Improved glycerol utilization by a triacylglycerol-producing Rhodococcus opacus strain for renewable fuels
Background: Glycerol generated during renewable fuel production processes is potentially an attractive substrate for the production of value-added materials by fermentation. An engineered strain MITXM-61 of the oleaginous bacterium Rhodococcus opacus produces large amounts of intracellular triacylg...
| Main Authors: | , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
| Published: |
Biomed Central Ltd.
2015
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| Online Access: | http://hdl.handle.net/1721.1/96820 https://orcid.org/0000-0003-1847-440X https://orcid.org/0000-0002-1015-1270 |
| _version_ | 1811086622250237952 |
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| author | Kurosawa, Kazuhiko Radek, Andreas Plassmeier, Jens K. Sinskey, Anthony J |
| author2 | Massachusetts Institute of Technology. Department of Biology |
| author_facet | Massachusetts Institute of Technology. Department of Biology Kurosawa, Kazuhiko Radek, Andreas Plassmeier, Jens K. Sinskey, Anthony J |
| author_sort | Kurosawa, Kazuhiko |
| collection | MIT |
| description | Background:
Glycerol generated during renewable fuel production processes is potentially an attractive substrate for the production of value-added materials by fermentation. An engineered strain MITXM-61 of the oleaginous bacterium Rhodococcus opacus produces large amounts of intracellular triacylglycerols (TAGs) for lipid-based biofuels on high concentrations of glucose and xylose. However, on glycerol medium, MITXM-61 does not produce TAGs and grows poorly. The aim of the present work was to construct a TAG-producing R. opacus strain capable of high-cell-density cultivation at high glycerol concentrations.
Results:
An adaptive evolution strategy was applied to improve the conversion of glycerol to TAGs in R. opacus MITXM-61. An evolved strain, MITGM-173, grown on a defined medium with 16 g L[superscript −1] glycerol, produced 2.3 g L[superscript −1] of TAGs, corresponding to 40.4% of the cell dry weight (CDW) and 0.144 g g[superscript −1] of TAG yield per glycerol consumed. MITGM-173 was able to grow on high concentrations (greater than 150 g L[superscript −1]) of glycerol. Cultivated in a medium containing an initial concentration of 20 g L[superscript −1] glycerol, 40 g L[superscript −1] glucose, and 40 g L[superscript −1] xylose, MITGM-173 was capable of simultaneously consuming the mixed substrates and yielding 13.6 g L[superscript −1] of TAGs, representing 51.2% of the CDM. In addition, when 20 g L[superscript −1] glycerol was pulse-loaded into the culture with 40 g L[superscript −1] glucose and 40 g L[superscript −1] xylose at the stationary growth phase, MITGM-173 produced 14.3 g L[superscript −1] of TAGs corresponding to 51.1% of the CDW although residual glycerol in the culture was observed. The addition of 20 g L[superscript −1] glycerol in the glucose/xylose mix resulted in a TAG yield per glycerol consumed of 0.170 g g[superscript −1] on the initial addition and 0.279 g g[superscript −1] on the pulse addition of glycerol.
Conclusion:
We have generated a TAG-producing R. opacus MITGM-173 strain that shows significantly improved glycerol utilization in comparison to the parental strain. The present study demonstrates that the evolved R. opacus strain shows significant promise for developing a cost-effective bioprocess to generate advanced renewable fuels from mixed sugar feedstocks supplemented with glycerol. |
| first_indexed | 2024-09-23T13:29:10Z |
| format | Article |
| id | mit-1721.1/96820 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T13:29:10Z |
| publishDate | 2015 |
| publisher | Biomed Central Ltd. |
| record_format | dspace |
| spelling | mit-1721.1/968202022-09-28T14:32:01Z Improved glycerol utilization by a triacylglycerol-producing Rhodococcus opacus strain for renewable fuels Kurosawa, Kazuhiko Radek, Andreas Plassmeier, Jens K. Sinskey, Anthony J Massachusetts Institute of Technology. Department of Biology Massachusetts Institute of Technology. Engineering Systems Division Kurosawa, Kazuhiko Radek, Andreas Plassmeier, Jens K. Sinskey, Anthony J. Background: Glycerol generated during renewable fuel production processes is potentially an attractive substrate for the production of value-added materials by fermentation. An engineered strain MITXM-61 of the oleaginous bacterium Rhodococcus opacus produces large amounts of intracellular triacylglycerols (TAGs) for lipid-based biofuels on high concentrations of glucose and xylose. However, on glycerol medium, MITXM-61 does not produce TAGs and grows poorly. The aim of the present work was to construct a TAG-producing R. opacus strain capable of high-cell-density cultivation at high glycerol concentrations. Results: An adaptive evolution strategy was applied to improve the conversion of glycerol to TAGs in R. opacus MITXM-61. An evolved strain, MITGM-173, grown on a defined medium with 16 g L[superscript −1] glycerol, produced 2.3 g L[superscript −1] of TAGs, corresponding to 40.4% of the cell dry weight (CDW) and 0.144 g g[superscript −1] of TAG yield per glycerol consumed. MITGM-173 was able to grow on high concentrations (greater than 150 g L[superscript −1]) of glycerol. Cultivated in a medium containing an initial concentration of 20 g L[superscript −1] glycerol, 40 g L[superscript −1] glucose, and 40 g L[superscript −1] xylose, MITGM-173 was capable of simultaneously consuming the mixed substrates and yielding 13.6 g L[superscript −1] of TAGs, representing 51.2% of the CDM. In addition, when 20 g L[superscript −1] glycerol was pulse-loaded into the culture with 40 g L[superscript −1] glucose and 40 g L[superscript −1] xylose at the stationary growth phase, MITGM-173 produced 14.3 g L[superscript −1] of TAGs corresponding to 51.1% of the CDW although residual glycerol in the culture was observed. The addition of 20 g L[superscript −1] glycerol in the glucose/xylose mix resulted in a TAG yield per glycerol consumed of 0.170 g g[superscript −1] on the initial addition and 0.279 g g[superscript −1] on the pulse addition of glycerol. Conclusion: We have generated a TAG-producing R. opacus MITGM-173 strain that shows significantly improved glycerol utilization in comparison to the parental strain. The present study demonstrates that the evolved R. opacus strain shows significant promise for developing a cost-effective bioprocess to generate advanced renewable fuels from mixed sugar feedstocks supplemented with glycerol. Sweetwater Energy, Inc. MIT Energy Initiative 2015-04-27T17:40:47Z 2015-04-27T17:40:47Z 2015-02 2014-09 Article http://purl.org/eprint/type/JournalArticle 1754-6834 http://hdl.handle.net/1721.1/96820 Kurosawa, Kazuhiko, Andreas Radek, Jens K Plassmeier, and Anthony J Sinskey. “Improved Glycerol Utilization by a Triacylglycerol-Producing Rhodococcus Opacus Strain for Renewable Fuels.” Biotechnology for Biofuels 8, no. 1 (February 26, 2015). https://orcid.org/0000-0003-1847-440X https://orcid.org/0000-0002-1015-1270 en_US http://dx.doi.org/10.1186/s13068-015-0209-z Biotechnology for Biofuels Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/ application/pdf Biomed Central Ltd. Biotechnology for Biofuels |
| spellingShingle | Kurosawa, Kazuhiko Radek, Andreas Plassmeier, Jens K. Sinskey, Anthony J Improved glycerol utilization by a triacylglycerol-producing Rhodococcus opacus strain for renewable fuels |
| title | Improved glycerol utilization by a triacylglycerol-producing Rhodococcus opacus strain for renewable fuels |
| title_full | Improved glycerol utilization by a triacylglycerol-producing Rhodococcus opacus strain for renewable fuels |
| title_fullStr | Improved glycerol utilization by a triacylglycerol-producing Rhodococcus opacus strain for renewable fuels |
| title_full_unstemmed | Improved glycerol utilization by a triacylglycerol-producing Rhodococcus opacus strain for renewable fuels |
| title_short | Improved glycerol utilization by a triacylglycerol-producing Rhodococcus opacus strain for renewable fuels |
| title_sort | improved glycerol utilization by a triacylglycerol producing rhodococcus opacus strain for renewable fuels |
| url | http://hdl.handle.net/1721.1/96820 https://orcid.org/0000-0003-1847-440X https://orcid.org/0000-0002-1015-1270 |
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