Serratia liquefaciensas a New Host Superior for Overproduction and Purification Using theN-Acetylneuraminate Lyase Gene ofEscherichia coli

Serratia liquefacienswas screened as a host strain for effective gene expression and easy purification of the target protein. A model gene,N-acetylneuraminate lyase gene (nanA), fused with the promoter region ofEscherichia coli lacoperon successfully overproduced the protein independently from the inducer. SinceS. liquefaciensgrew at lower temperature thanE. coliand its proteins were more heat sensitive than those ofE. coli,simple incubation at 60°C could inactivate most enzymes but thenanA protein. Subsequent column works for purification, then, became simple and rapid.