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Journal of Biomedicine and Biotechnology
Volume 2009 (2009), Article ID 464986, 10 pages
http://dx.doi.org/10.1155/2009/464986
Research Article

Integrative Gene Cloning and Expression System for Streptomyces sp. US 24 and Streptomyces sp. TN 58 Bioactive Molecule Producing Strains

1Laboratory of Prokaryotic Enzymes and Metabolites, Centre of Biotechnology of Sfax, Road of Sidi Mansour Km 6, P. O. Box 1177, 3018 Sfax, Tunisia
2Laboratory of Genetic and Microbiology, UMR INRA 1128, IFR 110, Faculty of Sciences and Techniques, University Henri Poincaré, Vandoeuvre-lès-Nancy, 54 003 Nancy Cedex, France

Received 2 December 2008; Accepted 26 March 2009

Academic Editor: Isaac K. O. Cann

Copyright © 2009 Samiha Sioud et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Streptomyces sp. US 24 and Streptomyces sp. TN 58, two strains producing interesting bioactive molecules, were successfully transformed using E. coli ET12567 (pUZ8002), as a conjugal donor, carrying the integrative plasmid pSET152. For the Streptomyces sp. US 24 strain, two copies of this plasmid were tandemly integrated in the chromosome, whereas for Streptomyces sp. TN 58, the integration was in single copy at the attB site. Plasmid pSET152 was inherited every time for all analysed Streptomyces sp. US 24 and Streptomyces sp. TN 58 exconjugants under nonselective conditions. The growth, morphological differentiation, and active molecules production of all studied pSET152 integrated exconjugants were identical to those of wild type strains. Consequently, conjugal transfer using pSET152 integration system is a suitable means of genes transfer and expression for both studied strains. To validate the above gene transfer system, the glucose isomerase gene (xylA) from Streptomyces sp. SK was expressed in strain Streptomyces sp. TN 58. Obtained results indicated that heterologous glucose isomerase could be expressed and folded effectively. Glucose isomerase activity of the constructed TN 58 recombinant strain is of about eighteenfold higher than that of the Streptomyces sp. SK strain. Such results are certainly of importance due to the potential use of improved strains in biotechnological process for the production of high-fructose syrup from starch.