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Reduced Products (reduced + products)
Selected AbstractsDoubling the catabolic reducing power (NADH) output of Escherichia coli fermentation for production of reduced productsBIOTECHNOLOGY PROGRESS, Issue 1 2010Shengde Zhou Abstract Homofermentative production of reduced products requires additional reducing power output (NADH) from glucose catabolism. Anaerobic expression of the pyruvate dehydrogenase complex (PDH, encoded by aceEF-lpd, a normal aerobic operon) is able to provide the additional NADH required for production of reduced products in Escherichia coli fermentation. The multiple promoters (pflBp(1,7)) of pyruvate formate lyase (pflB) were evaluated for anaerobic expression of the aceEF-lpd operon. Four chromosomal constructs, pflBp(1,7)-aceEF-lpd, pflBp(1,6)-aceEF-lpd, pflBp(6,7)-aceEF-lpd, and pflBp6-aceEF-lpd efficiently expressed the PDH complex in anaerobically grown cells. Doubling the reducing power output was achieved when glucose was oxidized to acetyl-CoA through glycolysis and pyruvate oxidation by the anaerobically expressed PDH complex (glucose ,2 acetyl-CoA + 4 NADH). This additional reducing power output can be used for production of reduced products in anaerobic E. coli fermentation. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010 [source] Influence of pH on the Photochemical and Electrochemical Reduction of the Dinuclear Ruthenium Complex, [(phen)2Ru(tatpp)Ru(phen)2]Cl4, in Water: Proton-Coupled Sequential and Concerted Multi-Electron ReductionCHEMISTRY - A EUROPEAN JOURNAL, Issue 15 2005Norma R. de Tacconi Prof. Abstract The dinuclear ruthenium complex [(phen)2Ru(tatpp)Ru(phen)2]4+ (P; in which phen is 1,10-phenanthroline and tatpp is 9,11,20,22-tetraaza tetrapyrido[3,2-a:2,3,-c:3,,,2,,-l:2,,,,3,,,]-pentacene) undergoes a photodriven two-electron reduction in aqueous solution, thus storing light energy as chemical potential within its structure. The mechanism of this reduction is strongly influenced by the pH, in that basic conditions favor a sequential process involving two one-electron reductions and neutral or slightly acidic conditions favor a proton-coupled, bielectronic process. In this complex, the central tatpp ligand is the site of electron storage and protonation of the central aza nitrogen atoms in the reduced products is observed as a function of the solution pH. The reduction mechanism and characterization of the rich array of products were determined by using a combination of cyclic and AC voltammetry along with UV-visible reflectance spectroelectrochemistry experiments. Both the reduction and protonation state of P could be followed as a function of pH and potential. From these data, estimates of the various reduced species' pKa values were obtained and the mechanism to form the doubly reduced, doubly protonated complex, [(phen)2Ru(H2tatpp)Ru(phen)2]4+ (H2P) at low pH (,7) could be shown to be a two-proton, two-electron process. Importantly, H2P is also formed in the photochemical reaction with sacrificial reducing agents, albeit at reduced yields relative to those at higher pH. [source] A Convenient and Environmentally Benign Method of Reducing Aryl Ketones or Aldehydes by Zinc Powder in an Aqueous Alkaline SolutionCHINESE JOURNAL OF CHEMISTRY, Issue 5 2007Chao-Zhi Zhang Abstract A convenient and environmentally benign method for reducing the carbonyl group in hydroxy- and amino- 9,10-anthracenediones, ortho (or para) acyl phenols and acyl anilines to a methylene group by zinc powder in an aqueous sodium hydroxide solution was reported. Based on theoretical calculations using the density functional theory (DFT), the mechanism of these reduction reactions was postulated. This mechanism can be applied to help predicting the reduced products of aryl ketones (or aldehydes) in an alkaline solution. [source] | ||||||||||