OVERPRODUCTION OF SERRATIA-MARCESCENS METALLOPROTEASE (SMP) FROM THE RECOMBINANT SERRATIA-MARCESCENS STRAINS

To overproduce Serratia marcescens metalloprotease(SMP), various recom binant plasmids encoding SMP gene were constructed and the SMP product ivities from the recombinant S. marcescens strains were examined. The recombinant S. marcescens strains indispensably required proteinaceous substrates such as casein for the extracellular production of SMP. We obtained maximum 9,100U/ml of SMP from the culture supernatant of S. marcescens ATCC27117 containing a regulatory plasmid pTSP2 encoding SM P gene fused with a strong trc99a promoter and its repressor gene lacl (q), which is about 23 times higher than that of wild type strain. SMP produced from the recombinant S. marcescens(pTSP2) was 88.3% of total extracellular proteins.