Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 5.153
Filtrar
1.
World J Microbiol Biotechnol ; 35(8): 129, 2019 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-31376017

RESUMO

Metal whole-cell biosensors (WCBs) have been reported as very useful tools to detect and quantify the presence of bioavailable fractions of certain metals in water and soil samples. In the current work, two bacterial WCBs able to report Cr(VI) presence and plants growing on Cr(VI)-enriched soil/medium were used to assess the potential transfer of this metal to organisms of higher trophic levels, and the risk of transfer to the food chain. To do it, the functionality of the WCBs within tissues of inoculated plants in contact with Cr(VI)-contaminated soil and water was studied in vitro and in a controlled greenhouse environment. One WCB was the previously described Ochrobactrum tritici pCHRGFP2 and the second, Nitrospirillum amazonense pCHRGFP2, is a newly engineered naturally-occurring endophytic microorganism. Three rice varieties (IAC 4440, BRS 6 CHUÍ, IRGA 425) and one maize variety (1060) were tested as hosts and subjected to Cr(VI) treatments (25 µM), with different results obtained. Inoculation of each WCB into plants exposed to Cr(VI) showed GFP expression within plant tissues. WCBs penetrated the root tissues and later colonized the shoots and leaves. In general, a higher fluorescence signal was detected in roots, together with a higher Cr content and denser WCB colonization. Best fluorescence intensities per plant biomass of shoots were obtained for plant host IRGA 425. Therefore, by analyzing colonized tissues, both WCBs allowed the detection of Cr(VI) contamination in soils and its transfer to plants commonly used in crops for human diet.


Assuntos
Técnicas Biossensoriais/métodos , Cromo/análise , Ochrobactrum/crescimento & desenvolvimento , Oryza/química , Rhodospirillaceae/crescimento & desenvolvimento , Zea mays/química , Disponibilidade Biológica , Engenharia Metabólica , Microscopia de Fluorescência , Ochrobactrum/genética , Ochrobactrum/metabolismo , Oryza/crescimento & desenvolvimento , Oryza/microbiologia , Rhodospirillaceae/genética , Rhodospirillaceae/metabolismo , Poluentes do Solo/análise , Poluentes Químicos da Água/análise , Zea mays/crescimento & desenvolvimento , Zea mays/microbiologia
2.
J Agric Food Chem ; 67(35): 9789-9795, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31373816

RESUMO

Pulmonary fibrosis is a chronic lung disease characterized by abnormal accumulation of the extracellular matrix (ECM). Chronic damage of the alveolar epithelium leads to a process called "epithelial-mesenchymal transition" (EMT) and increases synthesis and deposition of ECM proteins. Therefore, inhibition of EMT might be a promising therapeutic approach for the treatment of pulmonary fibrosis. ß-Sitosterol is one of the most abundant phytosterols in the plant kingdom and the major constituent in corn silk, which is derived from the stigma and style of maize (Zea mays). In this study, we elucidated that ß-sitosterol inhibited transforming growth factor-ß1 (TGF-ß1)-induced EMT and consequently had an antifibrotic effect. ß-Sitosterol (1-10 µg/mL) significantly downregulated the TGF-ß1-induced fibrotic proteins, such as collagen, fibronectin, and α-smooth muscle actin in human alveolar epithelial cells (p < 0.01). After 24 h, relative wound density (RWD) was increased in TGF-ß1 treated group (82.16 ± 5.70) compare to the control group (64.63 ± 2.21), but RWD was decreased in ß-sitosterol cotreated group (10 µg/mL: 71.54 ± 7.39; 20 µg/mL: 65.69 ± 6.42). In addition, the changes of the TGF-ß1-induced morphological shape and protein expression of EMT markers, N-cadherin, vimentin, and E-cadherin, were significantly blocked by ß-sitosterol treatment (p < 0.01). The effects of ß-sitosterol on EMT were found to be associated with the TGF-ß1/Snail pathway, which is regulated by Smad and non-Smad signaling pathways. Taken together, these findings suggest that ß-sitosterol can be used to attenuate pulmonary fibrosis through suppression of EMT by inhibiting the TGF-ß1/Snail pathway.


Assuntos
Células Epiteliais Alveolares/efeitos dos fármacos , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Extratos Vegetais/farmacologia , Alvéolos Pulmonares/efeitos dos fármacos , Fibrose Pulmonar/fisiopatologia , Sitosteroides/farmacologia , Zea mays/química , Actinas/genética , Actinas/metabolismo , Células Epiteliais Alveolares/citologia , Células Epiteliais Alveolares/metabolismo , Caderinas/genética , Caderinas/metabolismo , Linhagem Celular , Fibronectinas/genética , Fibronectinas/metabolismo , Humanos , Extratos Vegetais/química , Alvéolos Pulmonares/metabolismo , Alvéolos Pulmonares/fisiopatologia , Fibrose Pulmonar/tratamento farmacológico , Fibrose Pulmonar/genética , Fibrose Pulmonar/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/metabolismo
3.
J Agric Food Chem ; 67(35): 9858-9867, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31389230

RESUMO

Farnesene is an important chemical platform for many industrial products, such as biofuels and polymers. We performed high-efficiency utilization of corncobs for ß-farnesene production by separate hydrolysis and fermentation with an optimized Escherichia coli strain. First, we developed a recycling strategy for both corncob pretreatment and cellulose hydrolysis, which saved great amounts of pretreatment reagents and presented a 96.83% cellulose conversion rate into glucose. However, the corncob hydrolysate strongly repressed cell growth and ß-farnesene production, being caused by high-concentrated citrate. Through expressing a heterologous ATP citrate lyase and screening for a suitable expression host, an optimized strain was constructed that produced ß-farnesene at 4.06 g/L after 48 h in a 5 L fermenter, representing an approximately 2.3-fold increase over the initial strain. Therefore, the proposed strategy about the recycling process and repression elimination was successful and suitable for the production of lignocellulosic-based ß-farnesene, which can be further studied to scale up for industrialization.


Assuntos
Escherichia coli/genética , Escherichia coli/metabolismo , Lignina/metabolismo , Sesquiterpenos/metabolismo , Fermentação , Glucose/metabolismo , Hidrólise , Engenharia Metabólica , Reciclagem , Resíduos/análise , Zea mays/química , Zea mays/microbiologia
4.
J Agric Food Chem ; 67(35): 9772-9781, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31398019

RESUMO

This study aims to investigate the response profiles of vitamin E and carotenoids on transcription and metabolic levels of sweet corn seedlings under temperature stress. The treated temperatures were set as 10 °C (low temperature, LT), 25 °C (control, CK), and 40 °C (high temperature, HT) for sweet corn seedlings. The gene expression profiles of vitamin E and carotenoids biosynthesis pathways were analyzed by real time quantitative polymerase chain reaction (RT-qPCR), and the composition profiles were analyzed by high performance liquid chromatography (HPLC). Results showed that vitamin E gradually accumulated in response to LT stress but was limited by HT stress. The increase of carotenoids was suppressed by LT stress whereas HT stress promoted it. The existing results elaborated the interactive and competitive relationships of vitamin E and carotenoids in sweet corn seedlings to respond to extreme temperature stress at transcriptional and metabolic levels. The present study would improve sweet corn temperature resilience with integrative knowledge in the future.


Assuntos
Carotenoides/metabolismo , Vitamina E/metabolismo , Zea mays/metabolismo , Carotenoides/análise , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plântula/química , Plântula/genética , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Estresse Fisiológico , Temperatura Ambiente , Vitamina E/análise , Zea mays/química , Zea mays/genética , Zea mays/crescimento & desenvolvimento
5.
Bioresour Technol ; 291: 121855, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31357042

RESUMO

The aim of the present work was to compare corn stalk (CS) and cow manure (CM) for hydrochar production at different reaction temperatures (180-260 °C) and retention times (1-4 h). CM and CS resulted in hydrochars with significantly different physicochemical properties; however, both led to similar yields (30-65%). CM-derived hydrochar had a lower carbon content but a higher nitrogen and ash content than CS-derived hydrochar. CM-derived hydrochar demonstrated potential as a soil amendment due to its higher content of nitrogen, the presence of surface functional groups and higher specific surface area in comparison to CS-derived hydrochar. In comparison, CS-derived hydrochar demonstrated suitability as a solid fuel due to its high heating value and low ignition temperature. This study revealed that the composition of lignocellulose significantly impacted the properties and thus potential applications of hydrochar.


Assuntos
Carvão Vegetal/metabolismo , Esterco , Zea mays/química , Animais , Carbono/química , Carbono/metabolismo , Bovinos , Nitrogênio/metabolismo , Solo
6.
Plant Foods Hum Nutr ; 74(3): 391-398, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31256321

RESUMO

A maize milling by-product was defatted by aqueous extraction and the residue was dehydrated, comminuted and sieved to obtain two powders differing in particle size and having a very high fibre content. The powders were then incorporated into the structure of short-dough biscuit, at two wheat flour substitution levels (10 and 20%), aiming at the development of a nutritionally improved product. Their impact on biscuit dough properties and the quality and sensory characteristics of the final products was evaluated. As it was revealed, powders' addition altered dough consistency and alveograph indices mainly due to interactions between wheat flour proteins and polysaccharides and enhanced the nutritional profile of the biscuits by inducing a 4- to 6-fold increase of their fibre content. Additionally, it influenced only to a limited extent the degree of some of the final product characteristics, e.g., protein and fat content, spread ratio, breaking strength, depending both on the level of incorporation and the particle size of the residue. On the whole, products' sensory quality was not negatively influenced, suggesting that it is possible to use both powders for the fortification with fibre of biscuits and possibly other bakery products.


Assuntos
Fibras na Dieta/análise , Alimentos Fortificados , Triticum/química , Zea mays/química , Pão/análise , Farinha/análise , Pós , Paladar , Água/química
7.
Plant Foods Hum Nutr ; 74(3): 446-447, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31273640

RESUMO

Cookies are one of the most consumed bakery products and the formulation could be modified to consider them as a functional food. The high amylose maize starch (HAMS) is considered as resistant starch (RS) type 2. The objective of this work was to assess the starch fractions, texture, sensory properties and acceptability of wheat flour cookies added with HAMS at different percentages. Adding 15% of HAMS into the formulation increased the amount of RS from 2.3 to 12.8%. In sensory analysis, children and adults showed a good acceptability of cookies since the addition of HAMS did not result in significant changes in flavor or color. Cookies made with HAMS could be considered as functional foods since they had an acceptable texture and low caloric content.


Assuntos
Amilose/química , Compostos Fitoquímicos/análise , Amido/química , Triticum/química , Zea mays/química , Adulto , Criança , Digestão , Farinha/análise , Alimento Funcional , Humanos , Paladar
8.
Food Chem ; 298: 125044, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260971

RESUMO

Fumonisin B1 (FB1) is a carcinogenic mycotoxin produced by Fusarium species contaminating maize. At present, fumonisin determination is performed using costly and demanding chromatography techniques or immunoassays. Recently, a molecularly imprinted polymer nanoparticles (nanoMIPs) - based assay (MINA) has been developed for FB1 detection. Herein, we have applied MINA for the determination of FB1 in naturally contaminated maize samples and results were compared with those obtained with ELISA and a reference HPLC method (AOAC No. 2001.04). The nanoMIPs as a recognition element mimicking antibodies used in ELISA were produced by solid phase synthesis and used in MINA for FB1 determination in 53 maize samples. As a result, 18 maize samples were contaminated with FB1 at levels higher than 0.25 mg/kg. Fumonisin concentrations from samples measured by MINA were well correlated with those using ELISA and HPLC. Therefore, MINA could be used as an alternative technique for FB1 determination in maize.


Assuntos
Ensaio de Imunoadsorção Enzimática/métodos , Fumonisinas/análise , Impressão Molecular , Nanopartículas/química , Polímeros/química , Zea mays/química , Cromatografia Líquida de Alta Pressão , Zea mays/metabolismo
9.
Sci Total Environ ; 690: 502-510, 2019 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-31301491

RESUMO

Copper oxide nanoparticles (CuO NPs), as an antimicrobial nanomaterial, have found many applications in agriculture. Ubiquitous and complex root exudates (RE) in the plant root zone motivates the determination of how specific components of RE interact with CuO NPs. This work aims to reveal the role of maize (Zea mays L.)-derived RE and their components on the aggregation and dissolution of CuO NPs in the rhizosphere. We observed that RE significantly inhibited the aggregation of CuO NPs regardless of ionic strength and electrolyte type. In the presence of RE, the CCC of CuO NPs in NaCl shifted from 30 to 125 mM and the value in CaCl2 shifted from 4 to 20 mM. Furthermore, this inhibition was correlated with molecular weight (MW) of RE fractions. Higher MW fraction (>10 kDa) reduced the aggregation most. We also discovered that RE significantly promoted the dissolution of CuO NPs and lower MW fraction (<3 kDa) RE mainly contributed to this process. Additionally, phytotoxicity of CuO NPs in the presence of RE and different fractions of RE was evaluated. The addition of 20 mg/L RE reduced the seedlings growth rate to 1.89% after 7 days exposure to 25 mg/L CuO NPs, which were significantly lower than the control group (4.82%). Notably, Cu accumulation in plant root tissues was significantly enhanced by 20 mg/L RE. This study provides useful insights into the interactions between RE and CuO NPs, which is of significance for the safe use of CuO NPs-based antimicrobial products in agricultural production.


Assuntos
Nanopartículas/química , Exsudatos de Plantas/química , Zea mays/química , Cobre , Nanopartículas/toxicidade , Concentração Osmolar , Exsudatos de Plantas/toxicidade , Raízes de Plantas/química , Rizosfera , Zea mays/toxicidade
10.
Anal Chim Acta ; 1078: 142-150, 2019 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-31358212

RESUMO

Mycotoxins and pesticides are prevalent in cereal food. It is difficult to detect these two kinds of hazard factors simultaneously in rapid assay. In order to find a solution to the problem, carbamates and aflatoxins were selected in this study to establish a rapid, on-site, and quantitative paper sensor. Two novel monoclonal antibodies (mAbs) against carbaryl and carbofuran (1D2 and G11) were developed. The IC50 values (half maximal inhibitory concentration) were 0.8 ng/mL and 217.6 ng/mL for carbaryl and carbofuran, respectively. Based on the sensitive and specific mAbs, a multi-TRFICA (time-resolved fluorescence) paper sensor was developed, which simultaneously detected six types of hazardous chemicals, including AFB1, AFB2, AFG1, AFG2, carbaryl, and carbofuran. A universal sample pretreatment method for mycotoxins and pesticides was explored to apply on established competitive indirect enzyme-linked immunosorbent assay (icELISA) and multi-TRFICA-paper sensor. The established paper sensor can be easily observed with naked eyes, qualitatively under a UV lamp, and quantitated using a home-made device. It exhibited a calculated limit of quantity for AFTs, carbaryl, and carbofuran of 0.03, 0.02, and 60.2 ng/mL in corn samples, respectively. The spiking-recoveries and real sample studies proved that multi-TRFICA-paper sensor is an accurate, sensitive, and high throughput detection method for simple and low-cost analysis in corn samples.


Assuntos
Aflatoxinas/análise , Ensaio de Imunoadsorção Enzimática/métodos , Papel , Resíduos de Praguicidas/análise , Anticorpos Monoclonais/imunologia , Carbaril/imunologia , Carbofurano/imunologia , Európio/química , Fluorescência , Contaminação de Alimentos/análise , Nanopartículas Metálicas/química , Zea mays/química
11.
Food Chem ; 300: 125176, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31351258

RESUMO

Mycotoxins are toxic metabolites produced by fungi or molds, which may cause serious harm to human health through polluted cereal foods. In order to measure the typical mycotoxin contaminations in wheat and corn, a surface plasmon resonance (SPR) method was established using SPR sensor chip that was fabricated based on self-assembled monolayer. The minimum detection limit of aflatoxin B1, ochratoxin A, zearalenone and deoxynivalenol were identified as 0.59 ng/mL, 1.27 ng/mL, 7.07 ng/mL and 3.26 ng/mL, respectively. The cross-reactivity for all four mycotoxins were demonstrated to be low. Moreover, the test data were compared with HPLC-MS/MS confirmatory analysis results and good agreement was found between them. In conclusion, the SPR method for simultaneously detecting four mycotoxins has been developed with high sensitivity, good linearity and specificity, which can meet the detection requirements of cereal foods.


Assuntos
Micotoxinas/análise , Ressonância de Plasmônio de Superfície/métodos , Triticum/química , Zea mays/química , Aflatoxina B1/análise , Aflatoxina B1/imunologia , Cromatografia Líquida de Alta Pressão , Reações Cruzadas , Análise de Alimentos/instrumentação , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Hidrazonas/química , Limite de Detecção , Micotoxinas/imunologia , Ocratoxinas/análise , Ocratoxinas/imunologia , Sensibilidade e Especificidade , Ressonância de Plasmônio de Superfície/instrumentação , Espectrometria de Massas em Tandem , Tricotecenos/análise , Tricotecenos/imunologia , Triticum/microbiologia , Zea mays/microbiologia , Zearalenona/análise , Zearalenona/imunologia
12.
Carbohydr Polym ; 219: 290-297, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31151528

RESUMO

Microbial contamination has evolved as a life-threatening problem afflicting people due to various diseases caused by pathogenic bacteria in drinking water. Thus developing novel antibacterial materials is an urgent need. Herein, a chitosan (CTS)/ biochar-nanosilver (C-Ag) antibacterial composite was prepared by a method of CTS-coated on C-Ag obtained through a facile high-temperature carbonization process using corn straw as the carbon substrate. The results from FT-IR, XRD, SEM and TG-DSC revealed that the biochar loading spherical silver nanoparticles was coated with CTS in the composite. The antibacterial activity of the CTS/C-Ag composite was investigated using the plate counting method with Escherichia coli (E. coli), and the results suggest that the composite exhibited excellent antibacterial activity against E. coli. In this application study, it was proven that the CTS/C-Ag composite exhibits sustainable antibacterial activity and good reusability for drinking water. Therefore, the CTS/C-Ag composite has potential application in drinking water treatment.


Assuntos
Antibacterianos , Quitosana/farmacologia , Água Potável , Escherichia coli/efeitos dos fármacos , Nanocompostos/química , Purificação da Água/métodos , Antibacterianos/química , Antibacterianos/farmacologia , Carvão Vegetal/química , Quitosana/química , Água Potável/análise , Água Potável/microbiologia , Nanopartículas Metálicas/química , Extratos Vegetais/química , Prata/química , Zea mays/química
13.
Carbohydr Polym ; 219: 39-45, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31151539

RESUMO

An aqueous dispersion of alpha-lipoic acid (ALA) using octenylsuccinic anhydride-modified high-amylose starch (OS) was prepared, and thermal stability and cellular bioavailability of ALA were compared with those prepared using native high-amylose starch (HA) and beta-cyclodextrin (ß-CD). The ALA was homogeneously dispersed via the encapsulation of V-type amylose helices. In comparison with HA and ß-CD, OS exhibited a higher ALA absorption in Caco-2 cells, indicating the OS facilitated the intestinal epithelial transport of ALA. Oral administration of the encapsulated ALA in-vivo resulted in a higher maximum ALA plasma concentration and extended the terminal half-life by 30-40%. The area under the plasma concentration vs. time for the administration of ALA complexed by OS was 50% larger than that by HA, indicating the effectiveness of OS in enhancing the oral bioavailability of ALA. These results indicate that OS is an efficient carrier for ALA in oral delivery and bioavailability.


Assuntos
Amilose/química , Succinatos/química , Ácido Tióctico , Zea mays/química , beta-Ciclodextrinas/química , Administração Oral , Animais , Disponibilidade Biológica , Células CACO-2 , Meia-Vida , Humanos , Masculino , Ratos Sprague-Dawley , Ácido Tióctico/sangue , Ácido Tióctico/farmacocinética
14.
J Agric Food Chem ; 67(25): 7082-7086, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31199642

RESUMO

Vitamins are important nutrients for many fermentations, but they are generally costly. Agricultural lignocellulose biomass contains considerable amounts of vitamin B compounds, but these water-soluble vitamins are easily lost into wastewater discharge during pretreatment or detoxification of lignocellulose in biorefinery processes. Here, we showed that the dry acid pretreatment and biodetoxification process allowed the preservation of significant amounts of vitamin B, which promoted l-lactic acid fermentation efficiency significantly. Supplementation with specific vitamin B compounds, VB3 and VB5, into corn stover hydrolysate led to further increases of cellulosic l-lactic acid yield and fermentation rates. This study provided a new solution for the enhancement of biorefinery fermentation efficiency by using vitamin B compounds in lignocellulose biomass.


Assuntos
Ácido Láctico/metabolismo , Lignina/metabolismo , Pediococcus acidilactici/metabolismo , Complexo Vitamínico B/metabolismo , Fermentação , Hidrólise , Lignina/química , Pediococcus acidilactici/crescimento & desenvolvimento , Caules de Planta/química , Caules de Planta/metabolismo , Caules de Planta/microbiologia , Resíduos/análise , Zea mays/química , Zea mays/metabolismo , Zea mays/microbiologia
15.
J Agric Food Chem ; 67(25): 7050-7059, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31240932

RESUMO

This work aimed to investigate the effect of selenium (Se) and irrigation on the grain yield, on the forms of Se, phenols, and carotenes, and on some antioxidant activities of maize ( Zea mays L.) grains. To reach this goal, a 2 year experiment was undertaken. Maize was fertigated with sodium selenite at the rate of 200 g of Se ha-1 and grown under two water regimes. While the irrigation did not show a clear effect on the selected parameters, Se fertigation increased the contents of inorganic and organic Se forms, xanthophyll, and salicylic acid. Furthermore, while Se fertigation decreased the hydroxycinnamic acid content, generally higher antioxidant activities were found in Se-treated grains than in the control. These findings suggest that Se fertigation increases most of the nutraceutical values of maize grains, which therefore might improve human and livestock health and could increase the maize grain shelf life and its byproducts.


Assuntos
Antioxidantes/análise , Biofortificação/métodos , Suplementos Nutricionais/análise , Selenito de Sódio/metabolismo , Água/análise , Zea mays/química , Irrigação Agrícola , Antioxidantes/metabolismo , Alimentos Fortificados/análise , Sementes/química , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Selenito de Sódio/análise , Solo/química , Água/metabolismo , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
16.
Environ Pollut ; 249: 1002-1010, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31146306

RESUMO

One attraction of using hydrochar (HC) and biochar (BC) in soil is their intrinsic affinity for organic contaminants. Oxidative ageing is likely to induce changes in physicochemical properties and functionality. To explore the long-term potential trajectories for corn stalk HC and BC to adsorb organic pollutants, we employed HC and BC exposure in 5% H2O2 to simulate oxidative ageing and get insights into mechanisms of atrazine adsorption on fresh and artificially aged materials. The physicochemical properties of fresh and aged materials were systematically compared using elemental analysis, SSA, FTIR, XPS and SEM-EDS, alongside K2Cr2O7/H2SO4 treatment to assess chemical oxidation stability. Atrazine is a typical herbicide chemical and hydrophobic organic pollutant. Adsorption isotherms of atrazine were used to reveal differences in mechanisms of sorption to BC and HC, by assessment before and ageing. BC freshly produced at 650 °C displayed higher capacity for atrazine sorption than BC produced at 500 °C, with a dominant role for π-π EDA interactions. The sorption capacity of HC freshly produced at 250 °C was higher than for HC produced at 200 °C HC, owing to higher C content and atrazine partitioning into the organic phase. Ageing increased the surface abundance of oxygenated functional groups for BC and HC and diminished bulk aromaticity. After ageing, atrazine sorption by high temperature BC was lower, but for HC it was increased. Such divergent effects must be considered when developing strategies to co-manage contaminants and carbon through the addition of carbonized materials to land.


Assuntos
Atrazina/análise , Carvão Vegetal/química , Herbicidas/análise , Poluentes do Solo/análise , Solo/química , Adsorção , China , Temperatura Alta , Peróxido de Hidrogênio/química , Oxirredução , Caules de Planta/química , Propriedades de Superfície , Zea mays/química
17.
J Agric Food Chem ; 67(26): 7466-7474, 2019 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-31184886

RESUMO

The ZMM28 protein encoded by the zmm28 gene is endogenous to maize. DP202216 maize was genetically modified to increase and extend expression of the zmm28 gene relative to native zmm28 gene expression, resulting in plants with enhanced grain yield potential. Evaluation of the history of safe use (HOSU) is one component of the safety assessment framework for a newly expressed protein in a GM crop. The deduced amino acid sequence of the introduced ZMM28 protein in DP202216 maize is identical to the ZMM28 protein in nonmodified conventional maize. The ZMM28 protein has also been found in selected varieties of sweet corn kernels, and closely related proteins are found in other commonly consumed food crops. Concentrations of the ZMM28 protein in event DP202216 maize, conventional maize, and sweet corn are reported. This information supports, in part, the evaluation of HOSU, which can be leveraged in the safety assessment of the ZMM28 protein. Additional studies will be considered in the food and feed safety assessment of the DP202216 maize event.


Assuntos
Proteínas de Plantas/química , Plantas Geneticamente Modificadas/química , Zea mays/química , Sequência de Aminoácidos , Qualidade de Produtos para o Consumidor , Inocuidade dos Alimentos , Alimentos Geneticamente Modificados , Humanos , Dados de Sequência Molecular , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Alinhamento de Sequência , Zea mays/genética , Zea mays/metabolismo
18.
Food Chem ; 297: 124912, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31253263

RESUMO

An anti-idiotypic nanobody-phage display-mediated immuno-polymerase chain reaction (PD-IPCR) method was developed for simultaneous quantitative detection of total aflatoxins and zearalenone in cereals. Two phages, displaying the variable domain of the heavy chain anti-idiotypic nanobody that binds aflatoxin- or zearalenone-specific monoclonal antibody (1C11 or 2D3), were used as competitors for corresponding analytes. Specific DNA sequences encoding anti-idiotypic nanobodies were used to design the primers for PCR amplification. The results indicated that detection limits for total aflatoxins and zearalenone in a sample were 0.03 and 0.09 ng mL-1, respectively. Recoveries of spiked aflatoxins and zearalenone were 80-118% and 76.7-111%, respectively. Validation results were in good agreement with the gold-standard high-performance liquid chromatography method. This report is the first to describe PD-IPCR for simultaneous quantitative detection of total aflatoxins and zearalenone in cereals.


Assuntos
Aflatoxinas/análise , Anticorpos Anti-Idiotípicos/imunologia , Imunoensaio/métodos , Zearalenona/análise , Aflatoxinas/imunologia , Anticorpos Anti-Idiotípicos/genética , Cromatografia Líquida de Alta Pressão , Limite de Detecção , Oryza/química , Oryza/metabolismo , Biblioteca de Peptídeos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Anticorpos de Domínio Único/genética , Anticorpos de Domínio Único/imunologia , Zea mays/química , Zea mays/metabolismo , Zearalenona/imunologia
19.
Bioresour Technol ; 289: 121691, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31252318

RESUMO

Zeolites have been widely used as catalysts in the catalytic pyrolysis of biomass to produce biofuels and/or bio-based chemicals, which could lead to the replacement of fossil sources by renewable ones. However, conventional zeolites often suffer from diffusion resistance for large intermediate oxygenates. To solve this problem, a micro/mesoporous core-shell composite zeolite ZSM-5@SBA-15 was prepared and employed as a catalyst in the catalytic pyrolysis of maize straw. ZSM-5@SBA-15 was synthesized by crystallizing mesoporous silica on the external surface of ZSM-5 using the triblock copolymer Plunoric P123 as the template. The core-shell and hierarchical structures were verified using PXRD, TEM, and N2 sorption experiments. In the catalytic pyrolysis of maize straw, ZSM-5@SBA-15 significantly enhanced the yield of valuable phenols and hydrocarbons in bio-oil, compared to ZSM-5 and SBA-15. The results demonstrated the potential application of micro@mesoporous core-shell composite zeolites in the catalytic pyrolysis of biomass.


Assuntos
Hidrocarbonetos/química , Fenol/química , Dióxido de Silício/química , Zea mays/química , Zeolitas/química , Catálise , Hidrocarbonetos/metabolismo , Fenol/metabolismo , Pirólise
20.
Sci Total Environ ; 684: 402-412, 2019 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-31154213

RESUMO

The water retained inside the sludge flocs is the bottleneck for the dehydration of sewage sludge, which hindered the following treatment. In this study, corn core powder was modified (MCCP) using sodium hydroxide (NaOH) and cationic surfactant cetyltrimethylammonium bromide (CTMAB) to break the structure of extracellular polymeric substances (EPS) and cell membrane for enhancing the dewaterability of sewage sludge. The dewatering performance, the properties of the treated sludge, the composition and distribution of EPS were investigated to discuss the dewatering mechanism of sludge. Adding 20% DS (mass of dry solids in sludge) of MCCP reduced the moisture content (MC) and the specific resistance of filtration (SRF) of the sludge by 40% and 55%, respectively. Then, correlation analyses were performed between dewatering indices of sludge and sludge properties. A multiple linear regression model was established which indicated the relationship between MC and the key factors reflecting sludge dewaterability, demonstrating that larger particle size of sludge flocs and more total dissolved solids in filtrate may be propitious to reduce content of bound water in sludge.


Assuntos
Esgotos/química , Eliminação de Resíduos Líquidos/métodos , Zea mays/química , Pós
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA