The invention provides a
genetically engineered bacterium and a construction method of the
genetically engineered bacterium, and the
genetically engineered bacterium is characterized in that a
green fluorescent protein sfGFP is used for mediating
protein glutaminase, PG (
protein glutaminase), PGF (
protein glutaminase), PGF, PGF, PGF, PGF, PGF, PGF, PGF, PGF, PGF, PGF, PGF, PGF, PGF, PGF, PGF, PGF and PGF; eC 3.5. 1.44) is efficiently secreted and expressed in
engineering bacteria, and belongs to the technical field of
biological engineering. The method comprises the following steps: an obtained sfGFP
gene is derived from an NCBI
database (
GenBank numbering: CP035486.1), an obtained PG
zymogen gene PP (Propeptide-
Protein glutaminase) is derived from a
Chryseobacterium prion prgA
gene (
GenBank numbering: AB046594.1) in the NCBI
database, a recombinant
plasmid pHT01 / sfGFP-PP is introduced into
bacillus subtilis WB800N to obtain an
engineering bacterium,
extracellular secretion expression of PP is realized, the sfGFP-PP is activated by
trypsin to obtain PG, and the PG is subjected to
enzyme activation to obtain the recombinant
bacillus subtilis. The expression quantity and the
secretion efficiency of the PG in the
bacillus subtilis are greatly improved. The recombinant PG produced by the method can generate 23.5 U / mL enzymatic activity under activation of
trypsin, can be used for improving protein functional characteristics, and has relatively high industrial production and application values.