Recycling acetate for improving flavanones production from Escherichia coli
by Saw, Phan Nee, M.S., STATE UNIVERSITY OF NEW YORK AT BUFFALO, 2007, 114 pages; 1446261

Abstract:

Acetate is a toxic by-product of glucose metabolism in Escherichia coli. In the present work, endogenous metabolic networks of E. coli were re-designed to improve the autonomous recycling of acetate into acetyl-CoA. In conjunction with the elevation of acetyl-CoA carboxylase level, the metabolic engineering strategy was implemented to improve the recombinant productions of high-value plant-derived flavonoids. Together with overexpression of acetyl-CoA carboxylase (ACC) subunits from Photorhabdus luminescens (PlACC), amplification of the high affinity acetate assimilation enzyme acetyl-CoA synthetase (ACS) resulted in high level production of three flavonoids tested. Overall, the metabolic engineering of central metabolic pathways described in the present work increased the production of naringenin, eriodictyol, and pinocembrin up to 183%, 373%, and 1379% respectively over control strains in 40 h, which corresponded to 119 mg/L, 52 mg/L, and 429 mg/L. The elevation of the low affinity acetate pathway comprising of phosphotransacetylase (PTA) and acetate kinase (ACK) resulted in a similar improvement of flavonoid production. It is evident that metabolic engineering methods to recycle waste products can be used to improve the production of high-value heterologous metabolites.

 
AdvisersMattheos A.G. Koffas; Manolis Tzanakakis
SchoolSTATE UNIVERSITY OF NEW YORK AT BUFFALO
SourceMAI/ 46-02, p. , Dec 2007
Source TypeThesis
SubjectsGenetics; Pharmaceutical Chemistry; Chemical engineering
Publication Number1446261
Adobe PDF Access the complete dissertation:
 

» Find an electronic copy at your library.
  Use the link below to access a full citation record of this graduate work:
  http://gateway.proquest.com/openurl%3furl_ver=Z39.88-2004%26res_dat=xri:pqdiss%26rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation%26rft_dat=xri:pqdiss:1446261
  If your library subscribes to the ProQuest Dissertations & Theses (PQDT) database, you may be entitled to a free electronic version of this graduate work. If not, you will have the option to purchase one, and access a 24 page preview for free (if available).

About ProQuest Dissertations & Theses
With over 2.3 million records, the ProQuest Dissertations & Theses (PQDT) database is the most comprehensive collection of dissertations and theses in the world. It is the database of record for graduate research.

The database includes citations of graduate works ranging from the first U.S. dissertation, accepted in 1861, to those accepted as recently as last semester. Of the 2.3 million graduate works included in the database, ProQuest offers more than 1.9 million in full text formats. Of those, over 860,000 are available in PDF format. More than 60,000 dissertations and theses are added to the database each year.

If you have questions, please feel free to visit the ProQuest Web site - http://www.proquest.com - or call ProQuest Hotline Customer Support at 1-800-521-3042.