Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
2010-6-29
pubmed:abstractText
A medium is described on which selected Rhizobium japonicum strains express hydrogenase (H(2) uptake) activity under free-living conditions. Low concentrations of carbon substrates, decreased oxygen tension, and the quantity of combined nitrogen in the medium were major factors influencing hydrogenase expression. Hydrogenase activity was dependent upon a preincubation period in the presence of H(2) under conditions such that the cells did not exhibit nitrogenase activity. H(2) uptake rates were easily measured amperometrically in aerobically or anaerobically prepared suspensions from free-living cultures. Six R. japonicum strains that formed nodules with the ability to utilize H(2) oxidized this gas when grown in free-living cultures. In comparison six randomly chosen strains forming nodules that lost H(2) in air either showed no or low capacity to take up H(2) under free-living conditions. The reduction of triphenyltetrazolium chloride in an agar medium was used to detect strains capable of oxidizing H(2). This method has enabled us to isolate a spontaneous R. japonicum mutant strain that has lost the ability to utilize H(2). This mutant strain forms nodules that evolve H(2) but other symbiotic characteristics appear normal. This strain will be useful in evaluating the importance of the hydrogenase system in the nitrogen-fixing process of legumes.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/16592544-1169973, http://linkedlifedata.com/resource/pubmed/commentcorrection/16592544-13135413, http://linkedlifedata.com/resource/pubmed/commentcorrection/16592544-14908008, http://linkedlifedata.com/resource/pubmed/commentcorrection/16592544-411477, http://linkedlifedata.com/resource/pubmed/commentcorrection/16592544-4491197, http://linkedlifedata.com/resource/pubmed/commentcorrection/16592544-5077809, http://linkedlifedata.com/resource/pubmed/commentcorrection/16592544-5365797, http://linkedlifedata.com/resource/pubmed/commentcorrection/16592544-562660, http://linkedlifedata.com/resource/pubmed/commentcorrection/16592544-564190, http://linkedlifedata.com/resource/pubmed/commentcorrection/16592544-565672, http://linkedlifedata.com/resource/pubmed/commentcorrection/16592544-986388, http://linkedlifedata.com/resource/pubmed/commentcorrection/16592544-988784
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Jul
pubmed:issn
0027-8424
pubmed:author
pubmed:issnType
Print
pubmed:volume
75
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3258-62
pubmed:dateRevised
2010-9-15
pubmed:year
1978
pubmed:articleTitle
Expression of hydrogenase activity in free-living Rhizobium japonicum.
pubmed:affiliation
Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon 97331.
pubmed:publicationType
Journal Article