The invention relates to a continuous evolution
system based on a T7
RNA polymerase mutant and application of the continuous evolution
system, and belongs to the technical field of evolution
engineering. The method comprises the following steps: on the basis of a T7
RNA polymerase mutant with a single-stranded
DNA synthesis capability, constructing a continuous evolution
system containing a single-stranded
DNA synthesis template and the T7
RNA polymerase mutant, introducing the continuous evolution system into a host, and recombining the T7
RNA polymerase mutant with a
target gene by synthesizing single-stranded
DNA, so that the host constructs a mutant
library in a continuous passage process, screening pressure is applied to the host, and the host realizes continuous evolution. By applying the system, evolution of
tetracycline efflux pump
protein is completed within 7 days, the
tryptophan defect of
saccharomyces cerevisiae is repaired within 24 hours, the
tetracycline efflux pump
protein mutant obtained through screening can tolerate
tetracycline and
tigecycline, the tolerance to the
tigecycline is increased by 8 times, the tolerance to the tetracycline is increased by 2 times, and the tetracycline
efflux pump
protein mutant has the advantages that the tetracycline efflux pump protein mutant can tolerate the tetracycline and the
tigecycline. The important significance is realized on improving the
cell factory performance.