pfl genes from mannheimia succiniciproducens 55e mannheimia succiniciproducens 55e was plated on lb glucose medium containing 10 g l of glucose and cultured at 37 u00b0 c for 36 hours the colony formed was inoculated in 10 ml of lb glucose liquid medium and cultured for 12 hours the culture broth which had been sufficiently grown was inoculated by 1 in 100 ml of lb glucose liquid medium and cultured in a shaking incubator at 200 rpm and 37 u00b0 c when the culture broth reached an od of about 0 2 0 3 after 4 u02dc 5hours it was centrifuged at 4 u00b0 c and 4000 rpm for 10 minutes to collect cells then the cells were resuspended in 200 ml of 10 glycerol solution at 4 u00b0 c the suspension was centrifuged at 4 u00b0 c and 4000 rpm for 10 minutes and the cells were collected and resuspended in 200 ml of 10 glycerol solution at 4 u00b0 c and then centrifuged at 4 u00b0 c and 4000 rpm for 10 minutes to collect the cells the cells were suspended in glycerol at a volume ratio of 1 1 to obtain cell concentrate the cell concentrate thus obtained was mixed with the genetic exchange vectors pmlko sacb.