Team:BNU-China
Screening for Advantageous Mutants
— a Self-enrichment System
Bioengineering uses stable, highly productive mutants, target strains, which contain foreign genes. However, screening these mutants costs vast time and workforce, and it is difficult to avoid using antibiotics. We applies synthetic biology methods, constructing a novel pathway to screen mutants by giving target strains growth advantages. Here, utilizing AND gate, the gene of interest expresses to a certain level, making the downstream pchAB gene express and catalyze the generation of salicylic acid（SA）. SA can activate the expression of glucose dehydrogenase, which gives the target strains an additional growth advantage. Besides, we integrate the most important control module of the system into the genome using Chemically Inducible Chromosomal Evolution(CIChE). In summary, the target strain will finally obtain the greatest growth advantage in bacterial suspensions and achieve screening internally. This new screening method is simple to operate and provides a new idea for antibiotic-free screening.
MUTATION-from natural to synthetic
The new methods of self-screening made it possible to select more beneficial mutations