Understanding Fermentative Glycerol Metabolism and its Application for the Production of Fuels and Chemicals

Simple item page
dc.contributor.advisorGonzalez, Ramon
dc.contributor.committeeMemberZygourakis, Kyriacos
dc.contributor.committeeMemberBennett, George N.
dc.creatorClomburg, James M.
dc.date.accessioned2012-09-05T23:52:06Z
dc.date.accessioned2012-09-05T23:52:10Z
dc.date.available2014-09-05T05:10:03Z
dc.date.created2012-05
dc.date.issued2012-09-05
dc.date.submittedMay 2012
dc.date.updated2012-09-05T23:52:10Z
dc.description.abstractDue to its availability, low-price, and higher degree of reduction than lignocellulosic sugars, glycerol has become an attractive carbon source for the production of fuels and reduced chemicals. However, this high degree of reduction of carbon atoms in glycerol also results in significant challenges in regard to its utilization under fermentative conditions. Therefore, in order to unlock the full potential of microorganisms for the fermentative conversion of glycerol into fuels and chemicals, a detailed understanding of the anaerobic fermentation of glycerol is required. The work presented here highlights a comprehensive experimental investigation into fermentative glycerol metabolism in Escherichia coli, which has elucidated several key pathways and mechanisms. The activity of both the fermentative and respiratory glycerol dissimilation pathways was found to be important for maximum glycerol utilization, a consequence of the metabolic cycle and downstream effects created by the essential involvement of PEP-dependent dihydroxyacetone kinase (DHAK) in the fermentative glycerol dissimilation pathway. The decoupling of this cycle is of central importance during fermentative glycerol metabolism, and while multiple decoupling mechanisms were identified, their relative inefficiencies dictated not only their level of involvement, but also implicated the activity of other pathways/enzymes, including fumarate reductase and pyruvate kinase. The central role of the PEP-dependent DHAK, an enzyme whose transcription was found to be regulated by the cyclic adenosine monophosphate (cAMP) receptor protein (CRP)-cAMP complex, was also tied to the importance of multiple fructose 1,6-bisphosphotases (FBPases) encoded by fbp, glpX, and yggF. The activity of these FBPases, and as a result the levels of fructose 1,6-bisphosphate, a key regulatory compound, appear to also play a role in the involvement of several other enzymes during fermentative glycerol metabolism including PEP carboxykinase. Using this improved understanding of fermentative glycerol metabolism as a platform, E. coli has been engineered to produce high yields and titers of ethanol (19.8 g/L, 0.46 g/g), co-produced along with hydrogen, and 1,2-propanediol (5.6 g/L, 0.21 g/g) from glycerol, demonstrating its potential as a carbon source for the production of fuels and reduced chemicals.
dc.embargo.terms2014-09-05T05:00:00Z
dc.format.mimetypeapplication/pdf
dc.identifier.citationClomburg, James M.. "Understanding Fermentative Glycerol Metabolism and its Application for the Production of Fuels and Chemicals." (2012) Diss., Rice University. <a href="https://hdl.handle.net/1911/64609">https://hdl.handle.net/1911/64609</a>.
dc.identifier.slug123456789/ETD-2012-05-48
dc.identifier.urihttps://hdl.handle.net/1911/64609
dc.language.isoeng
dc.rightsCopyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.
dc.subjectGlycerol fermentation
dc.subjectEscherichia coli
dc.subjectMetabolic engineering
dc.subjectBiofuels
dc.subject1,2-propanediol
dc.titleUnderstanding Fermentative Glycerol Metabolism and its Application for the Production of Fuels and Chemicals
dc.typeThesis
dc.type.materialText
thesis.degree.departmentChemical and Biomolecular Engineering
thesis.degree.disciplineEngineering
thesis.degree.grantorRice University
thesis.degree.levelDoctoral
thesis.degree.nameDoctor of Philosophy
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
CLOMBURG-THESIS.pdf
Size:
3.79 MB
Format:
Adobe Portable Document Format
Download
License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
1.61 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Rice University Electronic Theses and Dissertations