrogen or phosphorus removal. COD removal is not efficient in conventional wastewater treatment using microalgae, because the algae release organic compounds, thereby finally increasing the COD level. This study focused on enhancing COD removal and meeting the effluent standard for discharge by optimizing sludge inoculation timing, which was an important factor in forming a desirable algae/bacteria consortium for more efficient COD removal and higher biomass productivity. Activated sludge has been added to reduce COD in many studies, but its inoculation was done at the start of cultivation. However, when the sludge was added after 3 days of cultivation, at which point the COD concentration started to increase again, the algal growth and biomass productivity were higher than those of the initial sludge inoculation and control (without sludge). Algal and bacterial cell numbers measured by qPCR were also higher with sludge inoculation at 3 days later. In a semi-continuous cultivation system, a hydraulic retention time of 5 days with sludge inoculation resulted in the highest biomass productivity and N/P removal. This study achieved a further improved COD removal than the conventional microalgal wastewater treatment, by introducing bacteria in activated sludge at optimized timing.


Assuntos
Microalgas/metabolismo , Esgotos/microbiologia , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/isolamento & purificação , Bactérias/crescimento & desenvolvimento , Bactérias/metabolismo , Biodegradação Ambiental , Análise da Demanda Biológica de Oxigênio , Biomassa , Reatores Biológicos/microbiologia , Microalgas/crescimento & desenvolvimento , Consórcios Microbianos , Nitrogênio/isolamento & purificação , Nitrogênio/metabolismo , Compostos Orgânicos/isolamento & purificação , Compostos Orgânicos/metabolismo , Fósforo/isolamento & purificação , Fósforo/metabolismo , Esgotos/química , Fatores de Tempo , Poluentes Químicos da Água/metabolismo
8.
Int J Food Microbiol ; 307: 108270, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31408740

RESUMO

Aspergillus oryzae is an important microbial starter for making diverse fermented foods due to its high hydrolytic enzyme activities. In this study, two strains of A. oryzae (AOB/AOK) with different activities of hydrolytic enzymes, such as α-amylase, protease and lipase, were cultured under various conditions of temperature, fermentation time, and initial pH. Comparative mass spectrometry (MS) based metabolomic analysis was performed to obtain primary metabolites and secondary volatile metabolite data sets. In the results of partial least square-discriminant analysis (PLS-DA), fatty acids and volatile metabolites derived from fatty acids and amino acids mainly contributed to AOK with higher protease and lipase activities, whereas carbohydrate-derived volatiles, sugars and sugar alcohols were related to main metabolites of AOB with higher α-amylase activity. The temperature and initial pH were critical factors for the generation of primary metabolites and secondary volatile metabolites, such as organic acids, fatty acids-derived volatiles, and some amino acids, in both A. oryzae strains. This study demonstrated that the specific culture conditions were closely linked to the formation of primary metabolites and secondary volatile metabolites of A. oryzae.


Assuntos
Aspergillus oryzae/metabolismo , Metabolômica , Aspergillus oryzae/enzimologia , Fermentação , Concentração de Íons de Hidrogênio , Lipase/metabolismo , Compostos Orgânicos/análise , Compostos Orgânicos/metabolismo , Peptídeo Hidrolases/metabolismo , Temperatura Ambiente , alfa-Amilases/metabolismo
9.
Appl Microbiol Biotechnol ; 103(19): 8255-8265, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31396677

RESUMO

Coupling algal cultivation with wastewater treatment due to their potentials to alleviate energy crisis and reduce environmental burden has attracted the increased attention in recent years. However, these microalgal-based processes are challenging since daily and seasonal temperature fluctuation may affect microalgal growth in wastewater, and the effects of the temperature regimes on microalgal biomass production and wastewater nutrient removal remain unclear. In this study, Chlorella vulgaris was continuously cultured for 15 days in municipal wastewater to investigate the effects on the algal biomass and wastewater nutrient removal in three temperature regimes: (1) low temperature (4 °C), (2) high temperature (35 °C), and (3) alternating high-low temperature (35 °C in the day: 4 °C at night). Compared with the other two temperature regimes, the high-low temperature conditions generated the most biomass (1.62 g L-1), the highest biomass production rate (99.21 mg L-1 day-1), and most efficient removal of COD, TN, NH3-N, and TP (83.0%, 96.5%, 97.8%, and 99.2%, respectively). In addition, the polysaccharides, proteins, lipid content, and fatty acid methyl ester composition analysis indicates that in alternating high-low temperature condition, biomass production increased the potential for biofuel production, and there was the highest lipid content (26.4% of total dry biomass). The results showed that the nutrients except COD were all efficiently removed in these temperature conditions, and the alternating high-low temperature condition showed great potential to generate algal biomass and alleviate the wastewater nutrients. This study provides some valuable information for large-scale algal cultivation in wastewater and microalgal-based wastewater treatments.


Assuntos
Chlorella vulgaris/crescimento & desenvolvimento , Chlorella vulgaris/efeitos da radiação , Compostos Orgânicos/metabolismo , Temperatura Ambiente , Águas Residuárias/microbiologia , Poluentes Químicos da Água/metabolismo , Purificação da Água/métodos , Biomassa , Lipídeos/análise , Polissacarídeos/análise , Proteínas/análise , Águas Residuárias/química
10.
Int J Mol Sci ; 20(14)2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31340593

RESUMO

Normothermic machine perfusion (NMP) of kidneys offers the opportunity to perform active interventions, such as the addition of mesenchymal stromal cells (MSCs), to an isolated organ prior to transplantation. The purpose of this study was to determine whether administering MSCs to kidneys during NMP is feasible, what the effect of NMP is on MSCs and whether intact MSCs are retained in the kidney and to which structures they home. Viable porcine kidneys were obtained from a slaughterhouse. Kidneys were machine perfused during 7 h at 37 °C. After 1 h of perfusion either 0, 105, 106 or 107 human adipose tissue derived MSCs were added. Additional ex vivo perfusions were conducted with fluorescent pre-labelled bone-marrow derived MSCs to assess localisation and survival of MSCs during NMP. After NMP, intact MSCs were detected by immunohistochemistry in the lumen of glomerular capillaries, but only in the 107 MSC group. The experiments with fluorescent pre-labelled MSCs showed that only a minority of glomeruli were positive for infused MSCs and most of these glomeruli contained multiple MSCs. Flow cytometry showed that the number of infused MSCs in the perfusion circuit steeply declined during NMP to approximately 10%. In conclusion, the number of circulating MSCs in the perfusate decreases rapidly in time and after NMP only a small portion of the MSCs are intact and these appear to be clustered in a minority of glomeruli.


Assuntos
Rastreamento de Células/métodos , Glomérulos Renais/ultraestrutura , Transplante de Rim , Transplante de Células-Tronco Mesenquimais/métodos , Células-Tronco Mesenquimais/citologia , Perfusão/métodos , Adipócitos/citologia , Adipócitos/fisiologia , Animais , Células da Medula Óssea/citologia , Células da Medula Óssea/fisiologia , Diferenciação Celular , Corantes Fluorescentes/metabolismo , Humanos , Glomérulos Renais/cirurgia , Transplante de Células-Tronco Mesenquimais/instrumentação , Células-Tronco Mesenquimais/fisiologia , Microscopia de Fluorescência , Preservação de Órgãos/métodos , Compostos Orgânicos/metabolismo , Perfusão/instrumentação , Suínos , Temperatura Ambiente , Transplante Heterólogo
11.
Microb Pathog ; 134: 103595, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31201902

RESUMO

The persistence of pathogenic bacteria in the marine environment has been thoroughly investigated. The potential threat that these microorganisms pose to public health in recreational waters has always been a concern. In this study, the persistence and the response of Pseudomonas aeruginosa ATCC27853 to starvation and osmotic stress were studied after its incubation in sterilized seawater during 12 months. Three different colonial variants were isolated: A7 after one month, and A81 and A82 after 8 months of incubation period. The incubation effect on the bacterial phenotype and genotype were studied by analyzing modifications in morphology, antibiotic and metal resistance, molecular typing (PFGE and MLST), pigment production and virulence factors. The starved variants showed three different colony forms, but an indistinguishable PFGE pattern and belonged to ST155, as P. aeruginosa ATCC27853. The starved variants maintained the susceptibility to the 13 tested antibiotics, with the exception of the imipenem-resistant A82 strain, which also showed a small colony variant phenotype and the highest values of tolerance to the CuSO4 + NaCl combination. Significant differences were detected in the pigment production, the elastase activity and cytotoxic potential of the starved isolates in comparison to P. aeruginosa ATCC27853. Long-term exposure to stress, such as the incubation in seawater, was shown to induce different responses in P. aeruginosa, including virulent and resistant phenotypes.


Assuntos
Pseudomonas aeruginosa/crescimento & desenvolvimento , Pseudomonas aeruginosa/fisiologia , Água do Mar/microbiologia , Inanição , Estresse Fisiológico/fisiologia , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Biofilmes/crescimento & desenvolvimento , Contagem de Colônia Microbiana , Sulfato de Cobre/farmacologia , Farmacorresistência Bacteriana/genética , Farmacorresistência Bacteriana/fisiologia , Eletroforese em Gel de Campo Pulsado , Regulação Bacteriana da Expressão Gênica , Genes Bacterianos , Variação Genética/efeitos dos fármacos , Variação Genética/fisiologia , Genótipo , Imipenem/farmacologia , Testes de Sensibilidade Microbiana , Viabilidade Microbiana , Tipagem de Sequências Multilocus , Compostos Orgânicos/metabolismo , Pressão Osmótica , Elastase Pancreática/metabolismo , Fenazinas/metabolismo , Fenótipo , Pigmentos Biológicos/metabolismo , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/genética , Piocianina/metabolismo , Tolerância ao Sal/genética , Tolerância ao Sal/fisiologia , Alinhamento de Sequência , Cloreto de Sódio/farmacologia , Estresse Fisiológico/genética , Fatores de Tempo , Fatores de Virulência
12.
Inorg Chem ; 58(20): 13509-13527, 2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31247877

RESUMO

According to the amyloid cascade hypothesis, metal ions, mainly Cu and Zn ions, bound to the amyloid-ß (Aß) peptides are implicated in Alzheimer's disease (AD), a widespread neurodegenerative disease. They indeed impact the aggregation pathways of Aß and are involved in the catalytic generation of reactive oxygen species (ROS) that participate in oxidative stress, while Aß aggregation and oxidative stress are regarded as two key events in AD etiology. Cu ions due to their redox ability have been considered to be the main potential therapeutic targets in AD. A considerable number of ligands have been developed in order to modulate the toxicity associated with Cu in this context, via disruption of the Aß-Cu interaction. Among them, small synthetic ligands and small peptide scaffolds have been designed and studied for their ability to remove Cu from Aß. Some of those ligands are able to prevent Cu(Aß)-induced ROS production and can modify the aggregation pathways of Aß in vitro and in cellulo. Examples of such ligands are gathered in this Viewpoint, as a function of their structures and discussed with respect to their properties against Cu(Aß) deleterious fallouts. Nevertheless, the beneficial activities of the most promising ligands detected in vitro and in cellulo have not been transposed to human yet. Some parameters that might explain this apparent contradiction and key concepts to consider for the design of "more" efficient ligands are thus reported and discussed. En passant, this Viewpoint sheds light on the difficulties in comparing the results from one study to another that hamper significant advances in the field.


Assuntos
Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Cobre/metabolismo , Compostos Orgânicos/metabolismo , Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/antagonistas & inibidores , Sobrevivência Celular/efeitos dos fármacos , Humanos , Compostos Orgânicos/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Zinco/metabolismo
13.
PLoS One ; 14(5): e0216946, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31083701

RESUMO

Antimicrobial peptides (AMPs) are important components of the host innate defense mechanism against invading microorganisms. Although AMPs are known to act on bacterial membranes and increase membrane permeability, the action mechanism of most AMPs still remains unclear. In this report, we found that the TP4 peptides from Nile tilapia anchored on E. coli cells and enabled them permeable to SYTOX Green in few minutes after TP4 addition. TP4 peptides existed in small dots either on live or glutaraldehyde-fixed cells. TP4 peptides were driven into oligomers either in soluble or insoluble form by a membrane-mimicking anionic surfactant, sarkosyl, depending on the concentrations employed. The binding forces among TP4 components were mediated through hydrophobic interaction. The soluble oligomers were negatively charged on surface, while the insoluble oligomers could be fused with each other or piled on existing particles to form larger particles with diameters 0.1 to 20 µm by hydrophobic interactions. Interestingly, the morphology and solubility of TP4 particles changed with the concentration of exogenous sarkosyl or trifluoroethanol. The TP4 peptides were assembled into oligomers on or in bacterial membrane. This study provides direct evidence and a model for the oligomerization and insertion of AMPs into bacterial membrane before entering into cytosol.


Assuntos
Antibacterianos/química , Peptídeos Catiônicos Antimicrobianos/química , Membrana Celular/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Proteínas de Peixes/química , Tensoativos/farmacologia , Animais , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/isolamento & purificação , Peptídeos Catiônicos Antimicrobianos/farmacologia , Transporte Biológico , Membrana Celular/metabolismo , Permeabilidade da Membrana Celular/efeitos dos fármacos , Ciclídeos/fisiologia , Escherichia coli/metabolismo , Proteínas de Peixes/isolamento & purificação , Proteínas de Peixes/farmacologia , Corantes Fluorescentes/metabolismo , Interações Hidrofóbicas e Hidrofílicas , Compostos Orgânicos/metabolismo , Ligação Proteica , Multimerização Proteica , Sarcosina/análogos & derivados , Sarcosina/farmacologia , Eletricidade Estática , Trifluoretanol/farmacologia
14.
Top Curr Chem (Cham) ; 377(3): 17, 2019 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-31134390

RESUMO

In this article, the utilization of fungi for the degradation of xenobiotic organic compounds (XOCs) from different wastewater and aqueous solutions has been reviewed. The myco-remediation (myco-enzymes, myco-degradation, and myco-sorption) process is widely used to remove XOCs, which are not easily biodegradable. The removal of XOCs from textile wastewaters through chemical and physical processes has been addressed by many researchers. Currently, the application of oxidative enzymes [manganese peroxidase (MnP), lignin peroxidase (LiP), and laccase] and myco-adsorption is becoming more common for the removal of XOCs from wastewater. Although the advanced oxidation process (AOPs) is a preferred technology for removing XOCs, its use is restricted due to its relatively high cost, which led to research studies on non-traditional and low-cost technology. The current review aimed to organize the scattered available information on the potential of myco-remediation for XOC removal. Moreover, the utilization of agricultural wastes as a production substrate for oxidative enzymes has been reported by many authors. Agricultural waste materials are highly inducible for oxidative enzyme production by fungi and are cost-effective in comparison to commercial substances. It is evident from the literature survey of 80 recently published papers that myco-enzymes have demonstrated outstanding XOC removal capabilities. Fungal laccase enzyme is the first step to degrade the lignin and then to get the carbon source form the cellulose by cellulose enzyme.


Assuntos
Biodegradação Ambiental , Compostos Orgânicos/metabolismo , Xenobióticos/metabolismo , Adsorção , Fungos/enzimologia , Oxirredutases/metabolismo , Eliminação de Resíduos Líquidos
15.
PLoS One ; 14(5): e0217077, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31145729

RESUMO

The light fraction of soil organic matter (LF) has a rapid turnover and may be potentially metal-enriched, but the interaction between this pool of organic matter and trace elements has not been well studied. The present study aimed to investigate changes in LF content and its effect on heavy metals distribution and extractability in long-term contaminated soil by smelting activity. An incubation experiment was conducted on a surface horizon of Brunic Arenosol sampled from the previously-existing sanitary zone of Glogów smelter, for 450 days. The contaminated soil was divided into three combinations: with the addition of either triticate straw (at the dose of 4.5 Mg ha-1) or pig manure (at the dose of 40 Mg ha-1) or without any "foreign" organic materials (nil). The LF (ρ > 1.7 g cm-3) occurred to be metal-enriched and despite its low content (5.49%-nil, 7.18%-straw and 7.29%-manure combination) in the bulk soil, it was observed that initially Cd, Cu, Pb and Zn stock reached 16.2%, 11.9%, 18.0% and 32.3%, respectively. Incubation conditions where mineralization processes dominate led to a decrease in the LF share by about 12.6% in nil and 31.4-39.8% in the combinations with organic amendments. In consequence, the DOC (dissolved organic carbon) concentration doubled and metal distribution had changed. The increase in water-soluble (F1) fraction was observed for all metals, additionally for Cu, Pb, Zn in exchangeable fraction (F2) and in carbonate bound (F3) fraction for Cd and Zn. These results support the view that changes in the LF content may play a key role in controlling trace metals mobility, especially in long-term contaminated soil.


Assuntos
Biodegradação Ambiental , Esterco/análise , Compostos Orgânicos/metabolismo , Solo/química , Oligoelementos/metabolismo , Animais , Suínos , Oligoelementos/análise
16.
Sci Total Environ ; 659: 419-441, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31096373

RESUMO

While there has been a significant recent improvement in the removal of pollutants in natural and engineered systems, trace organic chemicals (TrOCs) are posing a major threat to aquatic environments and human health. There is a critical need for developing potential strategies that aim at enhancing metabolism and/or cometabolism of these compounds. Recently, knowledge regarding biodegradation of TrOCs by ammonia-oxidizing bacteria (AOB) has been widely developed. This review aims to delineate an up-to-date version of the ecophysiology of AOB and outline current knowledge related to biodegradation efficiencies of the frequently reported TrOCs by AOB. The paper also provides an insight into biodegradation pathways by AOB and transformation products of these compounds and makes recommendations for future research of AOB. In brief, nitrifying WWTFs (wastewater treatment facilities) were superior in degrading most TrOCs than non-nitrifying WWTFs due to cometabolic biodegradation by the AOB. To fully understand and/or enhance the cometabolic biodegradation of TrOCs by AOB, recent molecular research has focused on numerous crucial factors including availability of the compounds to AOB, presence of growth substrate (NH4-N), redox potentials, microorganism diversity (AOB and heterotrophs), physicochemical properties and operational parameters of the WWTFs, molecular structure of target TrOCs and membrane-based technologies, may all significantly impact the cometabolic biodegradation of TrOCs. Still, further exploration is required to elucidate the mechanisms involved in biodegradation of TrOCs by AOB and the toxicity levels of formed products.


Assuntos
Amônia/metabolismo , Bactérias/metabolismo , Compostos Orgânicos/metabolismo , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/análise , Poluentes Químicos da Água/metabolismo , Biodegradação Ambiental , Oxirredução
17.
Sci Total Environ ; 659: 463-472, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31096376

RESUMO

Application of biochars produced by pyrolyzing organic residues to cropland has been proposed to be an effective approach to better use of organic residues, decrease soil greenhouse gas emission and increase soil fertility. However, the effect of biochar application on processes occurring in the bulk soil vs that in the rhizosphere is poorly understood. This study investigated the effects of manure pellet and woodchip biochars, as compared to that of unpyrolyzed (raw) manure pellet and woodchip, on plant grain yield, and soil respiration in the bulk and rhizosphere soils in a greenhouse experiment using the rhizobox technique. The raw manure pellet and woodchip and their biochars were applied to the soil at the rate of 57 t ha-1 and spring wheat (Triticum aestivum L. var. GP168) was grown in the rhizosphere compartment of the rhizobox. Soil amendment with raw manure pellet and its biochar significantly increased plant grain yield by 36.3 and 16.1%, as compared to the control (without amendment), while raw woodchip and its biochar applications significantly decreased plant grain yield. Manure pellet and woodchip biochars significantly reduced soil respiration from the rhizosphere by 24.6 and 29.7%, respectively, relative to the control, but not that from the bulk soil (P > 0.05). Relativized cumulative CO2 emission was significantly reduced by both manure pellet and woodchip biochars from rhizosphere and bulk soils. Dissolved organic carbon and nitrogen were increased (P < 0.01) in all soil amendment treatments in both bulk and rhizosphere soils, but microbial biomass carbon and nitrogen in the rhizosphere soil were reduced by manure pellet biochar application. We conclude that biochars produced from organic residues have differential impacts on processes in bulk and rhizosphere soils, and thus measurements based on bulk soil alone may result in erroneous conclusions about the effect of biochars on soil CO2 emission.


Assuntos
Carvão Vegetal/análise , Fertilizantes/análise , Eliminação de Resíduos , Solo/química , Triticum/crescimento & desenvolvimento , Triticum/metabolismo , Biomassa , Grão Comestível/crescimento & desenvolvimento , Compostos Orgânicos/metabolismo , Microbiologia do Solo
18.
Ecotoxicol Environ Saf ; 179: 71-78, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31026752

RESUMO

Bioconcentration factors and median lethal concentrations (LC50s) are important when assessing risks posed by organic pollutants to aquatic ecosystems. Various quantitative structure-activity relationship models have been developed to predict bioconcentration factors and classify acute toxicity. In the study, we developed a regression model using Recursive Feature Elimination (RFE) method combined with the Support Vector Machine (SVM) algorithm. We calculated 2D molecular descriptors from a dataset containing 450 diverse chemicals in our regression model. Then we built three ensemble models using three machine learning algorithms and calculated 12 molecular fingerprints from a dataset containing 400 diverse chemicals in our classification models. In the regression model, the R2 and Rpred2 for the regression model were 0.860 and 0.757, respectively. Other parameters indicated that the regression model made good predictions and could efficiently predict a new set of compounds following standards set by Golbraikh, Tropsha, and Roy. In the classification models, the ensemble-SVM classification model gave an overall accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve of 92.2, 95.1, 86.0, and 0.965, respectively, in a five-fold cross-validation and of 87.3, 92.6, 76.0, and 0.940, respectively, in an external validation. These parameters indicated that our ensemble-SVM model was more stable and gave more accurate predictions than previous models. The model could therefore be used to effectively predict aquatic toxicity and assess risks posed to aquatic ecosystems. We identified several structures most relevant to acute aquatic toxicity through predictions made by the two types of models, and this information may be important to aquatic toxicology experiments and aquatic system management.


Assuntos
Organismos Aquáticos , Compostos Orgânicos/toxicidade , Poluentes Químicos da Água/toxicidade , Algoritmos , Organismos Aquáticos/efeitos dos fármacos , Organismos Aquáticos/metabolismo , Aprendizado de Máquina , Compostos Orgânicos/química , Compostos Orgânicos/metabolismo , Relação Quantitativa Estrutura-Atividade , Máquina de Vetores de Suporte , Poluentes Químicos da Água/química , Poluentes Químicos da Água/metabolismo
19.
Poult Sci ; 98(10): 4716-4721, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30993341

RESUMO

The objective of this study was to evaluate the effect of different trace mineral supplementation sources in the diet of broiler breeders on their performance and on their progenies. In total, 128 Cobb 500 broiler breeders were distributed according to a completely randomized experimental design in 2 experimental treatments. The control group was fed a diet supplemented with inorganic trace minerals (ITM), while the other group was fed a diet supplemented with reduced levels of trace minerals in the organic form. Eggs were collected when breeders were 35, 47, and 53 wk old. Their progeny (450 hatchlings) were divided according to trace mineral supplementation source from the maternal diet, creating 2 treatments with 16 replicates of 15 birds each. Organic trace mineral (OTM) supplementation improved broiler breeder performance, as shown by higher egg production and better eggshell quality of OTM-fed hens compared with those fed ITM. Egg fertility and hatchability were not influenced by the treatments. As to progeny performance, higher weight gain, and consequently, better feed conversion ratio, were obtained in the 41-day-old progenies of OTM-fed breeders, independently of hen age. Maternal diet trace mineral source did not affect broiler carcass, breast meat, or leg yields. The results of the present study show that supplementing broiler breeder diets with organic trace mineral sources enhances the performance of breeders and their progenies.


Assuntos
Galinhas/fisiologia , Suplementos Nutricionais/análise , Minerais/metabolismo , Oligoelementos/metabolismo , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Dieta/veterinária , Feminino , Compostos Inorgânicos/administração & dosagem , Compostos Inorgânicos/metabolismo , Minerais/administração & dosagem , Compostos Orgânicos/administração & dosagem , Compostos Orgânicos/metabolismo , Oligoelementos/administração & dosagem
20.
Nat Chem ; 11(5): 402-418, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30988417

RESUMO

Small molecule effectors are essential for drug discovery. Specific molecular recognition, reversible binding and dose-dependency are usually key requirements to ensure utility of a novel chemical entity. However, artefactual frequent-hitter and assay interference compounds may divert lead optimization and screening programmes towards attrition-prone chemical matter. Colloidal aggregates are the prime source of false positive readouts, either through protein sequestration or protein-scaffold mimicry. Nevertheless, assessment of colloidal aggregation remains somewhat overlooked and under-appreciated. In this Review, we discuss the impact of aggregation in drug discovery by analysing select examples from the literature and publicly-available datasets. We also examine and comment on technologies used to experimentally identify these potentially problematic entities. We focus on evidence-based computational filters and machine learning algorithms that may be swiftly deployed to flag chemical matter and mitigate the impact of aggregates in discovery programmes. We highlight the tools that can be used to scrutinize libraries, and identify and eliminate these problematic compounds.


Assuntos
Coloides/metabolismo , Descoberta de Drogas , Aprendizado de Máquina , Compostos Orgânicos/metabolismo , Proteínas/metabolismo , Coloides/química , Compostos Orgânicos/química , Ligação Proteica , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/metabolismo
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