AEM
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Kidwell, J.
Right arrow Articles by Dennis, D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Kidwell, J.
Right arrow Articles by Dennis, D.
Agricola
Right arrow Articles by Kidwell, J.
Right arrow Articles by Dennis, D.

 Previous Article  |  Next Article 

Appl. Environ. Microbiol., 04 1995, 1391-1398, Vol 61, No. 4
Copyright © 1995, American Society for Microbiology

Regulated expression of the Alcaligenes eutrophus pha biosynthesis genes in Escherichia coli

J Kidwell, HE Valentin and D Dennis
Department of Biology, James Madison University, Harrisonburg, Virginia 22807, USA.

A novel poly-beta-hydroxybutyrate (PHB) production system in which the expression and gene dosage of the Alcaligenes eutrophus pha biosynthetic operon were effectively regulated by cultivation temperature was constructed in Escherichia coli. The pha operon was fused to the negatively regulated tac promoter and cloned into a vector in which the copy number is temperature dependent. A two-phase process was employed to produce PHB during fed-batch growth. In the growth phase, the culture was maintained at a low temperature. Under this condition, the plasmid copy number was depressed and the number of LacI proteins was sufficient to repress tacupha transcription. The production phase was initiated by temperature upshift. At the elevated temperature, the number of plasmids surpassed the number of LacI repressors, which resulted in rapid induction of tacupha transcription, synthesis of poly-beta-hydroxyalkanoate-specific proteins, and polymer synthesis. During the production phase, the PHB production rate was 1.07 g of PHB liter-1 h-1 under optimized conditions. This rate is comparable to that of bacteria which naturally produce this polymer.


This article has been cited by other articles:




Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. Microbiol. Mol. Biol. Rev. Eukaryot. Cell All ASM Journals

Copyright © 1995 by the American Society for Microbiology. All rights reserved.