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1.
Food Chem ; 443: 138502, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38306909

RESUMO

The present investigation explored the antifungal effectiveness of Trachyspermum ammi essential oil (TAEO) against Aspergillus flavus, aflatoxin B1 (AFB1) contamination, and its mechanism of action using biochemical and computational approaches. The GC-MS result revealed the chemical diversity of TAEO with the highest percentage of γ-terpinene (39 %). The TAEO exhibited minimum inhibitory concentration against A. flavus growth (0.5 µL/mL) and AFB1 (0.4 µL/mL) with radical scavenging activity (IC50 = 2.13 µL/mL). The mechanism of action of TAEO was associated with the alteration in plasma membrane functioning, antioxidative defense, and carbon source catabolism. The molecular dynamic result shows the multi-regime binding of γ-terpinene with the target proteins (Nor1, Omt1, and Vbs) of AFB1 biosynthesis. Furthermore, TAEO exhibited remarkable in-situ protection of Sorghum bicolor seed samples against A. flavus and AFB1 contamination and protected the nutritional deterioration. Hence, the study recommends TAEO as a natural antifungal agent for food protection against A. flavus mediated biodeterioration.


Assuntos
Ammi , Apiaceae , Monoterpenos Cicloexânicos , Óleos Voláteis , Sorghum , Aspergillus flavus/metabolismo , Óleos Voláteis/química , Aflatoxina B1/metabolismo , Sorghum/metabolismo , Ammi/metabolismo , Antifúngicos/química , Apiaceae/metabolismo
2.
Int J Mol Sci ; 22(17)2021 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-34502220

RESUMO

Phosphorus (P) is an essential macronutrient, playing a role in developmental and metabolic processes in plants. To understand the local and systemic responses of sorghum to inorganic phosphorus (Pi) starvation and the potential of straw and ash for reutilisation in agriculture, we compared two grain (Razinieh) and sweet (Della) sorghum varieties with respect to their morpho-physiological and molecular responses. We found that Pi starvation increased the elongation of primary roots, the formation of lateral roots, and the accumulation of anthocyanin. In Razinieh, lateral roots were promoted to a higher extent, correlated with a higher expression of SbPht1 phosphate transporters. Infrared spectra of straw from mature plants raised to maturity showed two prominent bands at 1371 and 2337 cm-1, which could be assigned to P-H(H2) stretching vibration in phosphine acid and phosphinothious acid, and their derivates, whose abundance correlated with phosphate uptake of the source plant and genotype (with a higher intensity in Razinieh). The ash generated from these straws stimulated the shoot elongation and root development of the rice seedlings, especially for the material derived from Razinieh raised under Pi starvation. In conclusion, sorghum growing on marginal lands has potential as a bio-economy alternative for mineral phosphorus recycling.


Assuntos
Oryza/crescimento & desenvolvimento , Fósforo/metabolismo , Desenvolvimento Vegetal , Proteínas de Plantas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Brotos de Planta/crescimento & desenvolvimento , Sorghum/metabolismo , Regulação da Expressão Gênica de Plantas , Oryza/metabolismo , Proteínas de Transporte de Fosfato/metabolismo , Raízes de Plantas/metabolismo , Brotos de Planta/metabolismo , Sorghum/química , Estresse Fisiológico
3.
Methods Mol Biol ; 2290: 253-270, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34009595

RESUMO

Sorghum is a versatile crop cultivated since time immemorial. It fulfills the basic needs of mankind in the contest of food, feed, fodder, nutrition, and pharmaceutical uses. Now it adds one more paramount importance as a second-generation biofuel. It offers ethanol from grain, stem (sweet sorghum), and biomass (lignocellulose), and the previous one is discouraging because of food versus fuel conflict. However sorghum lignocellulosic biofuel are gaining momentum in order to conserve nature from depleting first-generation fuel. This chapter describes interdisciplinary approaches/methods involving understanding the genetics of biofuel traits, formulating suitable breeding strategies and seed enhancement techniques to achieve higher productivity in marginal lands in order to avoid food vs. fuel conflict, and finally realization of bioethanol by involving bioengineering process. Many reviews, worldwide researches, and policy papers accepted that sorghum has tremendous potential to be used as a crop of biofuel production.


Assuntos
Biocombustíveis/análise , Sorghum/química , Sorghum/metabolismo , Bioengenharia/métodos , Biomassa , Botânica , Genética , Melhoramento Vegetal/métodos , Energia Renovável/economia , Sementes/genética , Sorghum/genética , Tecnologia/métodos , Tecnologia/tendências
4.
Methods Mol Biol ; 2290: 287-316, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34009597

RESUMO

Reduction of fossil fuels at an alarming rate has attracted increasing attention to blending biofuels worldwide. India's energy demand is expected to grow at an annual rate of 4-5 times over the next couple of decades. With self-sufficiency levels in crude oil becoming a distant dream, there is growing interest to look out for alternative fuels and the biofuels are an important option for policy makers in India. In this context, this paper reviews the experiences in India in the last two decades with respect to biofuel cultivation and its impact on land use, environment, and the livelihoods of rural communities. The objective of this paper is to assess the economics of biofuel production using Sorghum and Pearl millet feedstocks in India using a Life Cycle Analysis (LCA) approach. Baseline study was conducted during the year 2013 in the Madhya Pradesh state of India covering five districts and 333 sample farmers to understand the farmers perception about the various issues related to the production of biofuels using Indian staple food crops Sorghum and Pearl millet. Empirical data from the multi-locational trials conducted during the years 2014-2015 and 2015-2016 in farmers' fields was used to conduct the LCA analysis. Sorghum and Pearl millet feedstocks which are rain-fed crops are considered for bioethanol production with different pretreatment methods. Net Energy Ratio (NER), Net Energy Balance (NEB), Net Carbon Balance (NCB), and % Carbon reduction were some of the key parameters used for analysis and the results are evaluated based on the environmental impacts through the Life Cycle Assessment at 5% blending. Findings reveal that, dilute alkali pretreatment process is most energy intensive due to consumption of alkali consumption. Whereas dilute acid pretreatment has higher conversion efficiency than the other pretreatment processes which is due to higher glucan and xylan conversion efficiencies.The study concludes that Sorghum feedstock is more energy intensive than Pearl millet feedstock due to higher water requirement and yield. Biofuels, either conventional or advanced, should not been couraged without a comprehensive outlook on the overall impact that will ultimately have on the society, environment, or on the countries' energy security. Efforts should be made toward encouragement of research and development in the field as well as in formulating a comprehensive and effective biofuel policy for India.


Assuntos
Biocombustíveis/economia , Pennisetum/metabolismo , Sorghum/metabolismo , Carbono , Pegada de Carbono/economia , Produtos Agrícolas , Meio Ambiente , Índia , Pennisetum/genética , Energia Renovável/economia , Sorghum/genética
5.
Prep Biochem Biotechnol ; 50(9): 883-896, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32425106

RESUMO

Optimization of pretreatment and saccharification of Sorghum durra stalk (Sds) was carried out. The chimeric enzyme (CtGH1-L1-CtGH5-F194A) having ß-glucosidase (CtGH1) and endo ß-1,4 glucanase activity (CtGH5-F194A) and cellobiohydrolase (CtCBH5A) from Clostridium thermocellum were used for saccharification. Chimeric enzyme will save production cost of two enzymes, individually. Stage 2 pretreatment by 1% (w/v) NaOH assisted autoclaving + 1.5% (v/v) dilute H2SO4 assisted oven heating gave lower total sugar yield (366.6 mg/g of pretreated Sds) and total glucose yield (195 mg/g of pretreated Sds) in pretreated hydrolysate with highest crystallinity index 55.6% than the other stage 2 pretreatments. Optimized parameters for saccharification of above stage 2 pretreated biomass were 3% (w/v) biomass concentration, enzyme (chimera: cellobiohydrolase) ratio, 2:3 (U/g) of biomass, total enzyme loading (350 U/g of pretreated biomass), 24 h and 30 °C. Best stage 2 pretreated Sds under optimized enzyme saccharification conditions gave maximum total reducing sugar yield 417 mg/g and glucose yield 285 mg/g pretreated biomass in hydrolysate. Best stage 2 pretreated Sds showed significantly higher cellulose, 71.3% and lower lignin, 2.0% and hemicellulose, 12.2% (w/w) content suggesting the effectiveness of method. This hydrolysate upon SHF using Saccharomyces cerevisiae under unoptimized conditions produced ethanol yield, 0.12 g/g of glucose. Abbreviation: Ct-Clostridium thermocellum, Sds-Sorghum durra stalk, TRS-Total reducing sugar, HPLC-High performance liquid chromatography, RI-Refractive index, ADL-acid insoluble lignin, GYE-Glucose yeast extract, MGYP-Malt glucose yeast extract peptone, SHF-separate hydrolysis and fermentation, OD-Optical density, PVDF-Poly vinylidene fluoride, TS-total sugar, FESEM-Field emission scanning electron microscopy, XRD-X-ray diffraction, FTIR-Fourier transform infra-red spectroscopy and CrI-Crystallinity index.


Assuntos
Biocombustíveis , Celulose 1,4-beta-Celobiosidase/metabolismo , Clostridium thermocellum/enzimologia , Saccharomyces cerevisiae/metabolismo , Sorghum/metabolismo , beta-Glucosidase/metabolismo , Biocombustíveis/análise , Etanol/análise , Etanol/metabolismo , Fermentação , Microbiologia Industrial , Proteínas Recombinantes de Fusão/metabolismo
6.
J Hazard Mater ; 393: 121555, 2020 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-32143156

RESUMO

Crude laccase potency on biodegradation and detoxification of Reactive blue 19 (RB-19) were demonstrated, along with prediction of degradation mechanisms, pathways and byproducts analysis. Trametes versicolor, cultured on pampas grass inflorescence (Cortaderia selloana), yielded the best crude laccase activity (15.36 U/g). 10 U CLE activities demonstrated a biodegradation yield (85%) in 210 min, at pH 4, 50 °C and 200 mg/L RB-19 concentrations. Evolution of a brown color that absorbed maximally at 478 nm was observed during biodegradation. Two methods were adopted for byproducts extraction, three methods for toxicity analysis and four models for kinetic parameters (Km and Vmax) determination. 2-ethylanthracene, 2-hydroxycyclohexa-2,4-dien-1-one, 2(4-methylphenyl)-ethan-1-amine, 1-[6-hydroperoxy-4,5-bis(sulfooxy)oxan-3-yl]triaza-1,2-dien-2-ium, naphthalene-2,7-disulfonic acid and N-[(5-oxooxolan-2-yl)methyl]acetamide were detected as toxic byproducts. Brown color evolution was due to 1,1,1-triethyl-3-(methoxycarbonyl)-2,2-dioxo-2λ6-diazathian-1-ium (methoxycarbonyl sulfanyl-triethylammonium hydroxide) inner salt. Increase in color density (light to dark brown) was a function of byproduct(s) biodegradation and polymerization. RB-19 and byproduct acute toxicities were decreased significantly (98% - 6.91%). Kinetic parameters Km (18.05 mg/L) and Vmax (0.31 mg/L. min-1) from the four kinetic models demonstrated higher affinity of CLE to RB-19. CLE yielded a catalytic activity (Vmax/Km =0.017 min-1) demonstrating the flexibility of CLE active site to RB-19 binding over commercial laccase.


Assuntos
Antraquinonas/metabolismo , Proteínas Fúngicas/metabolismo , Lacase/metabolismo , Polyporaceae/enzimologia , Poluentes Químicos da Água/metabolismo , Aliivibrio fischeri/efeitos dos fármacos , Animais , Antraquinonas/toxicidade , Biodegradação Ambiental , Chlorella vulgaris/efeitos dos fármacos , Daphnia/efeitos dos fármacos , Fermentação , Proteínas Fúngicas/química , Cinética , Lacase/química , Poaceae/metabolismo , Polyporaceae/metabolismo , Sorghum/metabolismo , Triticum/metabolismo , Poluentes Químicos da Água/toxicidade
7.
Bull Environ Contam Toxicol ; 104(2): 200-205, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31781814

RESUMO

Phenoxy acid 2,4-D (2,4-dichlorophenoxy acid) is one of the most commonly-used herbicide in agriculture. Biodegradation of 2,4-D can be stimulated by structurally-related plant secondary metabolites such as ferulic acid (FA). The aim of this study is to: (1) assess the potential of indigenous soil bacteria to degrade 2,4-D in the presence of FA by PCR analysis of functional tfdA genes, (2) to determine the influence of 2,4-D and FA on samples ecotoxicity using Phytotoxkit® and Microtox® biotests. The detection of tfdA genes varied depending on the enrichment of samples with FA. FA suppressed detection of the tfdA genes, 100 µM 2,4-D induced higher detection of studied amplicons, while 500 µM 2,4-D delayed their detection. The ecotoxicity response was specific and differed between plants (PE% Lepidium sativum > Sinapis alba > Sorghum saccharatum) and bacteria (PE% up to 99% for Vibrio fischeri). Our findings confirm that 2,4-D and FA had a toxic influence on the used organisms.


Assuntos
Ácido 2,4-Diclorofenoxiacético/análise , Biodegradação Ambiental , Ácidos Cumáricos/análise , Herbicidas/análise , Poluentes do Solo/análise , Ácido 2,4-Diclorofenoxiacético/metabolismo , Aliivibrio fischeri/metabolismo , Ácidos Cumáricos/metabolismo , DNA Ribossômico/química , Genes Bacterianos , Herbicidas/metabolismo , Lepidium sativum/metabolismo , Extratos Vegetais , Sinapis/metabolismo , Solo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Sorghum/metabolismo
9.
J Sci Food Agric ; 99(3): 1351-1357, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30094850

RESUMO

BACKGROUND: The development of new products with a focus on nutrition, rather than other technical aspects, is essential to improve the quality of celiac diets. Nutritional attributes of white and brown sorghum gluten-free pasta developed in a previous work were analyzed. The extent and kinetics of starch in vitro digestion, estimated glycemic index (eGI), potentially bioaccessible and dialyzable polyphenols, and antioxidant activity were evaluated and compared with commercial products. RESULTS: Sorghum flour samples were used to obtain pasta with high protein (≈170 g kg-1 ), dietary fiber (≈80 g kg-1 ), polyphenols (2.6 g GA kg-1 pasta), and antioxidant activity. This sorghum pasta showed slower starch in vitro digestion than the other gluten-free pasta, with a high level of protein hydrolysis (76%). The highest eGI was observed in a rice sample (69.8) followed by a corn-based pasta (66.4). White and brown sorghum gluten-free pasta showed 2.9 and 2.4 times, respectively, higher potentially bioaccessible polyphenol content compared to that in cooked pasta. No significant variation in antioxidant activity was found in sorghum pasta after digestion and around 48% and 36% of activity was detected in dialysate. CONCLUSION: Both types of sorghum gluten-free pasta have demonstrated their nutritional value and represent a good potential alternative to current commercial pasta. © 2018 Society of Chemical Industry.


Assuntos
Antioxidantes/metabolismo , Dieta Livre de Glúten/economia , Digestão , Sorghum/metabolismo , Amido/metabolismo , Antioxidantes/química , Culinária , Farinha/análise , Farinha/economia , Glutens/análise , Glutens/economia , Valor Nutritivo , Sorghum/química , Amido/análise
10.
Bioresour Technol ; 175: 473-9, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25459857

RESUMO

In this study, sweet sorghum stem was subjected to hydrothermal pretreatment (HTP) and alkaline post-treatment to enhance its saccharification ratio by reducing its recalcitrance. The results showed that the HTP (110-210°C, 0.5-2.0h) significantly degraded hemicelluloses, and the pretreatment at the temperature higher than 190°C led to the partial degradation of the cellulose. As compared to the sole HTP, the integrated process removed most of lignin and hemicelluloses, which incurred a higher cellulose saccharification ratio. Under an optimum condition evaluated (HTP at 170°C for 0.5h and subsequent 2% NaOH treatment), 77.5% saccharification ratio was achieved, which was 1.8, 2.0 and 5.5 times as compared to the only HTP pretreated substrates, alkaline treated substrates alone and the raw material without pretreatment, respectively. Clearly, the integrated process can be considered as a promising approach to achieve an efficient conversion of lignocellulose to fermentable glucose.


Assuntos
Antiácidos/farmacologia , Metabolismo dos Carboidratos , Celulase/metabolismo , Caules de Planta/metabolismo , Sorghum/metabolismo , Temperatura , Reatores Biológicos , Metabolismo dos Carboidratos/efeitos dos fármacos , Celulose/metabolismo , Fermentação/efeitos dos fármacos , Glucose/metabolismo , Hidrólise/efeitos dos fármacos , Lignina/metabolismo , Polissacarídeos/metabolismo , Água/farmacologia
11.
PLoS One ; 9(4): e94480, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24736641

RESUMO

The rising demand for bioethanol, the most common alternative to petroleum-derived fuel used worldwide, has encouraged a feedstock shift to non-food crops to reduce the competition for resources between food and energy production. Sweet sorghum has become one of the most promising non-food energy crops because of its high output and strong adaptive ability. However, the means by which sweet sorghum stalks can be cost-effectively utilized for ethanol fermentation in large-scale industrial production and commercialization remains unclear. In this study, we identified a novel Saccharomyces cerevisiae strain, TSH1, from the soil in which sweet sorghum stalks were stored. This strain exhibited excellent ethanol fermentative capacity and ability to withstand stressful solid-state fermentation conditions. Furthermore, we gradually scaled up from a 500-mL flask to a 127-m3 rotary-drum fermenter and eventually constructed a 550-m3 rotary-drum fermentation system to establish an efficient industrial fermentation platform based on TSH1. The batch fermentations were completed in less than 20 hours, with up to 96 tons of crushed sweet sorghum stalks in the 550-m3 fermenter reaching 88% of relative theoretical ethanol yield (RTEY). These results collectively demonstrate that ethanol solid-state fermentation technology can be a highly efficient and low-cost solution for utilizing sweet sorghum, providing a feasible and economical means of developing non-food bioethanol.


Assuntos
Etanol/metabolismo , Fermentação , Saccharomyces cerevisiae/metabolismo , Sorghum/metabolismo , Biocombustíveis/microbiologia , Análise Custo-Benefício , Saccharomyces cerevisiae/crescimento & desenvolvimento
12.
Electron. j. biotechnol ; 14(6): 3-3, Nov. 2011. ilus, tab
Artigo em Inglês | LILACS | ID: lil-640520

RESUMO

Dried spent yeast (DSY) was used as a low-cost nitrogen supplement for ethanol fermentation from sweet sorghum juice under very high gravity (VHG) conditions by Saccharomyces cerevisiae NP 01. The fermentation was carried out at 30ºC in a 5-litre bioreactor. The results showed that DSY promoted ethanol production efficiencies. The ethanol concentration (P), productivity (Qp) and yield (Yp/s) of the sterile juice (total sugar of 280 g l-1) supplemented with 8 g l-1 of DSY were not different from those supplemented with yeast extract and/or peptone at the same amount. The initial yeast cell concentration of 5 x 10(7) cells ml-1 was found to be optimal for scale-up ethanol production. In addition, an increase in sugar concentration in inoculum preparation medium (from 10 to 100 g l-1) improved the ability of the inoculum to produce ethanol under the VHG conditions. When S. cerevisiae NP 01 grown in the juice containing 100 g l-1 of total sugar was used as the inoculum for ethanol fermentation, the P, Qp and Yp/s obtained were 108.98 +/- 1.16 g l-1, 2.27 +/- 0.06 g l-1 h-1 and 0.47 +/- 0.01 g g-1, respectively. Similar results were also observed when the ethanol fermentation was scaled up to a 50-litre bioreactor under the same conditions. The cost of the sweet sorghum for ethanol production was US$ 0.63 per litre of ethanol. These results clearly indicate the high potential of using sweet sorghum juice supplemented with DSY under VHG fermentation for ethanol production in industrial applications.


Assuntos
Etanol/metabolismo , Fermentação , Hipergravidade , Nitrogênio , Saccharomyces cerevisiae/fisiologia , Sorghum/metabolismo , Leveduras
13.
Ecol Food Nutr ; 49(2): 129-41, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21883085

RESUMO

Sorghum malt and dolo quality evaluation criteria and parameters affecting quality were surveyed in six cities in Burkina Faso through questionnaires addressed to malt processors, dolo processors, retailers, and consumers. The major quality criteria for malt quality assessment were perceived to be taste and presence/absence of roots in the malt. Taste, alcohol content, and wort sufficiently cooked were perceived as major criteria for the dolo quality assessment. The major parameters affecting malt quality were perceived to be malt production period, proportions of grain and the amount of water entering malting, presence of pesticide residues in the malting grains, and age of grain. Processing method, yeast source, proportions of the components (crushed grain, water, mucilage, yeast) entering dolo production, malt quality, wort temperature at time of inoculation, amount of energy available for cooking, wort and sediment boiling time, quality of mucilage, malt with non-sweet taste, presence/absence of roots in the malt, and ease of filtering crushed malt were perceived as major parameters affecting the dolo quality. These results will be used in the improvement of the dolo supply chain in Burkina Faso by providing more reliable information for training programs for efficient dolo brewing processes, development of best cropping practices to improve grain quality, and providing better selection criteria for sorghum breeding programs.


Assuntos
Cerveja/análise , Análise de Alimentos/métodos , Sementes/química , Sorghum/química , Burkina Faso , Comportamento do Consumidor , Etanol/metabolismo , Feminino , Fermentação , Manipulação de Alimentos/métodos , Germinação , Humanos , Masculino , Resíduos de Praguicidas/análise , Raízes de Plantas/efeitos adversos , Controle de Qualidade , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Sorghum/crescimento & desenvolvimento , Sorghum/metabolismo , Inquéritos e Questionários , Paladar , Recursos Humanos
14.
Bioresour Technol ; 100(4): 1595-607, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18951018

RESUMO

Sweet sorghum has been identified as a possible ethanol feedstock because of its biomass yield and high concentration of readily fermentable sugars. It has found limited use, however, because of poor post-harvest storage characteristics and short harvest window in cooler climates. Previous research (Bennett, A.S., Anex, R.P., 2008. Farm-gate production costs of sweet sorghum as a bioethanol feedstock. Transactions of the ASABE 51(2), 603-613) indicates that fermentable carbohydrates (FC) can be produced at less expense from sweet sorghum than from corn grain. Previous research, however, did not include costs associated with off-farm transportation, storage, or capital costs associated with milling and energy recovery equipment that are required to provide FC suitable for biological conversion. This study includes these additional costs and reevaluates sweet sorghum as a biocommodity feedstock. A total of eight harvest-transport-processing options are modeled, including 4-row self-propelled and 2-row tractor-pulled forage harvesters, two different modes of in-field transport, fresh processing, on-farm ensilage and at-plant ensilage. Monte Carlo simulation and sensitivity analysis are used to account for system variability and compare scenarios. Transportation costs are found to be significant ranging from $33 to $71 Mg (-1) FC, with highest costs associated with at-plant ensilage scenarios. Economies of scale benefit larger milling equipment and boiler systems reducing FC costs by more than 50% when increasing annual plant capacity from 37.9 to 379 million liters. Ensiled storage of high moisture sweet sorghum in bunkers can lead to significant losses of FC (>20%) and result in systems with net FC costs well above those of corn-derived FC. Despite relatively high transport costs, seasonal, fresh processed sweet sorghum is found to produce FC at costs competitive with corn grain derived FC.


Assuntos
Agricultura/economia , Agricultura/métodos , Fontes de Energia Bioelétrica/economia , Etanol/síntese química , Etanol/economia , Sorghum/metabolismo , Meios de Transporte/economia , Carboidratos/química , Simulação por Computador , Fermentação , Meio-Oeste dos Estados Unidos , Método de Monte Carlo , Silagem/economia
15.
J Environ Manage ; 86(3): 535-44, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17331637

RESUMO

The use of ethylene diamine tetraacetic acid (EDTA) on the electrokinetic removal of cadmium-contaminated soil was evaluated. A total of four different tests were conducted using EDTA as a washing solution as well as a purging solution at the electrode compartments. The efficiency of electrokinetic extraction was significantly influenced by the pH of the soil medium. The results show that EDTA was effective in desorbing cadmium at a high pH, with Cd-EDTA(-) anion complexes migrating toward the anode. At low pH values near the anode area, cadmium existed as Cd(2+), migrating toward the cathode. Such contradicting directions of cadmium have resulted in its detrimental removal from the soil cell. However, accumulation of cadmium near the cathode was observed at the end of the tests due to the dominating low pH in the soil cell. The phytotoxicity after the electrokinetic process was investigated using Sorghum saccharatum, Lepidium sativum and Sinapis alba plants. The germination index was a major endpoint estimated by measuring seed germination and shoot elongation. The results obtained show that the phytotoxicity was increased after electrokinetic extraction. Despite, the extensive cadmium removal from two-thirds of the cell, the low pH of the soil was the principal parameter exhibiting the phytotoxicity.


Assuntos
Cádmio/química , Cádmio/toxicidade , Ácido Edético/química , Eletroquímica/métodos , Poluentes do Solo/análise , Adsorção , Condutividade Elétrica , Eletrodos , Concentração de Íons de Hidrogênio , Cinética , Lepidium sativum/crescimento & desenvolvimento , Lepidium sativum/metabolismo , Sinapis/crescimento & desenvolvimento , Sinapis/metabolismo , Poluentes do Solo/metabolismo , Sorghum/crescimento & desenvolvimento , Sorghum/metabolismo
16.
Bioresour Technol ; 96(9): 985-1002, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15668196

RESUMO

Reducing the use of non-renewable fossil energy reserves together with improving the environment are two important reasons that drive interest in the use of bioethanol as an automotive fuel. Conversion of sugar and starch to ethanol has been proven at an industrial scale in Brazil and the United States, respectively, and this alcohol has been able to compete with conventional gasoline due to various incentives. In this paper, we examined making ethanol from the sugar extracted from the juice of sweet sorghum and/or from the hemicellulose and cellulose in the residual sorghum bagasse versus selling the sugar from the juice or burning the bagasse to make electricity in four scenarios in the context of North China. In general terms, the production of ethanol from the hemicellulose and cellulose in bagasse was more favorable than burning it to make power, but the relative merits of making ethanol or sugar from the juice was very sensitive to the price of sugar in China. This result was confirmed by both process economics and analysis of opportunity costs. Thus, a flexible plant capable of making both sugar and fuel-ethanol from the juice is recommended. Overall, ethanol production from sorghum bagasse appears very favorable, but other agricultural residues such as corn stover and rice hulls would likely provide a more attractive feedstock for making ethanol in the medium and long term due to their extensive availability in North China and their independence from other markets. Furthermore, the process for residue conversion was based on particular design assumptions, and other technologies could enhance competitiveness while considerations such as perceived risk could impede applications.


Assuntos
Carboidratos/biossíntese , Carboidratos/economia , Fontes Geradoras de Energia/economia , Etanol/economia , Etanol/metabolismo , Sorghum/metabolismo , Reatores Biológicos/economia , Indústria Química/economia , China , Simulação por Computador , Conservação dos Recursos Naturais , Análise Custo-Benefício/métodos , Metabolismo Energético , Microbiologia Industrial/economia , Modelos Econométricos
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