(EN) The present invention provides a production method for bacterial cells that, in a multi-stage liquid cultivation process for bacteria, includes a step in which, in the stage prior to the final stage, the bacteria are cultivated using a liquid medium containing an antibiotic substance, and in the final stage, the bacteria are cultivated upon reducing the concentration of the antibiotic substance to below that of the prior stage. It is thereby possible to produce the bacterial cells with excellent yield while suppressing the appearance of mutant individuals forming aberrant colonies in the bacteria obtained after cultivation.
