Molecular Genetics of the Hydrogen Uptake System of Rhizobium Leguminosarum

1991 ◽  
pp. 222-225
Author(s):  
T. Ruiz-Argüeso ◽  
E. Hidalgo ◽  
J. Murillo ◽  
L. Rey ◽  
J. M. Palacios
Keyword(s):  
Molecular Genetics ◽  
Rhizobium Leguminosarum ◽  
Hydrogen Uptake ◽  
Uptake System

scholarly journals Genetic organization of the hydrogen uptake (hup) cluster from Rhizobium leguminosarum.

1990 ◽  
Vol 172 (3) ◽  
pp. 1647-1655 ◽  
Author(s):  
A Leyva ◽  
J M Palacios ◽  
J Murillo ◽  
T Ruiz-Argüeso
Keyword(s):  
Rhizobium Leguminosarum ◽  
Hydrogen Uptake ◽  
Genetic Organization

scholarly journals dpp Genes of Rhizobium leguminosarum Specify Uptake of δ-Aminolevulinic Acid

2002 ◽  
Vol 15 (1) ◽  
pp. 69-74 ◽  
Author(s):  
R. A. Carter ◽  
K. H. Yeoman ◽  
A. Klein ◽  
A. H. F. Hosie ◽  
G. Sawers ◽  
...  
Keyword(s):  
Rhizobium Leguminosarum ◽  
Aminolevulinic Acid ◽  
Inverted Repeats ◽  
Uptake System ◽  
Heme Synthesis

An operon with homology to the dppABCDF genes required to transport dipeptides in bacteria was identified in the N2-fixing symbiont, Rhizobium leguminosarum. As in other bacteria, dpp mutants were severely affected in the import of δ-aminolevulinic acid (ALA), a heme precursor. ALA uptake was antagonized by adding dipeptides, indicating that these two classes of molecule share the same transporter. Mutations in dppABCDF did not affect symbiotic N2 fixation on peas, suggesting that the ALA needed for heme synthesis is not supplied by the plant or that another uptake system functions in the bacteroids. The dppABCDF operon of R. leguminosarum resembles that in other bacteria, with a gap between dppA and dppB containing inverted repeats that may stabilize mRNA and may explain why transcription of dppA alone was higher than that of dppBCDF. The dppABCDF promoter was mapped and is most likely recognized by σ70.

scholarly journals Nickel Availability and hupSL Activation by Heterologous Regulators Limit Symbiotic Expression of theRhizobium leguminosarum bv. Viciae Hydrogenase System in Hup− Rhizobia

2000 ◽  
Vol 66 (3) ◽  
pp. 937-942 ◽  
Author(s):  
Belén Brito ◽  
Jorge Monza ◽  
Juan Imperial ◽  
Tomás Ruiz-Argüeso ◽  
Jose Manuel Palacios
Keyword(s):  
Transcriptional Activation ◽  
Sinorhizobium Meliloti ◽  
Rhizobium Leguminosarum ◽  
Transcriptional Regulator ◽  
Hydrogen Uptake ◽  
Hydrogenase Activity ◽  
Structural Genes ◽  
Mesorhizobium Loti ◽  
Genes Expression ◽  
Relevant Factors

ABSTRACT A limited number of Rhizobium andBradyrhizobium strains possess a hydrogen uptake (Hup) system that recycles the hydrogen released from the nitrogen fixation process in legume nodules. To extend this ability to rhizobia that nodulate agronomically important crops, we investigated factors that affect the expression of a cosmid-borne Hup system from Rhizobium leguminosarum bv. viciae UPM791 in R. leguminosarumbv. viciae, Rhizobium etli, Mesorhizobium loti, and Sinorhizobium meliloti Hup− strains. After cosmid pAL618 carrying the entire hup system of strain UPM791 was introduced, all recipient strains acquired the ability to oxidize H2 in symbioses with their hosts, although the levels of hydrogenase activity were found to be strain and species dependent. The levels of hydrogenase activity were correlated with the levels of nickel-dependent processing of the hydrogenase structural polypeptides and with transcription of structural genes. Expression of the NifA-dependent hupSL promoter varied depending on the genetic background, while the hyp operon, which is controlled by the FnrN transcriptional regulator, was expressed at similar levels in all recipient strains. With the exception of theR. etli-bean symbiosis, the availability of nickel to bacteroids strongly affected hydrogenase processing and activity in the systems tested. Our results indicate that efficient transcriptional activation by heterologous regulators and processing of the hydrogenase as a function of the availability of nickel to the bacteroid are relevant factors that affect hydrogenase expression in heterologous rhizobia.

Genetic Studies on the Hydrogen-Uptake System of Rhizobium

1987 ◽  
pp. 160-162
Author(s):  
T. Ruiz-Argüeso ◽  
J. M. Palacios ◽  
A. Leyva ◽  
T. Mozo
Keyword(s):  
Hydrogen Uptake ◽  
Uptake System ◽  
Genetic Studies

scholarly journals Increased biological hydrogen production by deletion of hydrogen-uptake system in photosynthetic bacteria

2009 ◽  
Vol 164 (6) ◽  
pp. 674-679 ◽  
Author(s):  
Yi Liang ◽  
Xiaobing Wu ◽  
Lihui Gan ◽  
Huijuan Xu ◽  
Zhong Hu ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Photosynthetic Bacteria ◽  
Hydrogen Uptake ◽  
Uptake System ◽  
Biological Hydrogen Production

Anaerobic nitrate-dependent chemolithotrophic growth by Rhizobium japonicum

1983 ◽  
Vol 29 (3) ◽  
pp. 316-320 ◽  
Author(s):  
John L. Neal ◽  
George C. Allen ◽  
Ronald D. Morse ◽  
Dale D. Wolf
Keyword(s):  
Nitrous Oxide ◽  
Electron Acceptor ◽  
Nitrate Reduction ◽  
Hydrogen Uptake ◽  
Growth Conditions ◽  
Rhizobium Japonicum ◽  
Uptake System ◽  
Anaerobic Conditions ◽  
Positive Strain ◽  
Chemolithotrophic Growth

A hydrogen-uptake-positive strain of Rhizobium japonicum (6-3I1b6) was demonstrated to grow in absence of oxygen chemolithotrophically, utilizing nitrate as the electron acceptor. Dissimilatory nitrate reduction occurred during growth, as evidenced by the disappearance of nitrate from the medium and production of nitrous oxide. Rhizobium japonicum 120-3I1b120, a hydrogen-uptake-negative strain, showed little or no growth under anaerobic chemolithotrophic growth conditions and did not evolve nitrous oxide. A nitrate-dependent hydrogen-uptake and an oxygen-dependent hydrogen-uptake system was present in cells of strain 6-3I1b6 grown chemolithotrophically under anaerobic conditions with nitrate serving as the electron acceptor.

scholarly journals Engineering the Rhizobium leguminosarum bv. viciae Hydrogenase System for Expression in Free-Living Microaerobic Cells and Increased Symbiotic Hydrogenase Activity

2002 ◽  
Vol 68 (5) ◽  
pp. 2461-2467 ◽  
Author(s):  
B. Brito ◽  
J. M. Palacios ◽  
J. Imperial ◽  
T. Ruiz-Argüeso
Keyword(s):  
Time Course ◽  
Rhizobium Leguminosarum ◽  
Active Form ◽  
Hydrogen Uptake ◽  
Immunoblot Analysis ◽  
Living Cells ◽  
Culture Conditions ◽  
Hydrogenase Activity ◽  
Free Living ◽  
Cell Fractions

ABSTRACT Rhizobium leguminosarum bv. viciae UPM791 induces hydrogenase activity in pea (Pisum sativum L.) bacteroids but not in free-living cells. The symbiotic induction of hydrogenase structural genes (hupSL) is mediated by NifA, the general regulator of the nitrogen fixation process. So far, no culture conditions have been found to induce NifA-dependent promoters in vegetative cells of this bacterium. This hampers the study of the R. leguminosarum hydrogenase system. We have replaced the native NifA-dependent hupSL promoter with the FnrN-dependent fixN promoter, generating strain SPF25, which expresses the hup system in microaerobic free-living cells. SPF25 reaches levels of hydrogenase activity in microaerobiosis similar to those induced in UPM791 bacteroids. A sixfold increase in hydrogenase activity was detected in merodiploid strain SPF25(pALPF1). A time course induction of hydrogenase activity in microaerobic free-living cells of SPF25(pALPF1) shows that hydrogenase activity is detected after 3 h of microaerobic incubation. Maximal hydrogen uptake activity was observed after 10 h of microaerobiosis. Immunoblot analysis of microaerobically induced SPF25(pALPF1) cell fractions indicated that the HupL active form is located in the membrane, whereas the unprocessed protein remains in the soluble fraction. Symbiotic hydrogenase activity of strain SPF25 was not impaired by the promoter replacement. Moreover, bacteroids from pea plants grown in low-nickel concentrations induced higher levels of hydrogenase activity than the wild-type strain and were able to recycle all hydrogen evolved by nodules. This constitutes a new strategy to improve hydrogenase activity in symbiosis.

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