Identification of the [FeFe]-hydrogenase responsible for hydrogen generation in Thermoanaerobacterium saccharolyticum and demonstration of increased ethanol yield via hydrogenase knockout. Export

@article{citeulike:5650672, abstract = {Three putative hydrogenase enzyme systems in T. saccharolyticum were investigated at the genetic, mRNA, enzymatic, and phenotypic levels. A four gene operon containing two [FeFe]-hydrogenase genes, provisionally termed hfs (hydrogenase-Fe-S), was found to be the main enzymatic catalyst of hydrogen production. hfsB, perhaps the most interesting gene of the operon, contains a [FeFe]-hydrogenase and a PAS sensory domain, and has several conserved homologues among clostridial saccharolytic, cellulolytic, and pathogenic bacteria. A second hydrogenase gene cluster, hyd, exhibited methyl viologen-linked hydrogenase enzymatic activity, but hyd gene knockouts did not influence the hydrogen yield of cultures grown in closed system batch fermentations. This result, combined with the observation that hydB contains NAD(P)+ and FMN binding sites suggests that the hyd genes are specific to the transfer of electrons from NAD(P)H to hydrogen ions. A third gene cluster, a putative [NiFe] hydrogenase with homology to the ech genes, did not exhibit hydrogenase activity under any of the conditions tested. Deletion of the hfs and hydA genes result in a loss of detectable methyl viologen-linked hydrogenase activity. Strains carrying a deletion of the hfs genes exhibit a 95\% reduction in hydrogen and acetic acid production. A hfs(-), L-ldh(-) strain exhibited an increased ethanol yield from consumed carbohydrates, and presents a new strategy to engineer increased ethanol yields in T. saccharolyticum.}, author = {Shaw, A. Joe and Hogsett, David A. and Lynd, Lee R.}, citeulike-article-id = {5650672}, citeulike-linkout-0 = {http://dx.doi.org/10.1128/JB.00497-09}, citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/19648238}, citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=19648238}, day = {31}, doi = {10.1128/JB.00497-09}, issn = {1098-5530}, journal = {Journal of bacteriology}, keywords = {ethanol, fefe, hydrogen, hydrogenase, knockout, saccharolyticum, thermoanaerobacterium, yield}, month = {July}, posted-at = {2009-08-26 15:18:03}, priority = {2}, title = {Identification of the [FeFe]-hydrogenase responsible for hydrogen generation in Thermoanaerobacterium saccharolyticum and demonstration of increased ethanol yield via hydrogenase knockout.}, url = {http://dx.doi.org/10.1128/JB.00497-09}, year = {2009} }

TY - JOUR ID - citeulike:5650672 L3 - citeulike-article-id:5650672 N2 - Three putative hydrogenase enzyme systems in T. saccharolyticum were investigated at the genetic, mRNA, enzymatic, and phenotypic levels. A four gene operon containing two [FeFe]-hydrogenase genes, provisionally termed hfs (hydrogenase-Fe-S), was found to be the main enzymatic catalyst of hydrogen production. hfsB, perhaps the most interesting gene of the operon, contains a [FeFe]-hydrogenase and a PAS sensory domain, and has several conserved homologues among clostridial saccharolytic, cellulolytic, and pathogenic bacteria. A second hydrogenase gene cluster, hyd, exhibited methyl viologen-linked hydrogenase enzymatic activity, but hyd gene knockouts did not influence the hydrogen yield of cultures grown in closed system batch fermentations. This result, combined with the observation that hydB contains NAD(P)+ and FMN binding sites suggests that the hyd genes are specific to the transfer of electrons from NAD(P)H to hydrogen ions. A third gene cluster, a putative [NiFe] hydrogenase with homology to the ech genes, did not exhibit hydrogenase activity under any of the conditions tested. Deletion of the hfs and hydA genes result in a loss of detectable methyl viologen-linked hydrogenase activity. Strains carrying a deletion of the hfs genes exhibit a 95% reduction in hydrogen and acetic acid production. A hfs(-), L-ldh(-) strain exhibited an increased ethanol yield from consumed carbohydrates, and presents a new strategy to engineer increased ethanol yields in T. saccharolyticum. JF - Journal of bacteriology SN - 1098-5530 TI - Identification of the [FeFe]-hydrogenase responsible for hydrogen generation in Thermoanaerobacterium saccharolyticum and demonstration of increased ethanol yield via hydrogenase knockout. KW - ethanol KW - fefe KW - hydrogen KW - hydrogenase KW - knockout KW - saccharolyticum KW - thermoanaerobacterium KW - yield AU - Shaw, Joe AU - Hogsett, David AU - Lynd, Lee PY - 2009/07/31/ UR - http://dx.doi.org/10.1128/JB.00497-09 ER -