This application discloses a recombinant
bacterial strain that highly expresses nonspecific peroxygenase, its construction method, and its applications, relating to the field of microbial
engineering technology. The strain of this invention uses *
Escherichia coli* BL21(DE3) as the host. First, the key
gene *hemA* for
heme synthesis is integrated into the
genome using the
CRISPR-transposon
system. Then, a
chassis engineered strain A2 with 2 copies of optimal integration is screened and co-transformed with the rDcaUPO-A161C expression
plasmid and the molecular chaperone
plasmid pG-KJE8. The
intracellular heme level of this strain is increased by 2.84 times compared to the original strain, and the total
enzyme activity of rDcaUPO-A161C is cumulatively increased by 8.9 times and the
specific enzyme activity is increased by 6.21 times compared to the
wild type. This fundamentally solves the problems of insufficient cofactors, low folding efficiency, and poor activity in
heterologous expression of nonspecific peroxygenases, and can be used for the efficient production of nonspecific peroxygenases.