engleski

Bioinformatics of Streptomyces species and food production

DNA sequences of microorganisms that are important in food production have been accumulating rapidly. This includes genome sequences of food grade organisms such as brewers' and bakers' yeast Saccharomyces cerevisiae or Lactococcus lactis used in dairy industry. Secondary products produced by Streptomyces and related genera are also important in food production in fighting infections in animals, fish and plants (e.g. tetracycline from S. aureofaciens). As well as complete genome sequences there are also many sequences of secondary metabolite biosynthesis clusters. The chromosomes of Streptomycetes are linear molecules of about 8.5 Mb in size, which makes them considerably larger than those in most other bacteria. Analysis of genomic sequences suggests that there are many clusters coding for secondary metabolites, which have not yet been detected. Bioinformatics can help in accessing the biodiversity in this group of organisms. The most important group of chemically diverse and biologically active Streptomyces compounds are the complex polyketides synthesized by Type I polyketide synthases. These multi-functional enzymes with a modular organisation share considerable DNA homology allowing prediction of polyketide structure from the DNA sequence and genetic manipulation of individual modules. The major approach that has been used up till now is targeted manipulation, e.g. disruption and replacement of certain modules involved in the biosynthetic pathways. Our work in S. rimosus showed that there is frequent recombination between the chromosome end and the linear plasmid present in the host cells. This suggested a general strategy for obtaining recombinants between two polyketide biosynthesis clusters. We are developing computer programs to model recombination between modular polyketide gene-clusters. These programs should be useful tools for predicting novel polyketide structures in silico that might then be produced by an appropriate genetics manipulation in the laboratory.

Genome sequencing; food grade microorganisms; Streptomyces species; bioinformatics

nije evidentirano