Genome Shuffling Of Daunomycin- Producing Streptomyces Coeruleorubidus SIPI 1482 M1

For millennia, selective breeding, on the basis of biparental mating, has led to successful strain improvement to meet societal needs. At a molecular level, DNA shuffling mimics, yet accelerates, evolutionary processes and allows the breeding and improvement of individual genes and subgenomic DNA fragments. Genome shuffling is a process that combines the advantage of multi-parental crossing allowed by DNA shuffling with the recombination of entire genomes normally associated with conventional breeding.This research is aimed to improve DNR productivity by genome shuffling. The results are as follows.Different pretreatments and determination methods of fermentation broth were tested. After optimization, we established a rapid and precise determination method which is satisfied in large-scale fermentation screening.The conditions for protoplast preparation ,fusion and regeneration of SIPI 1482 Ml were optimized. We used protoplast UV radiation to obtain a population of slightly improved phenotype called pop-UV. Then we shuffled pop-UV by genome shuffing. Also,the control experiement is done by protoplast preparation and regeneration without PEG induced fusion.The population of F4,which is obtained after four rounds of shuffling, remarkably improved self-resistance. Selected shuffled strains"s yields are 60% more than the original strain by shake flask screening and HPLC determination. While the controlled P4 had only slightly improvement than the strarting strain. Thus, it is indicated that the key to successful application of genome shuffling is PEG-induced recursive protoplast fusion.We show that recursive genomic recombination within a population of bacteria can efficiently generate combinatorial libraries of new strains. When applied to a population of phenotypically selected bacteria, many of these new strains show marked improvements in the selected phenotype. We demonstrate the use of this approach through the rapid improvement of DNR production from Streptomyces coeruleorubidus.This approach has the potential to facilitate cell and metabolic engineering and is an effective approach for the rapid improvement of industrially important microbial phenotypes. Thus provide a non-recombinant alternative to the rapid production of improved organisms.