Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.26 (invertase)
 4,927 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The enzymatic conversion of sugars to hydrogen could be a promising method for alternative fuel production. Maple tree sap is a source of environmental sugar (e.g., sucrose) that has the potential to be converted into hydrogen using the enzymes invertase, glucose dehydrogenase (GDH), hydrogenase, and glucose isomerase (GI) and the cofactor NADP+/NADPH. The kinetics of hydrogen production have been studied, and optimal conditions for hydrogen production are described. At low initial sucrose concentrations, in the absence of glucose isomerase, stoichiometric yields of 1 mol of H2/mol of sucrose were achieved. At higher sucrose concentrations, the yield of hydrogen declined so that at an initial sucrose concentration of 292 mM only 7% yield of hydrogen was obtained. The reason for this low yield was studied and shown not to be caused by enzyme inactivation or a pH drop during the reaction but due to an instability of the cofactor NADP+. Although gluconic acid inhibited both NADPH production and oxidation by GDH and hydrogenase, respectively, it was not the major cause of NADP+ instability. Fructose was also shown to be converted to hydrogen if GI was present in the reaction mixture. Also, by starting with sucrose, 1. 34 mol of H2/mol of sucrose was obtained if GI was present in the reaction mixture.
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PMID:Enzymatic conversion of sucrose to hydrogen 984 53

Escherichia coli HD701, a hydrogenase-upregulated strain, has the potential for industrial-scale H2 production but is unable to metabolise sucrose, which is a major constituent of many waste materials that could be used as feedstocks for H2 production processes. A 70 kb plasmid (pUR400), which carries the genes necessary for sucrose transport into the cell and its metabolism, was conjugated into E. coli strains HD701 and FTD701 [a derivative of HD701 which has a deletion of the tatC gene of the twin arginine transport (Tat) protein system] from an E. coli K12 strain. Comparative studies on H2 evolution by FTD701 and HD701, with and without the pUR400 plasmid, were made using sucrose as substrate. The parental strains did not evolve H2, although HD701/pUR400 and FTD701/pUR400 evolved 1.27 +/- 0.09 and 1.38 +/- 0.05 ml H2 mg dry wt(-1) l culture(-1), respectively over 10 h. This work provides the choice for using a recombinant E. coli strain, which produces H2 from sucrose, as an alternative to coupling-in an upstream invertase, and hence this provides a simpler method for the bioproduction of H2 from sucrose.
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PMID:Production of H2 from sucrose by Escherichia coli strains carrying the pUR400 plasmid, which encodes invertase activity. 1567 32