This title appears in the Scientific Report :
2015
Please use the identifier:
http://dx.doi.org/10.1186/s13068-015-0209-z in citations.
Please use the identifier: http://hdl.handle.net/2128/9483 in citations.
Improved glycerol utilization by a triacylglycerol-producing Rhodococcus opacus strain for renewable fuels
Improved glycerol utilization by a triacylglycerol-producing Rhodococcus opacus strain for renewable fuels
BackgroundGlycerol 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 triacylglyc...
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Personal Name(s): | Kurosawa, Kazuhiko (Corresponding author) |
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Radek, Andreas / Plassmeier, Jens K / Sinskey, Anthony J | |
Contributing Institute: |
Biotechnologie; IBG-1 |
Published in: | Biotechnology for biofuels, 8 (2015) 1, S. 31 - |
Imprint: |
London
BioMed Central
2015
|
DOI: |
10.1186/s13068-015-0209-z |
Document Type: |
Journal Article |
Research Program: |
Biotechnology |
Link: |
OpenAccess OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://hdl.handle.net/2128/9483 in citations.
BackgroundGlycerol 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.ResultsAn 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−1 glycerol, produced 2.3 g L−1 of TAGs, corresponding to 40.4% of the cell dry weight (CDW) and 0.144 g g−1 of TAG yield per glycerol consumed. MITGM-173 was able to grow on high concentrations (greater than 150 g L−1) of glycerol. Cultivated in a medium containing an initial concentration of 20 g L−1 glycerol, 40 g L−1 glucose, and 40 g L−1 xylose, MITGM-173 was capable of simultaneously consuming the mixed substrates and yielding 13.6 g L−1 of TAGs, representing 51.2% of the CDM. In addition, when 20 g L−1 glycerol was pulse-loaded into the culture with 40 g L−1 glucose and 40 g L−1 xylose at the stationary growth phase, MITGM-173 produced 14.3 g L−1 of TAGs corresponding to 51.1% of the CDW although residual glycerol in the culture was observed. The addition of 20 g L−1 glycerol in the glucose/xylose mix resulted in a TAG yield per glycerol consumed of 0.170 g g−1 on the initial addition and 0.279 g g−1 on the pulse addition of glycerol.ConclusionWe 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. |