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Dissertation/Thesis Abstract

Evaluation of the transcription of small RNA SgrS and glucose transporter mRNA ptsG in Escherichia coli B and Escherichia coli K under high glucose conditions
by Ng, Weng Ian, M.S., University of Maryland, College Park, 2009, 61; 1474311
Abstract (Summary)

Escherichia coli is commonly used as the production system for recombinant proteins. However, acetate accumulation in fermentation affects cell growth and protein yield. Recent studies have showed that the small RNA SgrS regulates the major glucose transporter mRNA ptsG in a post-transcriptional manner when the metabolic intermediate glucose-6-phosphate is accumulated intracellularly in E. coli K. Here, comparative analysis of the transcription of SgrS and ptsG is performed between E. coli B and E. coli K cultures in both shake flasks and bioreactor. Both strains expressed SgrS when grown on the non-metabolizable glucose analog α-methyl-glucoside. However, under high glucose conditions, only E. coli B showed significant expression of SgrS. This behavior is unaffected by oxygen supply and pH control. E. coli B produced less acetate on glucose than E. coli K in the bioreactor settings. This provides evidence of a possible connection between SgrS and acetate production in aerobic fermentation of E. coli.

Indexing (document details)
Advisor: Wang, Nam Sun
Commitee: Shiloach, Joseph, Sriram, Ganesh, Weigand, William A.
School: University of Maryland, College Park
Department: Chemical Engineering
School Location: United States -- Maryland
Source: MAI 48/04M, Masters Abstracts International
Subjects: Microbiology, Chemical engineering
Keywords: Escherichia coli, Glucose uptake, Post-transcriptional regulation, SgrS-ptsG mechanism, Small RNA, pts
Publication Number: 1474311
ISBN: 978-1-109-63451-8
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