Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 81
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Food Chem Toxicol ; 145: 111702, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32860861

RESUMEN

Our surrounding environment, especially often-touched contaminated surfaces, plays an important role in the transmission of pathogens in society. The shortage of effective sanitizing fluids, however, became a global challenge quickly after the coronavirus disease-19 (COVID-19) outbreak in December 2019. In this study, we present the effect of surfactants on coronavirus (SARS-CoV-2) virucidal efficiency in sanitizing fluids. Sodium dodecylbenzenesulfonate (SDBS), sodium laureth sulfate (SLS), and two commercial dish soap and liquid hand soap were studied with the goal of evaporation rate reduction in sanitizing liquids to maximize surface contact time. Twelve fluids with different recipes composed of ethanol, isopropanol, SDBS, SLS, glycerin, and water of standardized hardness (WSH) were tested for their evaporation time and virucidal efficiency. Evaporation time increased by 17-63% when surfactant agents were added to the liquid. In addition, surfactant incorporation enhanced the virucidal efficiency between 15 and 27% according to the 4-field test in the EN 16615:2015 European Standard method. Most importantly, however, we found that surfactant addition provides a synergistic effect with alcohols to inactivate the SARS-CoV-2 virus. This study provides a simple, yet effective solution to improve the virucidal efficiency of commonly used sanitizers.


Asunto(s)
Antivirales/farmacología , Betacoronavirus/efectos de los fármacos , Infecciones por Coronavirus/prevención & control , Desinfectantes para las Manos/farmacología , Pandemias/prevención & control , Neumonía Viral/prevención & control , Jabones/farmacología , Tensoactivos/farmacología , 2-Propanol/farmacología , Células A549 , Bencenosulfonatos/farmacología , COVID-19 , Sinergismo Farmacológico , Etanol/farmacología , Glicerol/farmacología , Humanos , SARS-CoV-2 , Dodecil Sulfato de Sodio/análogos & derivados , Dodecil Sulfato de Sodio/farmacología , Volatilización/efectos de los fármacos
2.
Sci Rep ; 9(1): 6610, 2019 04 29.
Artículo en Inglés | MEDLINE | ID: mdl-31036900

RESUMEN

New urease and nitrification inhibitors and polymer coatings were introduced in recent years, but their effects on N loss and plant N nutrition were scarcely examined in agronomic no-tillage production systems. A field experiment of urea treated with efficiency enhancers was conducted on no-tillage corn (Zea mays L.) in Tennessee, the USA during 2013-2015. A field experiment on urea and ammonium nitrate (UAN) treated with efficiency enhancers was carried out on no-tillage corn in Tennessee in 2014 and 2015. Urea treated with N-(n-butyl) thiophosphoric triamide (NBPT) at concentrations of 20% (NBPT1), 26.7% (NBPT2), or 30% (NBPT3) and polymer coated urea (PCU) were effective but maleic-itaconic copolymer treated urea was ineffective in reducing ammonia volatilization loss and improving N nutrition, grain yield, and N agronomic use efficiency of corn compared with untreated urea. Specifically, NBPT1, NBPT2, or NBPT3 treated urea and PCU reduced the total ammonia volatilization loss by 29.1-78.8%, 35.4-81.9%, 77.3-87.4%, and 59.1-83.3% during the 20 days after N applications, but increased grain yield by 15.6-31.4%, 12.9-34.8%, 18.7-19.9%, and 14.6-41.1%, respectively. The inhibitory effect of NBPT on ammonia volatilization did not improve with NBPT concentration increased from 20% to 30%. UAN treated with NBPT3 or a combination of urease and nitrification inhibitors resulted in 16.5-16.6% higher corn yield than untreated UAN only when they were surface applied. In conclusion, when urea-containing fertilizers are surface applied without any incorporation into the soil under no-tillage, their use efficiencies and performances on corn can be enhanced with an effective urease inhibitor in areas and years with noticeable urea N losses.


Asunto(s)
Fertilizantes , Nitrógeno/metabolismo , Urea/química , Volatilización/efectos de los fármacos , Zea mays/metabolismo , Agricultura , Amoníaco/metabolismo , Dióxido de Carbono/química , Dióxido de Carbono/metabolismo , Nitrificación/efectos de los fármacos , Óxido Nitroso , Compuestos Organofosforados/química , Compuestos Organofosforados/farmacología , Polímeros/química , Suelo/química , Urea/farmacología , Ureasa/antagonistas & inhibidores , Zea mays/efectos de los fármacos , Zea mays/crecimiento & desarrollo
3.
J Anim Sci ; 95(11): 5124-5136, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29293728

RESUMEN

Effects of a tannic acid blend (ByPro; Silvateam USA, Ontario, CA) added to steam-flaked corn-based fishing diets on beef cattle growth performance, carcass characteristics, nutrient digestibility, fecal N volatilization, and meat lipid oxidation were evaluated. Steers ( = 144; 349 ± 25 kg initial BW) were blocked by initial BW and assigned randomly to 1 of 3 treatments with 12 pens/treatment and 4 steers/pen and fed ad libitum. Treatments included a control (CON; no ByPro) and ByPro fed at 30 or 60 g DM/steer daily (30-ByPro and 60-ByPro, respectively). Pen fecal samples were collected 7 d after cattle were shipped to slaughter for estimation of N volatilization. Strip loins were aged for 21 d for evaluation of color and antioxidant activity. Intake quadratically increased ( = 0.05) from d 0 to 35, whereas linear trends were observed for increased DMI from d 0 to 105 and d 0 to slaughter ( = 0.07 and = 0.06, respectively), resulting in a 3.7% greater overall DMI for 60-ByPro than for CON. No differences were detected for carcass-adjusted ADG ( = 0.65) or G:F ( = 0.17). Carcass characteristics including HCW ( = 0.52), fat thickness ( = 0.32), LM area ( = 0.57), quality grade ( = 0.44), yield grade ( = 0.29), and percentage of condemned livers ( = 0.13) were not affected by treatments. Apparent total tract digestibility of starch linearly decreased tendency ( = 0.03) with increasing ByPro dose, whereas tends for a linear decrease ( = 0.09) in CP and a quadratic increase ( = 0.09) in OM digestibility were observed. No effects of treatment ( ≥ 0.39) were noted for fecal N volatilization. An increase ( < 0.01) in metmyoglobin in strip loin steaks was observed with ByPro inclusion. Oxymyoglobin decreased ( < 0.01) as display day progressed, except on d 5, at which time CON and 30-ByPro steaks had lower proportions than 60-ByPro steaks. Only subtle changes in discoloration ratio and deoxymyoglobin were observed, whereas no effects ( ≥ 0.43) for pH or thiobarbituric acid reactive substances were noted. Feeding ByPro increased DMI during the first half of the feeding period without negatively affecting gain efficiency; however, fecal N retention was not altered by ByPro. ByPro did not negatively affect meat quality or carcass characteristics, and it did not seem to affect retail meat antioxidant activity.


Asunto(s)
Bovinos/fisiología , Lípidos/química , Nitrógeno/química , Carne Roja/análisis , Taninos/farmacología , Alimentación Animal/análisis , Animales , Bovinos/crecimiento & desarrollo , Dieta/veterinaria , Digestión/efectos de los fármacos , Heces/química , Tracto Gastrointestinal/efectos de los fármacos , Masculino , Oxidación-Reducción , Almidón/metabolismo , Vapor , Volatilización/efectos de los fármacos , Zea mays/química
6.
J Hazard Mater ; 287: 142-50, 2015 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-25655421

RESUMEN

This work investigated effects of a popular oil dispersant (Corexit EC9500A) on UV- or sunlight-mediated photodegradation of pyrene (a model polycyclic aromatic hydrocarbon) in seawater. The presence of 18 and 180mg/L of the dispersant increased the first-order photodegradation rate by 5.5% and 16.7%, respectively, and reduced or ceased pyrene volatilization. By combining individual first-order rate laws for volatilization and photodegradation, we proposed an integrated kinetic model that can adequately predict the overall dissipation of pyrene from seawater. Mechanistic studies indicated that superoxide radicals played a predominant role in pyrene photodegradation, and the dispersant enhanced formation of superoxide radicals. 1-Hydroxypyrene was the main intermediate regardless of the dispersant, suggesting that electrons were transferred from excited pyrene to oxygen. In the presence of 18mg/L of the dispersant, the photodegradation rate increased with increasing ionic strength and temperature, but decreased with increasing HA concentration, and remained independent of solution pH. The results are important in understanding roles of oil dispersants on environmental fate of persistent oil components in natural and engineered systems.


Asunto(s)
Mezclas Complejas/química , Fotólisis/efectos de los fármacos , Glicoles de Propileno/química , Pirenos/química , Ácidos Sulfónicos/química , Tensoactivos/química , Sustancias Húmicas , Concentración de Iones de Hidrógeno , Concentración Osmolar , Especies Reactivas de Oxígeno/química , Agua de Mar/química , Espectrofotometría Ultravioleta , Temperatura , Rayos Ultravioleta , Volatilización/efectos de los fármacos
7.
Bioresour Technol ; 179: 452-459, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25575204

RESUMEN

The lipase obtained from Aspergillums niger was applied to promote the hydrolysis of food waste for achieving high biomethane production. Two strategies of lipase additions were investigated. One (Group A) was to pre-treat food waste to pre-decompose lipid to fatty acids before anaerobic digestion, and another one (Group B) was to add lipase to anaerobic digester directly to degrade lipid inside digester. The lipase was used at the concentrations of 0.1%, 0.5%, and 1.0% (w/v). The results showed that Group A achieved higher biomethane production, TS and VS reductions than those of Group B. At 0.5% lipase concentration, Group A obtained experimental biomethane yield of 500.1 mL/g VS(added), 4.97-26.50% higher than that of Group B. The maximum Bd of 73.8% was also achieved in Group A. Therefore, lipase pre-treatment strategy is recommended. This might provide one of alternatives for efficient biomethane production from food waste and mitigating environmental impact associated.


Asunto(s)
Alimentos , Lipasa/farmacología , Metano/biosíntesis , Residuos , Anaerobiosis/efectos de los fármacos , Animales , Aspergillus niger/enzimología , Biodegradación Ambiental/efectos de los fármacos , China , Ácidos Grasos Volátiles/análisis , Hidrólisis/efectos de los fármacos , Modelos Teóricos , Sus scrofa , Volatilización/efectos de los fármacos
8.
Bioresour Technol ; 179: 227-233, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25545092

RESUMEN

The pyrolysis of karanj fruit hulls (KFH) and karanj fruit hull hydrothermal carbonization (KFH-HTC) hydrochar was thermogravimetrically investigated under a nitrogen environment at 5 °C/min, 10 °C/min, and 20 °C/min. The pyrolysis decomposition of KFH biomass was faster than that of KFH-HTC hydrochar because of the high volatility and fixed carbon of KFH biomass. Weight loss percentage was also affected by the heating rates. The kinetic data were evaluated with the Kissinger-Akahira-Sunose and Flynn-Wall-Ozawa methods. The activation energy values obtained with these two methods were 61.06 and 68.53 kJ/mol for KFH biomass and 130.49 and 135.87 kJ/mol for KFH-HTC hydrochar, respectively. The analysis of kinetic process mechanisms was verified with the Coats-Redfern method. KFH-HTC hydrochar may play a potential role in transforming biomass to energy-rich feedstock for thermochemical applications because of its high heating value, high fixed carbon, and low ash and sulfur contents.


Asunto(s)
Carbono/química , Frutas/química , Calor , Pongamia/química , Termogravimetría/métodos , Biomasa , Carbón Orgánico , Cinética , Pongamia/efectos de los fármacos , Volatilización/efectos de los fármacos , Agua/farmacología
9.
Environ Sci Technol ; 48(17): 10337-44, 2014 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-25122054

RESUMEN

Even though arsenic is one of the most widespread environmental carcinogens, methods of remediation are still limited. In this report we demonstrate that a strain of Pseudomonas putida KT2440 endowed with chromosomal expression of the arsM gene encoding the As(III) S-adenosylmethionine (SAM) methyltransfase from Rhodopseudomonas palustris to remove arsenic from contaminated soil. We genetically engineered the P. putida KT2440 with stable expression of an arsM-gfp fusion gene (GE P. putida), which was inserted into the bacterial chromosome. GE P. putida showed high arsenic methylation and volatilization activity. When exposed to 25 µM arsenite or arsenate overnight, most inorganic arsenic was methylated to the less toxic methylated arsenicals methylarsenate (MAs(V)), dimethylarsenate (DMAs(V)) and trimethylarsine oxide (TMAs(V)O). Of total added arsenic, the species were about 62 ± 2.2% DMAs(V), 25 ± 1.4% MAs(V) and 10 ± 1.2% TMAs(V)O. Volatilized arsenicals were trapped, and the predominant species were dimethylarsine (Me2AsH) (21 ± 1.0%) and trimethylarsine (TMAs(III)) (10 ± 1.2%). At later times, more DMAs(V) and volatile species were produced. Volatilization of Me2AsH and TMAs(III) from contaminated soil is thus possible with this genetically engineered bacterium and could be instrumental as an agent for reducing the inorganic arsenic content of soil and agricultural products.


Asunto(s)
Arsénico/metabolismo , Contaminación Ambiental/análisis , Genes Bacterianos , Ingeniería Genética , Metiltransferasas/genética , Pseudomonas putida/genética , Contaminantes del Suelo/metabolismo , Arsénico/toxicidad , Arsenicales/metabolismo , Biodegradación Ambiental/efectos de los fármacos , Cromosomas Bacterianos/genética , Fluorescencia , Metilación/efectos de los fármacos , Pseudomonas putida/efectos de los fármacos , Rhodopseudomonas/enzimología , Suelo/química , Volatilización/efectos de los fármacos
10.
Int J Biol Macromol ; 68: 205-8, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24820151

RESUMEN

Dandelion polysaccharides (DPs) have antibacterial and antioxidant activities. In this study, investigated were the effects of the DPs on preservation of white shrimp (Penaeus vannamei) during refrigerated storage. Shrimp samples were untreated or soaked in the DPs solution, and then they were stored under refrigerated conditions. Samples were taken periodically and evaluated for total viable count, pH value, total volatile basic nitrogen, and overall acceptability score. Treatment of the DPs effectively retarded bacterial growth and pH increasing, reduced total volatile basic nitrogen, and increased overall acceptability score of white shrimp (P. vannamei) during refrigerated storage. The results show that the DPs treatment could prolong shelf life for up to 10 days.


Asunto(s)
Penaeidae/citología , Polisacáridos/farmacología , Taraxacum/química , Animales , Recuento de Células , Supervivencia Celular/efectos de los fármacos , Color , Criopreservación , Concentración de Iones de Hidrógeno/efectos de los fármacos , Nitrógeno/análisis , Penaeidae/efectos de los fármacos , Volatilización/efectos de los fármacos
11.
Bioresour Technol ; 164: 78-85, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24841574

RESUMEN

Recently, anaerobic digestion of lignocellulosic biomass for methane production has attracted considerable attention. However, there is little information regarding methane production from asparagus stem, a typical lignocellulosic biomass, by anaerobic digestion. In this study, alkaline pretreatment of asparagus stem was investigated for its ability to increase hydrolysis rate and methane production and to improve biodegradability (BD). The hydrolysis rate increased with increasing NaOH dose, due to higher removal rates of lignin and hemicelluloses. However, the optimal NaOH dose was 6% (w/w) according to the specific methane production (SMP). Under this condition, the SMP and the technical digestion time of the NaOH-treated asparagus stem were 242.3 mL/g VS and 18 days, which were 38.4% higher and 51.4% shorter than those of the untreated sample, respectively. The BD was improved from 40.1% to 55.4%. These results indicate that alkaline pretreatment could be an efficient method for increasing methane production from asparagus stem.


Asunto(s)
Asparagus/química , Biomasa , Lignina/metabolismo , Metano/biosíntesis , Tallos de la Planta/química , Hidróxido de Sodio/farmacología , Anaerobiosis/efectos de los fármacos , Biodegradación Ambiental/efectos de los fármacos , Análisis de la Demanda Biológica de Oxígeno , Carbono/análisis , Concentración de Iones de Hidrógeno , Hidrólisis/efectos de los fármacos , Nitrógeno/análisis , Tallos de la Planta/efectos de los fármacos , Volatilización/efectos de los fármacos
12.
Bioresour Technol ; 164: 371-9, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24865326

RESUMEN

This study assesses the impact of organic loading rate on biohydrogen production from glucose in an up-flow anaerobic packed bed reactor (UAnPBR). Two mesophilic UAPBRs (UAnPBR1 and 2) were tested at organic loading rates (OLRs) ranging from 6.5 to 51.4 g COD L(-1)d(-1). To overcome biomass washout, design modifications were made in the UAnPBR2 to include a settling zone to capture the detached biomass. The design modifications in UAnPBR2 increased the average hydrogen yield from 0.98 to 2.0 mol-H2 mol(-1)-glucose at an OLR of 25.7 g COD L(-1)d(-1). Although, a maximum hydrogen production rate of 23.4 ± 0.9 L H2 L(-1)d(-1) was achieved in the UAnPBR2 at an OLR of 51.4 g COD L(-1)d(-1), the hydrogen yield dropped by 50% to around 1 mol-H2 mol(-1)-glucose. The microbiological analysis (PCR/DGGE) showed that the biohydrogen production was due to the presence of the hydrogen and volatile acid producers such as Clostridium beijerinckii, Clostridium butyricum, Megasphaera elsdenii and Propionispira arboris.


Asunto(s)
Biocombustibles , Reactores Biológicos , Biotecnología/instrumentación , Biotecnología/métodos , Hidrógeno/metabolismo , Compuestos Orgánicos/farmacología , Reología , Anaerobiosis/efectos de los fármacos , Bacterias/genética , Análisis de la Demanda Biológica de Oxígeno , Biomasa , Reactores Biológicos/microbiología , Electroforesis en Gel de Gradiente Desnaturalizante , Fermentación/efectos de los fármacos , Datos de Secuencia Molecular , Filogenia , ARN Ribosómico 16S/genética , Solubilidad , Factores de Tiempo , Volatilización/efectos de los fármacos
13.
Bioresour Technol ; 159: 297-304, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24657762

RESUMEN

Anaerobic digestion of waste activated sludge usually requires pretreatment procedure to improve the bioavailability of sludge, which involves considerable energy and high expenditures. This study proposes a cost-effective method for enhanced anaerobic digestion of sludge without a pretreatment by directly adding iron into the digester. The results showed that addition of Fe(0) powder could enhance 14.46% methane yield, and Fe scrap (clean scrap) could further enhance methane yield (improving rate 21.28%) because the scrap has better mass transfer efficiency with sludge and liquid than Fe(0) powder. The scrap of Fe with rust (rusty scrap) could induce microbial Fe(III) reduction, which resulted in achieving the highest methane yield (improving rate 29.51%), and the reduction rate of volatile suspended solids (VSS) was also highest (48.27%) among Fe powder, clean scrap and rusty scrap. PCR-DGGE proved that the addition of rusty scrap could enhance diversity of acetobacteria and enrich iron-reducing bacteria to enhance degradation of complex substrates.


Asunto(s)
Hierro/farmacología , Aguas del Alcantarillado/microbiología , Aguas Residuales/microbiología , Purificación del Agua/métodos , Anaerobiosis/efectos de los fármacos , Bacterias/efectos de los fármacos , Bacterias/genética , Bacterias/metabolismo , Dióxido de Carbono/metabolismo , Electroforesis en Gel de Gradiente Desnaturalizante , Ácidos Grasos Volátiles/metabolismo , Genes Bacterianos , Iones , Metano/biosíntesis , ARN Ribosómico 16S/genética , Volatilización/efectos de los fármacos
14.
Bioresour Technol ; 154: 10-7, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24370950

RESUMEN

The depolymerization of renewable lignin for phenolic monomer, a versatile biochemical and precursor for biofuel, has attracted increasing attention. Here, an efficient base-catalyzed depolymerization process for this natural aromatic polymer is presented with cheap industrial solid alkali MgO and biomass-derived solvent tetrahydrofuran (THF). Results showed that more than 13.2% of phenolic monomers were obtained under 250°C for 15 min, because of the excellent lignin dissolution of THF and its promotion effect on the catalytic activity of MgO. Furthermore, comparison characterization on the raw material, products and residual solid using elemental analysis, FT-IR, TG-DSC, Py-GC-MS and chemo-physical absorption and desorption demonstrated that this base-catalyzed process can inhibit char formation significantly. Whereas, the fact that thermal repolymerization of oligomer on the pore and surface of catalyst resulting in the declination of the catalytic performance is responsible for the residue formation.


Asunto(s)
Biomasa , Biotecnología/economía , Biotecnología/métodos , Furanos/farmacología , Lignina/metabolismo , Polimerizacion/efectos de los fármacos , Catálisis/efectos de los fármacos , Peso Molecular , Solventes , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Factores de Tiempo , Volatilización/efectos de los fármacos
15.
Bioresour Technol ; 152: 147-53, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24291315

RESUMEN

The effects of Na as organic bound form or as inorganic salts form on the pyrolysis products characteristics of alkali lignin were investigated by using thermogravimetric analyzer coupled with Fourier transform infrared spectrometry (TG-FTIR), tube furnace and thermo-gravimetric analyzer (TGA). Results of TG-FTIR and tube furnace indicated that the two chemical forms Na reduced the releasing peak temperature of CO and phenols leading to the peak temperature of the maximum mass loss rate shifted to low temperature zone. Furthermore, organic bound Na obviously improved the elimination of alkyl substituent leading to the yields of phenol and guaiacol increased, while inorganic Na increased the elimination of phenolic hydroxyl groups promoting the formation of ethers. It was also found the two chemical forms Na had different effects on the gasification reactivity of chars. For inorganic Na, the char conversion decreased with increasing the char forming temperature, while organic bound Na was opposite.


Asunto(s)
Biotecnología/métodos , Lignina/metabolismo , Hidróxido de Sodio/farmacología , Sodio/farmacología , Temperatura , Carbono/análisis , Catálisis/efectos de los fármacos , Carbón Orgánico/química , Fenoles/metabolismo , Vapor , Volatilización/efectos de los fármacos
16.
Bioresour Technol ; 153: 87-94, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24345567

RESUMEN

Batch fermentations of waste activated sludge (WAS) at alkaline pH with different inocula were performed. Paper mill anaerobic granular sludge (PAS) and dyeing mill anaerobic sludge (DAS) were used as inocula. At pH 10 the inoculation did not increase the volatile fatty acids (VFAs) production compared to the non-inoculated samples fermented in the same conditions, and the maximal VFAs yield of non-inoculated WAS was higher than inoculated WAS. However, at pH 9 the inoculation with PAS increased the sludge hydrolysis and VFAs production was 1.7-fold higher than that in non-inoculated WAS (yield 52.40mg/g of volatile solid). Denaturing gradient gel electrophoresis analysis revealed that 3 bacterial species, identified as Proteocatella, Tepidibacter, and Clostridium, disappeared when inoculated with PAS at pH 9 or at pH⩾10. The results showed that the inoculation with PAS can be helpful to achieve a relatively high VFAs production from WAS in a moderate alkaline environment.


Asunto(s)
Álcalis/farmacología , Bacterias/metabolismo , Ácidos Grasos Volátiles/biosíntesis , Fermentación/efectos de los fármacos , Microbiota/efectos de los fármacos , Aguas del Alcantarillado/microbiología , Aguas Residuales/microbiología , Anaerobiosis/efectos de los fármacos , Bacterias/efectos de los fármacos , Biocombustibles , Análisis de la Demanda Biológica de Oxígeno , Reactores Biológicos/microbiología , Electroforesis en Gel de Gradiente Desnaturalizante , Concentración de Iones de Hidrógeno/efectos de los fármacos , Hidrólisis/efectos de los fármacos , Filogenia , Polisacáridos/análisis , Proteínas/análisis , Solubilidad , Volatilización/efectos de los fármacos
17.
Bioresour Technol ; 153: 245-53, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24368273

RESUMEN

High current density of 10.0-14.6A/m(2) and COD removal up to 96% were obtained in a microbial electrochemical cell (MEC) fed with digestate at hydraulic retention time (HRT) of 4d and 8d. Volatile fatty acids became undetectable in MEC effluent (HRT 8d), except for trivial acetate (4.16±1.86mgCOD/L). Accumulated methane only accounted for 3.42% of ΔCOD. Pyrosequencing analyses showed abundant fermenters (Kosmotoga spp.) and homoacetogens (Treponema spp.) in anolytes. In anode biofilm, propionate fermenters (Kosmotoga, and Syntrophobacter spp.), homoacetogens (Treponema spp.), and anode-respiring bacteria (ARB) (Geobacter spp. and Dysgonomonas spp.) were dominant. These results imply that syntrophic interactions among fermenters, homoacetogens and ARB would allow MECs to maintain high current density and coulombic efficiency.


Asunto(s)
Bacterias/metabolismo , Fuentes de Energía Bioeléctrica/microbiología , Electricidad , Hidrógeno/metabolismo , Interacciones Microbianas , Acetatos/farmacología , Aerobiosis/efectos de los fármacos , Bacterias/efectos de los fármacos , Bacterias/genética , Biopelículas/efectos de los fármacos , Análisis de la Demanda Biológica de Oxígeno , Electrodos , Ácidos Grasos Volátiles/análisis , Genes Bacterianos/genética , Cinética , Metano/metabolismo , Interacciones Microbianas/efectos de los fármacos , ARN Ribosómico 16S/genética , Volatilización/efectos de los fármacos , Eliminación de Residuos Líquidos
18.
Bioresour Technol ; 149: 353-8, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24128397

RESUMEN

The objective of this research was to propose and investigate the availability of digested banana stem (BS) to produce biogas. Squeezed BS with less moisture content was used for biogas production through a combination of NaOH pretreatment, solid-state fermentation, and codigestion technologies. NaOH doses were optimized according to biogas fermentation performance, and the best dose was 6% (by weight) based on the total solid (TS) of BS. Under this condition, the lignin, cellulose, and hemicellulose contents decreased from 18.36%, 32.36% and 14.6% to 17.10%, 30.07%, and 10.65%, respectively, after pretreatment. After biogas digestion, TS and volatile solid (VS) reductions of the codigestion were 48.5% and 70.4%, respectively, and the biogas and methane yields based on VS loading were 357.9 and 232.4 mL/g, which were 12.1% and 21.4%, respectively, higher than the control. Results indicated that the proposed process could be an effective method for using BS to produce biogas.


Asunto(s)
Álcalis/farmacología , Biocombustibles , Biotecnología/métodos , Estiércol , Musa/química , Tallos de la Planta/química , Anaerobiosis/efectos de los fármacos , Animales , Biodegradación Ambiental/efectos de los fármacos , Celulosa/metabolismo , Lignina/metabolismo , Metano/biosíntesis , Musa/efectos de los fármacos , Tallos de la Planta/efectos de los fármacos , Polisacáridos/metabolismo , Hidróxido de Sodio/farmacología , Volatilización/efectos de los fármacos
19.
Proc Natl Acad Sci U S A ; 110(39): 15567-72, 2013 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-24019497

RESUMEN

For almost a century, the iridescence of tropical Morpho butterfly scales has been known to originate from 3D vertical ridge structures of stacked periodic layers of cuticle separated by air gaps. Here we describe a biological pattern of surface functionality that we have found in these photonic structures. This pattern is a gradient of surface polarity of the ridge structures that runs from their polar tops to their less-polar bottoms. This finding shows a biological pattern design that could stimulate numerous technological applications ranging from photonic security tags to self-cleaning surfaces, gas separators, protective clothing, sensors, and many others. As an important first step, this biomaterial property and our knowledge of its basis has allowed us to unveil a general mechanism of selective vapor response observed in the photonic Morpho nanostructures. This mechanism of selective vapor response brings a multivariable perspective for sensing, where selectivity is achieved within a single chemically graded nanostructured sensing unit, rather than from an array of separate sensors.


Asunto(s)
Estructuras Animales/anatomía & histología , Mariposas Diurnas/anatomía & histología , Pigmentación , Estructuras Animales/efectos de los fármacos , Animales , Mariposas Diurnas/efectos de los fármacos , Simulación por Computador , Fenómenos Ópticos , Oxígeno/farmacología , Pigmentación/efectos de los fármacos , Reproducibilidad de los Resultados , Propiedades de Superficie , Volatilización/efectos de los fármacos
20.
Bioresour Technol ; 148: 261-9, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24055968

RESUMEN

To evaluate the applicability of single-stage thermophilic aerobic digestion (TAD) process treating high-strength food wastewater (FWW), TAD process was operated at four organic loading rates (OLRs) from 9.2 to 37.2 kg COD/m(3)d. The effects of OLRs on microbial community changes were also examined. The highest volumetric removal rate (13.3 kg COD/m(3)d) and the highest thermo-stable protease activity (0.95 unit/mL) were detected at OLR=18.6 kg COD/m(3)d. Denaturing gradient gel electrophoresis (DGGE) profiles and quantitative PCR (qPCR) results showed significant microbial community shifts in response to changes in OLR. In particular, DGGE and phylogenetic analysis demonstrate that the presence of Bacillus sp. (phylum of Firmicutes) was strongly correlated with efficient removal of organic particulates from high-strength food wastewater.


Asunto(s)
Bacterias/crecimiento & desarrollo , Reactores Biológicos/microbiología , Alimentos , Compuestos Orgánicos/farmacología , Temperatura , Aguas Residuales/microbiología , Purificación del Agua/métodos , Aerobiosis/efectos de los fármacos , Álcalis/química , Bacterias/efectos de los fármacos , Bacterias/enzimología , Secuencia de Bases , Biodegradación Ambiental/efectos de los fármacos , Análisis de la Demanda Biológica de Oxígeno , ADN Bacteriano/genética , Electroforesis en Gel de Gradiente Desnaturalizante , Concentración de Iones de Hidrógeno/efectos de los fármacos , Lípidos/análisis , Nitrógeno/análisis , Filogenia , Reacción en Cadena de la Polimerasa , ARN Ribosómico 16S/genética , Solubilidad/efectos de los fármacos , Volatilización/efectos de los fármacos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...