Serratia liquefaciens as a new host superior for overproduction and purification using the N-acetylneuraminate lyase gene of Escherichia coli.

Serratia liquefaciens was 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 of Escherichia coli lac operon successfully overproduced the protein independently from the inducer. Since S. liquefaciens grew at lower temperature than E. coli and its proteins were more heat sensitive than those of E. coli, simple incubation at 60 degrees C could inactivate most enzymes but the nanA protein. Subsequent column works for purification, then, became simple and rapid.