Abstract:Abstract: White spot syndrome caused by white spot syndrome virus (WSSV) is the most severe epidemic virosis to shrimp culture industry in the world, resulting in tremendous economic losses. Virus envelope proteins play important roles in interacting with host cells, initiating virus infection or mediating virus intrusion. Studies about WSSV envelope proteins are numerous, but their functions haven’t been elucidated. In this study, by using a prokaryotic constitutive secretory expression plasmid as the expression vector, the recombinant Escherichia coli strain DH5α that could constitutively secrete WSSV envelope protein VP28, VP281 or VP31 were tried to be constructed. Recombinant DH5α that could constitutively secrete rVP28 and rVP281 were constructed successfully and were respectively named DhpVP28 DhpVP281. DhpVP281 grew much slowly compared with DhpVP28 and we guessed that the expression of rVP281 probably inhibited the growth of E. coli. However, recombinant bacteria constitutively expressing VP31 can not be obtained. In order to find out why recombinant bacteria that constitutively secrete rVP31 can not be constructed, recombinant bacteria BL21 (DE3) pLysS were constructed with pET-30a( ) as the expression vector and rVP31 was obtained in the form of inclusion body. After renaturation, the antibacterial activity of rVP31 was tested. The result showed that rVP31 has the antibacterial activity against Micrococcus lysodeikticus. These findings, reported for the first time, may increase the virology knowledge of WSSV.