Carbohydrate metabolism and carbon fixation in Roseobacter denitrificans OCh114.
The Roseobacter clade of aerobic marine proteobacteria, which compose 10-25% of the total marine bacterial community, has been reported to fix CO(2), although it has not been determined what pathway is involved. In this study, we report the first metabolic studies on carbohydrate utilization, CO(2)...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2009-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC2749216?pdf=render |
| _version_ | 1819099002292928512 |
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| author | Kuo-Hsiang Tang Xueyang Feng Yinjie J Tang Robert E Blankenship |
| author_facet | Kuo-Hsiang Tang Xueyang Feng Yinjie J Tang Robert E Blankenship |
| author_sort | Kuo-Hsiang Tang |
| collection | DOAJ |
| description | The Roseobacter clade of aerobic marine proteobacteria, which compose 10-25% of the total marine bacterial community, has been reported to fix CO(2), although it has not been determined what pathway is involved. In this study, we report the first metabolic studies on carbohydrate utilization, CO(2) assimilation, and amino acid biosynthesis in the phototrophic Roseobacter clade bacterium Roseobacter denitrificans OCh114. We develop a new minimal medium containing defined carbon source(s), in which the requirements of yeast extract reported previously for the growth of R. denitrificans can be replaced by vitamin B(12) (cyanocobalamin). Tracer experiments were carried out in R. denitrificans grown in a newly developed minimal medium containing isotopically labeled pyruvate, glucose or bicarbonate as a single carbon source or in combination. Through measurements of (13)C-isotopomer labeling patterns in protein-derived amino acids, gene expression profiles, and enzymatic activity assays, we report that: (1) R. denitrificans uses the anaplerotic pathways mainly via the malic enzyme to fix 10-15% of protein carbon from CO(2); (2) R. denitrificans employs the Entner-Doudoroff (ED) pathway for carbohydrate metabolism and the non-oxidative pentose phosphate pathway for the biosynthesis of histidine, ATP, and coenzymes; (3) the Embden-Meyerhof-Parnas (EMP, glycolysis) pathway is not active and the enzymatic activity of 6-phosphofructokinase (PFK) cannot be detected in R. denitrificans; and (4) isoleucine can be synthesized from both threonine-dependent (20% total flux) and citramalate-dependent (80% total flux) pathways using pyruvate as the sole carbon source. |
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| format | Article |
| id | doaj.art-bbcdd286decd477b83df652d9e13254b |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-22T00:39:57Z |
| publishDate | 2009-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-bbcdd286decd477b83df652d9e13254b2022-12-21T18:44:42ZengPublic Library of Science (PLoS)PLoS ONE1932-62032009-01-01410e723310.1371/journal.pone.0007233Carbohydrate metabolism and carbon fixation in Roseobacter denitrificans OCh114.Kuo-Hsiang TangXueyang FengYinjie J TangRobert E BlankenshipThe Roseobacter clade of aerobic marine proteobacteria, which compose 10-25% of the total marine bacterial community, has been reported to fix CO(2), although it has not been determined what pathway is involved. In this study, we report the first metabolic studies on carbohydrate utilization, CO(2) assimilation, and amino acid biosynthesis in the phototrophic Roseobacter clade bacterium Roseobacter denitrificans OCh114. We develop a new minimal medium containing defined carbon source(s), in which the requirements of yeast extract reported previously for the growth of R. denitrificans can be replaced by vitamin B(12) (cyanocobalamin). Tracer experiments were carried out in R. denitrificans grown in a newly developed minimal medium containing isotopically labeled pyruvate, glucose or bicarbonate as a single carbon source or in combination. Through measurements of (13)C-isotopomer labeling patterns in protein-derived amino acids, gene expression profiles, and enzymatic activity assays, we report that: (1) R. denitrificans uses the anaplerotic pathways mainly via the malic enzyme to fix 10-15% of protein carbon from CO(2); (2) R. denitrificans employs the Entner-Doudoroff (ED) pathway for carbohydrate metabolism and the non-oxidative pentose phosphate pathway for the biosynthesis of histidine, ATP, and coenzymes; (3) the Embden-Meyerhof-Parnas (EMP, glycolysis) pathway is not active and the enzymatic activity of 6-phosphofructokinase (PFK) cannot be detected in R. denitrificans; and (4) isoleucine can be synthesized from both threonine-dependent (20% total flux) and citramalate-dependent (80% total flux) pathways using pyruvate as the sole carbon source.http://europepmc.org/articles/PMC2749216?pdf=render |
| spellingShingle | Kuo-Hsiang Tang Xueyang Feng Yinjie J Tang Robert E Blankenship Carbohydrate metabolism and carbon fixation in Roseobacter denitrificans OCh114. PLoS ONE |
| title | Carbohydrate metabolism and carbon fixation in Roseobacter denitrificans OCh114. |
| title_full | Carbohydrate metabolism and carbon fixation in Roseobacter denitrificans OCh114. |
| title_fullStr | Carbohydrate metabolism and carbon fixation in Roseobacter denitrificans OCh114. |
| title_full_unstemmed | Carbohydrate metabolism and carbon fixation in Roseobacter denitrificans OCh114. |
| title_short | Carbohydrate metabolism and carbon fixation in Roseobacter denitrificans OCh114. |
| title_sort | carbohydrate metabolism and carbon fixation in roseobacter denitrificans och114 |
| url | http://europepmc.org/articles/PMC2749216?pdf=render |
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