Overexpression and Characterization of appA Phytase Expressed by Recombinant Baculovirus-Infected Silkworm

An Escherichia coli strain with high phytase activity was screened from pig excreta. The phytase gene, appA, was amplified by PCR technique. To obtain large amounts of appA phytase, the appA gene was subcloned into the baculovirus transfer vector pVL1393 under the control of the Polyhedrin promoter. The recombinant baculovirus harboring the appA gene was obtained after co-transfection and screening. The early 5∨th instar larvae of silkworm were infected with the recombinant virus.