The invention discloses a
glucosamine synthase producing bacterium based on a
CRISPR-Cas9 technology and a construction method and application of the
glucosamine synthase producing bacterium. The
glucosamine synthase producing bacterium is obtained in the
modes that a glucosamine acetylase
gene gnal and a glucosamine synthase
gene glms are connected to a carrier pET-28a, and then a recombinant
plasmid is transferred into a double-
gene deletion
host bacterium obtained by knocking out a glucosamine
metabolism gene naggE and a glucosamine
metabolism gene mannX of an E.coli BL21(DE3)
genome through the
CRISPR-Cas9 gene editing technology. The recombinant bacterium is applied to
fermentation culture, on a
shake flask, 7.51 g / L of glucosamine can be accumulated, 3.73 g / L of
acetylglucosamine canbe accumulated, and the total output is 11.24 g / L; and on a fermentor of 5 L, 7.30 g / L of the glucosamine can be accumulated, 10.53 g / L of the
acetylglucosamine can be accumulated, and the total output is 17.83 g / L.