{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/22186"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/22186","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Ammonia assimilation by Ruminococcus flavefaciens FD-1","abstract":"Studies were conducted to better understand the mechanism by which Ruminococcus flavefaciens FD-1 utilizes ammonia (-um). $\\sp{14}$C-methyl-ammonium was not taken up by R. flavefaciens FD-1, but cells prepared similarly depleted ammonia from media (initial rates of 11.2 and 0.8 nmol$\\cdot$min$\\sp{-1}{\\cdot}$mg$\\sp{-1}$ protein for cells grown with limiting nitrogen and carbon, respectively).","abstract_html":"Studies were conducted to better understand the mechanism by which Ruminococcus flavefaciens FD-1 utilizes ammonia (-um). $\\sp{14}$C-methyl-ammonium was not taken up by R. flavefaciens FD-1, but cells prepared similarly depleted ammonia from media (initial rates of 11.2 and 0.8 nmol$\\cdot$min$\\sp{-1}{\\cdot}$mg$\\sp{-1}$ protein for cells grown with limiting nitrogen and carbon, respectively).","abstract_has_math":true,"creators":["Duncan, Paul Alan"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Animal Sciences","degree_department":null,"school":null,"contributors":["Mackie, Roderick I."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-05-07T13:31:45Z","date_published":"2011-05-07T13:31:45Z","updated_at":"2026-07-22T22:25:19Z","subjects":["Biology, Microbiology","Agriculture, Animal Culture and Nutrition"],"languages":["eng"],"rights":["Copyright 1993 Duncan, Paul Alan"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9329020","(UMI)AAI9329020"],"render_values":[{"text":"AAI9329020","href":null,"code":true},{"text":"(UMI)AAI9329020","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/22186","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Mackie, Roderick I."]},{"key":"dc:creator","label":"Author","values":["Duncan, Paul Alan"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-07T13:31:45Z","10000-01-01","1993"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Animal Sciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Biology, Microbiology","Agriculture, Animal Culture and Nutrition"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 1993 Duncan, Paul Alan"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9329020","(UMI)AAI9329020","http://hdl.handle.net/2142/22186"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Studies were conducted to better understand the mechanism by which Ruminococcus flavefaciens FD-1 utilizes ammonia (-um). $\\sp{14}$C-methyl-ammonium was not taken up by R. flavefaciens FD-1, but cells prepared similarly depleted ammonia from media (initial rates of 11.2 and 0.8 nmol$\\cdot$min$\\sp{-1}{\\cdot}$mg$\\sp{-1}$ protein for cells grown with limiting nitrogen and carbon, respectively).","Glutamine synthetase activity was only detected using the $\\gamma$-glutamyl transferase assay. The specific activity was 10-fold higher when cells were grown in ammonia-limiting compared to carbon-limiting defined medium (574 versus 60 nmol$\\cdot$min$\\sp{-1}{\\cdot}$mg$\\sp{-1}$ for whole cell assays). Specific activity was reduced by 10-30% by sudden exposure of cells grown with ammonia-limitation to high levels of ammonia, but this loss of activity was not consistent with the adenylylation model of post-translational regulation found in the enteric bacteria.","Glutamate dehydrogenase activity was 3-fold higher in cells grown in ammonia-limiting compared to carbon-limiting defined medium. Glutamate dehydrogenase was purified 119-fold from batch grown cells. The K$\\sb{\\rm m}$'s for ammonia, $\\alpha$-ketoglutarate, and glutamate were 19.2, 0.41 and 62 mM, respectively. The sigmoidal NADPH saturation curve revealed positive cooperativity for the binding of this coenzyme. The native enzyme and subunits are 280 and 48 kDa, respectively, suggesting that the native enzyme is a hexamer. The first residue in the amino-terminal amino acid sequence from R. flavefaciens GDH was alanine, suggesting that the protein may be modified post-translationally. Comparison of the amino-terminal sequence with those of E. coli, S. typhimurium and Clostridium symbiosum revealed only 39% amino acid homologies.","A degenerate oligonucleotide probe was synthesized and used to screen a recombinant subgenomic library of R. flavefaciens FD-1 chromosomal DNA for the gene encoding glutamate dehydrogenase.","Ammonium uptake rates were 1-2 orders of magnitude lower than GS $\\gamma$GT specific activity, and 2-3 orders of magnitude lower than that of GDH. This suggests that the enzymatic incorporation of ammonia into amino acid form (or at least glutamate) is not a limiting step in ammonia assimilation.","Made available in DSpace on 2011-05-07T13:31:45Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9329020.pdf: 7469287 bytes, checksum: 8f44c104e396c8651523dc3f45a4f3b1 (MD5) Previous issue date: 1993","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:55:54Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:26:06-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"]},{"key":"dc:title","label":"Title","values":["Ammonia assimilation by Ruminococcus flavefaciens FD-1"]}]}],"canonical_facts":{"dc:contributor":["Mackie, Roderick I."],"dc:creator":["Duncan, Paul Alan"],"dc:date":["2011-05-07T13:31:45Z","10000-01-01","1993"],"dc:description":["Studies were conducted to better understand the mechanism by which Ruminococcus flavefaciens FD-1 utilizes ammonia (-um). $\\sp{14}$C-methyl-ammonium was not taken up by R. flavefaciens FD-1, but cells prepared similarly depleted ammonia from media (initial rates of 11.2 and 0.8 nmol$\\cdot$min$\\sp{-1}{\\cdot}$mg$\\sp{-1}$ protein for cells grown with limiting nitrogen and carbon, respectively).","Glutamine synthetase activity was only detected using the $\\gamma$-glutamyl transferase assay. The specific activity was 10-fold higher when cells were grown in ammonia-limiting compared to carbon-limiting defined medium (574 versus 60 nmol$\\cdot$min$\\sp{-1}{\\cdot}$mg$\\sp{-1}$ for whole cell assays). Specific activity was reduced by 10-30% by sudden exposure of cells grown with ammonia-limitation to high levels of ammonia, but this loss of activity was not consistent with the adenylylation model of post-translational regulation found in the enteric bacteria.","Glutamate dehydrogenase activity was 3-fold higher in cells grown in ammonia-limiting compared to carbon-limiting defined medium. Glutamate dehydrogenase was purified 119-fold from batch grown cells. The K$\\sb{\\rm m}$'s for ammonia, $\\alpha$-ketoglutarate, and glutamate were 19.2, 0.41 and 62 mM, respectively. The sigmoidal NADPH saturation curve revealed positive cooperativity for the binding of this coenzyme. The native enzyme and subunits are 280 and 48 kDa, respectively, suggesting that the native enzyme is a hexamer. The first residue in the amino-terminal amino acid sequence from R. flavefaciens GDH was alanine, suggesting that the protein may be modified post-translationally. Comparison of the amino-terminal sequence with those of E. coli, S. typhimurium and Clostridium symbiosum revealed only 39% amino acid homologies.","A degenerate oligonucleotide probe was synthesized and used to screen a recombinant subgenomic library of R. flavefaciens FD-1 chromosomal DNA for the gene encoding glutamate dehydrogenase.","Ammonium uptake rates were 1-2 orders of magnitude lower than GS $\\gamma$GT specific activity, and 2-3 orders of magnitude lower than that of GDH. This suggests that the enzymatic incorporation of ammonia into amino acid form (or at least glutamate) is not a limiting step in ammonia assimilation.","Made available in DSpace on 2011-05-07T13:31:45Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9329020.pdf: 7469287 bytes, checksum: 8f44c104e396c8651523dc3f45a4f3b1 (MD5) Previous issue date: 1993","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:55:54Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:26:06-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"],"dc:identifier":["AAI9329020","(UMI)AAI9329020","http://hdl.handle.net/2142/22186"],"dc:language":["eng"],"dc:rights":["Copyright 1993 Duncan, Paul Alan"],"dc:subject":["Biology, Microbiology","Agriculture, Animal Culture and Nutrition"],"dc:title":["Ammonia assimilation by Ruminococcus flavefaciens FD-1"],"dc:type":["text"],"thesis:degree_discipline":["Animal Sciences"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:19Z"}