Isolation, evaluation and use of two strong, carbon source-inducible promoters from Corynebacterium glutamicum
Version of Record online: 13 NOV 2009
© 2009 The Authors. Journal compilation © 2009 The Society for Applied Microbiology
Letters in Applied Microbiology
Volume 50, Issue 2, pages 173–180, February 2010
How to Cite
Okibe, N., Suzuki, N., Inui, M. and Yukawa, H. (2010), Isolation, evaluation and use of two strong, carbon source-inducible promoters from Corynebacterium glutamicum. Letters in Applied Microbiology, 50: 173–180. doi: 10.1111/j.1472-765X.2009.02776.x
- Issue online: 4 JAN 2010
- Version of Record online: 13 NOV 2009
- 2009/1214: received 7 July 2009, revised 6 October 2009 and accepted 20 October 2009
- carbon source;
- Corynebacterium glutamicum;
- E. coli–C. glutamicum shuttle vector;
- inducible promoter;
- lignocellulolytic enzyme;
Aims: To obtain strong, carbon source-inducible promoters useful for industrial applications of Corynebacterium glutamicum.
Methods and Results: DNA microarray and qRT-PCR enabled identification of the promoters of cgR_2367 (malE1) and cgR_2459 (git1) as strong, maltose- and gluconate-inducible promoters, respectively, in C. glutamicum. Promoter probe assays revealed that in the presence of the inducing sugars, PmalE1 and Pgit1, respectively, facilitated 3·4- and 4·2-fold increased β-galactosidase activities compared to the same activity induced by glucose. In addition, PmalE1 was not functional in Escherichia coli, in which Pgit1 function was repressible, which enabled the cloning of a hitherto ‘difficult-to-clone’ heterologous gene of a lignocellulolytic enzyme, whose secretion was consequently induced by the carbon sources.
Conclusions: PmalE1 and Pgit1 are strong, carbon source-inducible promoters of C. glutamicum whose characteristics in E. coli are integral to the secretion ability of C. glutamicum to secrete lignocellulolytic enzyme.
Significance and Impact of the Study: Corynebacterium glutamicum, like its counterpart industrial workhorses E. coli and Bacillus subtilis, does exhibit strong, carbon source-inducible promoters, and the functionality of two of which was demonstrated in this study. While this study may be most relevant in the ongoing efforts to establish technologies of the biorefinery, it should also be of interest to general microbiologists exploring the versatility of industrial micro-organisms. In so doing, the study should impact future advances in industrial microbiology.