The present invention discloses a preparation method and application of a
Aeromonas veronii
mutant strain, belonging to the technical field of
microbiology. The preparation method comprises the following steps: S1, extracting the whole
genome of
Aeromonas veronii; S2, constructing primers used for knocking out the cheZ / mshK / aerA genes; S3, using the extracted whole
genome of
Aeromonas veronii as a template, and using the primers to amplify the upstream and downstream homologous arms of the
target gene and perform overlap extension to obtain the deleted cheZ / mshK / aerA
gene fragment; S4, introducing the deleted cheZ / mshK / aerA
gene fragment into the suicide
plasmid pRE112 to obtain the recombinant
plasmid pRE112-ΔCMA; S5, transferring the recombinant
plasmid pRE112-ΔCMA into WM3064 competent cells, constructing a homologous recombinant
mutant strain through conjugation transfer, and then screening by
sucrose pressure to obtain the
Aeromonas veronii mutant strain ΔCMA. The present invention uses
molecular cloning technology, Overlap PCR technology and
homologous recombination technology to perform in-frame
deletion mutation on the cheZ / mshK / aerA genes of
Aeromonas veronii by using a suicide vector, and obtains a stable hereditary
Aeromonas veronii mutant strain ΔCM with three-
gene deletion.