Objective To develop a stable and effective procedure for fermentation of recombinant Yersinia pestis and purification of LcrV antigen.Methods The regularity of growth of recombinant E.coli strain pET-V / BL21(DE3) in tube and in conical flask as well as expression of LcrV antigen were investigated,based on which the medium,time point and duration for induction with IPTG and IPTG concentration were optimized and scaled up to a 30 L fermenter to develop a stable fermentation procedure.The harvested bacteria ...