Bier ist ein komplexes Stoffgemisch aus Wasser, Ethanol und einer Vielzahl von flüchtigen und nichtflüchtigen geschmacksaktiven Verbindungen. Während der Lagerung kommt es zu chemischen Reaktionen, ...bei denen einige Bestandteile abgebaut und andere neu gebildet werden. Mit dem chemischen Profil verändert sich auch der Geschmack eines Bieres, was zur Alterung und schließlich zum Verderb führen kann. Den Einfluss der Verpackung auf die Lagerstabilität hat kürzlich ein US‐amerikanisches Forscherteam untersucht.
NF-kappaB is a major inflammatory response mediator in the liver, playing a key role in the pathogenesis of alcoholic liver injury. We investigated zonal as well as liver cell type-specific ...distribution of NF-kappaB activation across the liver acinus following adaptation to chronic ethanol intake and 70% partial hepatectomy (PHx). We employed immunofluorescence staining, digital image analysis and statistical distributional analysis to quantify subcellular localization of NF-kappaB in hepatocytes and hepatic stellate cells (HSCs). We detected significant spatial heterogeneity of NF-kappaB expression and cellular localization between cytoplasm and nucleus across liver tissue. Our main aims involved investigating the zonal bias in NF-kappaB localization and determining to what extent chronic ethanol intake affects this zonal bias with in hepatocytes at baseline and post-PHx. Hepatocytes in the periportal area showed higher NF-kappaB expression than in the pericentral region in the carbohydrate-fed controls, but not in the ethanol group. However, the distribution of NF-kappaB nuclear localization in hepatocytes was shifted towards higher levels in pericentral region than in periportal area, across all treatment conditions. Chronic ethanol intake shifted the NF-kappaB distribution towards higher nuclear fraction in hepatocytes as compared to the pair-fed control group. Ethanol also stimulated higher NF-kappaB expression in a subpopulation of HSCs. In the control group, PHx elicited a shift towards higher NF-kappaB nuclear fraction in hepatocytes. However, this distribution remained unchanged in the ethanol group post-PHx. HSCs showed a lower NF-kappaB expression following PHx in both ethanol and control groups. We conclude that adaptation to chronic ethanol intake attenuates the liver zonal variation in NF-kappaB expression and limits the PHx-induced NF-kappaB activation in hepatocytes, but does not alter the NF-kappaB expression changes in HSCs in response to PHx. Our findings provide new insights as to how ethanol treatment may affect cell-type specific processes regulated by NF-kappaB activation in liver cells.
Due to increasing population and industrialization, the demand of energy is increasing day by day. Simultaneously, the worldwide bio-ethanol production is increasing constantly. The maize, sugarcane ...and sugar beets are major traditional agricultural crops used as bio-ethanol production but these crops are unable to meet the global demand of bio-ethanol production due to their primary value of food and feed. Hence, cellulosic materials such as agro-residues are attractive feedstock for bio-ethanol production. The cellulosic material is the most abundant biomass and agro-residues on the earth. Bio-ethanol from agro-residues could be a promising technology that involves four processes of pre-treatment, enzymatic hydrolysis, fermentation and distillation. These processes have several challenges and limitations such as biomass transport and handling, and efficient pre-treatment process for removing the lignin from the lignocellulosic agro-residues. Proper pre-treatment process may increase the concentrations of fermentable sugars after enzymatic hydrolysis, thereby improving the efficiency of the whole process. Others, efficient microbes and genetically modified microbes may also enhance the enzymatic hydrolysis. Conversion of cellulose to ethanol requires some new pre-treatment, enzymatic and fermentation technologies, to make the whole process cost effective. In this review, we have discussed about current technologies for sustainable bioethanol production from agro-residues.
To further improve the intrinsic reactivity of single-atom catalysts (SACs), the controllable modification of a single site by coordinating with a second neighboring metal atom, developing ...double-atom catalysts (DACs), affords new opportunities. Here we report a catalyst that features two bonded Fe–Co double atoms, which is well represented by an FeCoN6(OH) ensemble with 100% metal dispersion, that work together to switch the reaction mechanism in alcohol dehydrogenation under oxidant-free conditions. Compared with Fe-SAC and Co-SAC, FeCo-DAC displays higher activity performance, yielding the desired products in up to 98% yields. Moreover, a broad diversity of benzyl alcohols and aliphatic alcohols convert into the corresponding dehydrogenated products with excellent yields and high selectivity. The kinetic reaction results show that lower activation energy is obtained by FeCo-DAC than that by Fe-SAC and Co-SAC. Moreover, computational studies demonstrate that the reaction path by DACs is different from that by SACs, providing a rationale for the observed enhancements.
Yeast to directly convert cellulose and, especially, the microcrystalline cellulose into bioethanol, was engineered through display of minicellulosomes on the cell surface of Saccharomyces cerevisiae .... The construction and cell surface attachment of cellulosomes were accomplished with two individual miniscaffoldins to increase the display level. All of the cellulases including a celCCA (endoglucanase), a celCCE (cellobiohydrolase), and a Ccel_2454 (β-glucosidase) were cloned from Clostridium cellulolyticum , ensuring the thermal compatibility between cellulose hydrolysis and yeast fermentation. Cellulases and one of miniscaffoldins were secreted by α-factor; thus, the assembly and attachment to anchoring miniscaffoldin were accomplished extracellularly. Immunofluorescence microscopy, flow cytometric analysis (FACS), and cellulosic ethanol fermentation confirmed the successful display of such complex on the yeast surface. Enzyme–enzyme synergy, enzyme-proximity synergy, and cellulose–enzyme–cell synergy were analyzed, and the length of anchoring miniscaffoldin was optimized. The engineered S. cerevisiae was applied in fermentation of carboxymethyl cellulose (CMC), phosphoric acid-swollen cellulose (PASC), or Avicel. It showed a significant hydrolytic activity toward microcrystalline cellulose, with an ethanol titer of 1,412 mg/L. This indicates that simultaneous saccharification and fermentation of crystalline cellulose to ethanol can be accomplished by the yeast, engineered with minicellulosome.
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