AEM
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
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 Santos, P. M.
Right arrow Articles by Zennaro, E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Santos, P. M.
Right arrow Articles by Zennaro, E.
Agricola
Right arrow Articles by Santos, P. M.
Right arrow Articles by Zennaro, E.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, April 2000, p. 1305-1310, Vol. 66, No. 4
0099-2240/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.

Physiological Analysis of the Expression of the Styrene Degradation Gene Cluster in Pseudomonas fluorescens ST

Pedro Miguel Santos,1 Janet Martha Blatny,2 Ilaria Di Bartolo,1 Svein Valla,3 and Elisabetta Zennaro1,*

Department of Biology, Third University of Rome, 00146 Rome, Italy,1 and Laboratory of Microbial Gene Technology, Department of Biotechnological Sciences, Agricultural University of Norway, 1432 Aas,2 and UNIGEN Center for Molecular Biology and Laboratory of Biotechnology, Norwegian University of Science and Technology, 7489 Trondheim,3 Norway

Received 23 September 1999/Accepted 11 January 2000

The effects of different carbon sources on expression of the styrene catabolism genes in Pseudomonas fluorescens ST were analyzed by using a promoter probe vector, pPR9TT, which contains transcription terminators upstream and downstream of the beta -galactosidase reporter system. Expression of the promoter of the stySR operon, which codes for the styrene two-component regulatory system, was found to be constitutive and not subject to catabolite repression. This was confirmed by the results of an analysis of the stySR transcript in P. fluorescens ST cells grown on different carbon sources. The promoter of the operon of the upper pathway, designated PstyA, was induced by styrene and repressed to different extents by organic acids or carbohydrates. In particular, cells grown on succinate or lactate in the presence of styrene started to exhibit beta -galactosidase activity during the mid-exponential growth phase, before the preferred carbon sources were depleted, indicating that there is a threshold succinate and lactate concentration which allows induction of styrene catabolic genes. In contrast, cells grown on glucose, acetate, or glutamate and styrene exhibited a diauxic growth curve, and beta -galactosidase activity was detected only after the end of the exponential growth phase. In each experiment the reliability of the reporter system constructed was verified by comparing the beta -galactosidase activity and the activity of the styrene monooxygenase encoded by the first gene of the styrene catabolic operon.

* Corresponding author. Mailing address: Department of Biology, Third University of Rome, Viale Marconi 446, 00146 Rome, Italy. Phone: 39 0655176318. Fax: 39 0655176321. E-mail: zennaro{at}bio.uniroma3.it.

Applied and Environmental Microbiology, April 2000, p. 1305-1310, Vol. 66, No. 4
0099-2240/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.


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 © 2000 by the American Society for Microbiology. All rights reserved.