RESUMEN
Superparamagnetic Fe3O4 sub-microspheres with diameters of approximately 200 nm were prepared via a solvothermal method, and then modified with epoxychloropropane. Lipase was immobilized on the modified sub-microspheres. The immobilized lipase was used in the production of biodiesel fatty acid methyl esters (FAMEs) from acidified waste cooking oil (AWCO). The effects of the reaction conditions on the biodiesel yield were investigated using a combination of response surface methodology and three-level/three-factor Box-Behnken design (BBD). The optimum synthetic conditions, which were identified using Ridge max analysis, were as follows: immobilized lipase:AWCO mass ratio 0.02:1, fatty acid:methanol molar ratio 1:1.10, hexane:AWCO ratio 1.33:1 (mL/g), and temperature 40 °C. A 97.11% yield was obtained under these conditions. The BBD and experimental data showed that the immobilized lipase could generate biodiesel over a wide temperature range, from 0 to 40 °C. Consistently high FAME yields, in excess of 80%, were obtained when the immobilized lipase was reused in six replicate trials at 10 and 20 °C.
Asunto(s)
Biocombustibles , Enzimas Inmovilizadas/metabolismo , Compuestos Epoxi/química , Óxido Ferrosoférrico/química , Hidrocarburos Clorados/química , Lipasa/metabolismo , Microesferas , Ácidos/química , Biotecnología/métodos , Enzimas Inmovilizadas/química , Ácidos Grasos/química , Hexanos/química , Lipasa/química , Metanol/química , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , Modelos Químicos , Estructura Molecular , Aceites de Plantas/química , Reproducibilidad de los Resultados , Espectroscopía Infrarroja por Transformada de Fourier , Temperatura , Difracción de Rayos XRESUMEN
The aim of present study is to develop an efficient and low-cost method for capsaicin production isolated from capsaicinoids by macroporous resin adsorption chromatography. HZ816 resin has shown the best adsorption and desorption capacities for capsaicin among other resins. To optimize the operating parameters for separation, initial concentration, diameter-to-height ratio, mobile phase ratio, and crystallization method were investigated. When capsaicinoids solution (5 g/L) was loaded onto the column (diameter-to-height ratio = 1:12) with ethanol/1% w/w NaOH (4:6, v/v) as the mobile phase, capsaicin was purified most effectively. By using acid neutralization as the crystallization method, the purity of capsaicin improved from 90.3 to 99.5% with 82.3% yield. In conclusion, this study provides a simple and low-cost method for the industrial-scale production of high-purity capsaicin.
Asunto(s)
Capsaicina/aislamiento & purificación , Industria Química/métodos , Cromatografía Liquida , Extractos Vegetales/aislamiento & purificación , Adsorción , Capsaicina/química , Extractos Vegetales/química , Porosidad , Resinas Sintéticas/químicaRESUMEN
Degrading hydrocarbon by Streptococcus sp. BT-003 as a kind of microbe for oil recovery was analyzed in this paper. The Streptococcus sp. BT-003 showed that it could use crude oil as the sole source of carbon and produce organic acid, bio-gas and polysaccharide which were propitious to emulsify and reduce the viscosity of crude oil. After cultivating 8-14 h, the viscosity of crude oil reduced from 8000-15000 mPa . s to 50-250 mPa . s. The content of organic acid increased 8-15 times, and carbon dioxide and polysaccharide reached 55 ml/l and 8 g/l respectively. Paraffin and resin reduced by 60-95%, and light components increased obviously. Fluid rheology was better than before, the interfacial tension between the crude oil and water were reduced effectively.
Asunto(s)
Petróleo/metabolismo , Streptococcus/metabolismo , Animales , Biocombustibles/análisis , Ácidos Carboxílicos/análisis , Bovinos , Mutagénesis , Mucosa Nasal/microbiología , Parafina/análisis , Polisacáridos Bacterianos/química , Polisacáridos Bacterianos/metabolismo , Streptococcus/genética , ViscosidadRESUMEN
SIM1 and ARNT2 are two basic helix-loop-helix/PAS (Per-Arnt-Sim) transcription factors that control the differentiation of neuroendocrine lineages in the mouse hypothalamus. Heterozygous Sim1 mice also develop early onset obesity, possibly due to hypodevelopment of the hypothalamus. Although SIM1 and ARNT2 form heterodimers to direct the same molecular pathway, knowledge of this pathway is limited. To facilitate the identification of their downstream genes, we combined an inducible gene expression system in a neuronal cell line with microarray analysis to screen for their transcriptional targets. This method identified 268 potential target genes of SIM1/ARNT2 that displayed >1.7-fold induced expression. 15 of these genes were subjected to Northern analysis, and a high percentage of them were confirmed to be up-regulated. In vivo, several of these genes showed neuroendocrine hypothalamic expression correlating with that of Sim1. Furthermore, we found that expression of two of these potential targets, the Jak2 and thyroid hormone receptor beta2 genes, was lost in the neuroendocrine hypothalamus of the Sim1 mutant. The expression and predicted functions of many of these genes provide new insight into both the Sim1/Arnt2 action in neuroendocrine hypothalamus development and the molecular basis for the Sim1 haplo-insufficient obesity phenotype.