Show simple item record

dc.contributor.authorLall, Davinder
dc.date.accessioned2022-01-04 20:31:27 (GMT)
dc.date.available2022-01-04 20:31:27 (GMT)
dc.date.issued2022-01-04
dc.date.submitted2021-12-21
dc.identifier.urihttp://hdl.handle.net/10012/17825
dc.description.abstractStrain engineering and bioprocessing strategies were applied for biobased production of porphobilinogen (PBG) using Escherichia coli as the cell factory. The non-native Shemin/C4 pathway was first implemented by heterologous expression of hemA from Rhodopseudomonas spheroids to supply carbon flux from the natural tricarboxylic acid (TCA) pathways for PBG biosynthesis via succinyl-CoA. Metabolic strategies were then applied for carbon flux direction from the TCA pathways to the C4 pathway. To promote PBG stability and accumulation, Clustered Regularly Interspersed Short Palindromic Repeats interference (CRISPRi) was applied to repress hemC expression and, therefore, reduce carbon flowthrough toward porphyrin biosynthesis with minimal impact to cell physiology. To further enhance PBG biosynthesis and accumulation under the hemC-repressed genetic background, we further heterologously expressed native E. coli hemB. Using these engineered E. coli strains for bioreactor cultivation based on ~30 g L-1 glycerol, we achieved high PBG titers up to 209 mg L-1, representing 1.73% of the theoretical PBG yield, with improved PBG stability and accumulation. Potential biochemical, genetic, and metabolic factors limiting PBG production were systematically identified for characterization.en
dc.language.isoenen
dc.publisherUniversity of Waterlooen
dc.subjectPorphobilinogenen
dc.subjectEscherichia Colien
dc.subjectTCA cycleen
dc.subjectSuccinyl-CoAen
dc.subjectGlycerolen
dc.subjectCRISPRien
dc.subjectShemin/C4 pathwayen
dc.titleStrain engineering and bioprocessing strategies for biobased production of porphobilinogen in Escherichia colien
dc.typeMaster Thesisen
dc.pendingfalse
uws-etd.degree.departmentChemical Engineeringen
uws-etd.degree.disciplineChemical Engineeringen
uws-etd.degree.grantorUniversity of Waterlooen
uws-etd.degreeMaster of Applied Scienceen
uws-etd.embargo.terms0en
uws.contributor.advisorChou, C.Perry
uws.contributor.advisorYoung, Murray Moo
uws.contributor.affiliation1Faculty of Engineeringen
uws.published.cityWaterlooen
uws.published.countryCanadaen
uws.published.provinceOntarioen
uws.typeOfResourceTexten
uws.peerReviewStatusUnrevieweden
uws.scholarLevelGraduateen


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record


UWSpace

University of Waterloo Library
200 University Avenue West
Waterloo, Ontario, Canada N2L 3G1
519 888 4883

All items in UWSpace are protected by copyright, with all rights reserved.

DSpace software

Service outages