|
| Status |
Public on Jun 29, 2007 |
| Title |
Redirection of metabolism for biological hydrogen production |
| Organism |
Rhodopseudomonas palustris |
| Experiment type |
Expression profiling by array
|
| Summary |
Photosynthetic microbes can produce the clean-burning fuel hydrogen using one of nature’s most plentiful resources, sunlight 1,2. Anoxygenic photosynthetic bacteria generate hydrogen and ammonia during a process known as biological nitrogen fixation. This reaction is catalyzed by the enzyme nitrogenase and consumes nitrogen gas, ATP and electrons 3. One bacterium, Rhodopseudomonas palustris, has a remarkable ability to obtain electrons from green plant-derived material 4,5 and to efficiently absorb both high and low intensity light energy to form ATP 6. Manipulating R. palustris or a similar organism to produce hydrogen commercially will require us to identify all its genes that contribute to hydrogen production and to understand how this process is regulated in cells. Here we describe mutant strains in which metabolism is redirected such that hydrogen production is uncoupled from nitrogen fixation. Our data indicate that three different single amino acid changes in the transcriptional regulator NifA each yielded strains that produced hydrogen even in the presence of the repressing nitrogen source ammonium and in the absence of specific inducing metabolic signals. We used the mutants to show that, in addition to nitrogenase genes, 18 genes outside of the nitrogenase gene cluster may contribute to hydrogen production. Some of these genes are likely involved in efficient ATP acquisition and in channeling electrons to nitrogenase for reduction of protons to molecular hydrogen. Our results demonstrate that photosynthetic bacteria can be genetically manipulated for sustained production of pure hydrogen in a variety of cultivation conditions in the absence of oxygen, nitrogen or other gases as long as light and an electron donor are supplied.
Keywords: Comparison of transcriptome profiles
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| Overall design |
Transcriptome profile of wild type (CGA009) growing photosynthetically in the presence of amonium an acetate was compare with that of 4 different mutants (CGA570, CGA571, CGA572 and CGA574). We did 2 biological replicates per strain.
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| Contributor(s) |
Rey FE, Heiniger EK, Harwood CS |
| Citation(s) |
17220249, 20558750, 24302724 |
| Submission date |
Jun 29, 2006 |
| Last update date |
Sep 12, 2014 |
| Contact name |
Yasuhiro Oda |
| E-mail(s) |
yasuhiro@uw.edu
|
| Organization name |
University of Washington
|
| Department |
Department of Microbiology
|
| Lab |
Harwood
|
| Street address |
Box 357242, 1705 N.E. Pacific Street, HSB K-354
|
| City |
Seattle |
| State/province |
WA |
| ZIP/Postal code |
98195-7242 |
| Country |
USA |
| |
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| Platforms (1) |
| GPL3954 |
Affymetrix Rhodopseudomonas palustris GeneChip 2 |
|
| Samples (14)
|
| GSM116886 |
R. palustris wild-type (CGA009) Replicate #1 |
| GSM116900 |
R. palustris wild-type (CGA009) Replicate #2 |
| GSM116946 |
R. palustris hydrogen-producing mutant (CGA570) Replicate #1 |
| GSM116950 |
R. palustris hydrogen-producing mutant (CGA570) Replicate #2 |
| GSM116951 |
R. palustris hydrogen-producing mutant (CGA571) Replicate #1 |
| GSM116952 |
R. palustris hydrogen-producing mutant (CGA571) Replicate #2 |
| GSM116953 |
R. palustris hydrogen producing mutant(CGA572) Replicate #1 |
| GSM116954 |
R. palustris hydrogen-producing mutant (CGA572) Replicate #2 |
| GSM116955 |
R. palustris hydrogen producing mutant (CGA574) Replicate #1 |
| GSM116956 |
R. palustris hydrogen-producing mutant (CGA574) Replicate #2 |
| GSM159274 |
R. palustris wild type (CGA009) NF Replicate #1 |
| GSM159275 |
R. palustris wild-type (CGA009) NF Replicate #2 |
| GSM159276 |
R. palustris hydrogen-producing mutant (CGA584) Replicate #1 |
| GSM159277 |
R. palustris hydrogen-producing mutant (CGA584) Replicate #2 |
|
| Relations |
| BioProject |
PRJNA96537 |
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