Biotechnological Application of Multidrug Transporters from Bacillus cereus for the production of Secondary Metabolites in Streptomyces

Bacillus cereus and Streptomyces are soil-dwelling gram-positive bacteria. The Bacillus cereus group of bacteria has probably the highest number of sequenced train. Today 85 strains have been sequenced, and we have analysed the multidrug transporters (MDR ) in these strains. Thirty MDR genes are conserved in all strains. We are making markerless knockout of one third of these conserved MDR genes and in addition we are cloning them and expressing them in E. coli. One of the most studied conserved multidrug transporter is BC4707 and the expressed protein has been shown to function as an efflux transporter of a large variety of compunds in E. coli and has been selected for this project. The group of professor Bercthold at the University of Freiburg has exten sive experience in the analysis of Streptomyces species and strains, for the production of secondary metabolites, like the antibiotic kanamycin. In addition his lab also has experience in heterologous gene expression in Streptomyces. In this new project we want to express transporters from Bacillus cereus ATCC 14579 (type strain) in Streptomyces and thus analyse whether the resulting strains will be more efficient in producing and exporting secondary metabolites that might be of interest as novel antibio tics. Both sequenced and unsequenced strains of Streptomyces will be used. The work will start with the well investigated and sequenced strains Streptomyces coelicolor and Streptomyces avermitilis. An application has been submitted to DAAD from professor Andreas Bechthold at the University of Freiburg and PhD student Jasmin Kroeger. The project description submitted is the same in both applications.