TABLE 5.

Complementation of reduced phosphofructokinase activity in las mutants by expression of pfk from a plasmid

Strain	Genotypea	Growth rate (h−1)b		Sp act of phosphofructokinasec
		−Erm	+Erm	U/OD600	% of wt
MG1363	wt	0.74		5.56	100
HWA254	wt [pfk]	0.71	0.61	52.84	950
HWA217	wt las::CP25	0.46		2.18	39
HWA256	wt las::CP25 [pfk]	0.70	0.59	33.97	611
HWA232	wt las::CP29	0.56		3.34	60
HWA258	wt las::CP29 [pfk]	0.71	0.55	50.65	911

^aAll mutant strains are MG1363 derivatives. The synthetic promoters transcribing the las genes are shown. The strains in which pfk is overexpressed from pMU2916 carrying pfk are indicated. wt, wild type. 

^bSpecific growth rates are shown for cultures growing in the absence (−) or presence (+) of erythromycin. 

^cSpecific activities (U/OD₆₀₀), in micromoles per minute per cell density of phosphofructokinase are shown for culture growth in the presence of erythromycin. The activities from each strain were determined in triplicate. The specific activities of phosphofructokinase are percentages of that for MG1363.