The redox-sensing protein Rex modulates ethanol production in Thermoanaerobacterium saccharolyticum.
Thermoanaerobacterium saccharolyticum is a thermophilic anaerobe that has been engineered to produce high amounts of ethanol, reaching ~90% theoretical yield at a titer of 70 g/L. Here we report the physiological changes that occur upon deleting the redox-sensing transcriptional regulator Rex in wil...
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2018-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC5886521?pdf=render |
| _version_ | 1818159921989943296 |
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| author | Tianyong Zheng Anthony A Lanahan Lee R Lynd Daniel G Olson |
| author_facet | Tianyong Zheng Anthony A Lanahan Lee R Lynd Daniel G Olson |
| author_sort | Tianyong Zheng |
| collection | DOAJ |
| description | Thermoanaerobacterium saccharolyticum is a thermophilic anaerobe that has been engineered to produce high amounts of ethanol, reaching ~90% theoretical yield at a titer of 70 g/L. Here we report the physiological changes that occur upon deleting the redox-sensing transcriptional regulator Rex in wild type T. saccharolyticum: a single deletion of rex resulted in a two-fold increase in ethanol yield (from 40% to 91% theoretical yield), but the resulting strains grew only about a third as fast as the wild type strain. Deletion of the rex gene also had the effect of increasing expression of alcohol dehydrogenase genes, adhE and adhA. After several serial transfers, the ethanol yield decreased from an average of 91% to 55%, and the growth rates had increased. We performed whole-genome resequencing to identify secondary mutations in the Δrex strains adapted for faster growth. In several cases, secondary mutations had appeared in the adhE gene. Furthermore, in these strains the NADH-linked alcohol dehydrogenase activity was greatly reduced. Complementation studies were done to reintroduce rex into the Δrex strains: reintroducing rex decreased ethanol yield to below wild type levels in the Δrex strain without adhE mutations, but did not change the ethanol yield in the Δrex strain where an adhE mutation occurred. |
| first_indexed | 2024-12-11T15:53:40Z |
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| id | doaj.art-d3ecd9e85bde4a38b5352b2011c61dc7 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-11T15:53:40Z |
| publishDate | 2018-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-d3ecd9e85bde4a38b5352b2011c61dc72022-12-22T00:59:31ZengPublic Library of Science (PLoS)PLoS ONE1932-62032018-01-01134e019514310.1371/journal.pone.0195143The redox-sensing protein Rex modulates ethanol production in Thermoanaerobacterium saccharolyticum.Tianyong ZhengAnthony A LanahanLee R LyndDaniel G OlsonThermoanaerobacterium saccharolyticum is a thermophilic anaerobe that has been engineered to produce high amounts of ethanol, reaching ~90% theoretical yield at a titer of 70 g/L. Here we report the physiological changes that occur upon deleting the redox-sensing transcriptional regulator Rex in wild type T. saccharolyticum: a single deletion of rex resulted in a two-fold increase in ethanol yield (from 40% to 91% theoretical yield), but the resulting strains grew only about a third as fast as the wild type strain. Deletion of the rex gene also had the effect of increasing expression of alcohol dehydrogenase genes, adhE and adhA. After several serial transfers, the ethanol yield decreased from an average of 91% to 55%, and the growth rates had increased. We performed whole-genome resequencing to identify secondary mutations in the Δrex strains adapted for faster growth. In several cases, secondary mutations had appeared in the adhE gene. Furthermore, in these strains the NADH-linked alcohol dehydrogenase activity was greatly reduced. Complementation studies were done to reintroduce rex into the Δrex strains: reintroducing rex decreased ethanol yield to below wild type levels in the Δrex strain without adhE mutations, but did not change the ethanol yield in the Δrex strain where an adhE mutation occurred.http://europepmc.org/articles/PMC5886521?pdf=render |
| spellingShingle | Tianyong Zheng Anthony A Lanahan Lee R Lynd Daniel G Olson The redox-sensing protein Rex modulates ethanol production in Thermoanaerobacterium saccharolyticum. PLoS ONE |
| title | The redox-sensing protein Rex modulates ethanol production in Thermoanaerobacterium saccharolyticum. |
| title_full | The redox-sensing protein Rex modulates ethanol production in Thermoanaerobacterium saccharolyticum. |
| title_fullStr | The redox-sensing protein Rex modulates ethanol production in Thermoanaerobacterium saccharolyticum. |
| title_full_unstemmed | The redox-sensing protein Rex modulates ethanol production in Thermoanaerobacterium saccharolyticum. |
| title_short | The redox-sensing protein Rex modulates ethanol production in Thermoanaerobacterium saccharolyticum. |
| title_sort | redox sensing protein rex modulates ethanol production in thermoanaerobacterium saccharolyticum |
| url | http://europepmc.org/articles/PMC5886521?pdf=render |
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