100_genome_project

In contrast to modern rational metabolic engineering, classical strain development strongly relies on random mutagenesis and screening for the desired production phenotype. Nowadays, with the availability of biosensor-based FACS-screening strategies, these random approaches are coming back into fashion. In this study, we employ this technology in combination with comparative genome analyses to identify novel mutations contributing to product formation in the genome of a Corynebacterium glutamicum L histidine producer. For the identification of 100 improved strain variants, we performed > 600 chemical mutagenesis, > 200 biosensor-based FACS-screenings, isolated > 50,000 variants with increased fluorescence, and characterized > 4,500 variants with regard to biomass formation and L-histidine production. Based on comparative genome analyses of these 100 variants accumulating 10-80% more L histidine, we discovered several beneficial mutations.