Table 3.

Kinetic parameters of germination of B. megaterium GC614 (GR null) spores complemented with GerU containing various combinations of GR D proteins^a

Strain	Relevant genotype	Kinetic parameter of germination in spores incubated with:
		Glucose			Proline
		Kmb	Vmaxc	K0.5 germb,d	Km	Vmax	K0.5 germ
GC615	pHT-gerUD gerU*e	1.7	0.05	0.24	1.7	0.05	0.24
GC631	pHT-gerUDM10stop gerU*	7.4	0.04	2.49	5.6	0.04	2.49
GC632	pHT-gerUDM10stop gerU*, with gerUD between gerUC and gerVB	1.6	0.08	0.22	1.5	0.07	0.24
GC633	pHT-gerUD gerU*, with gerKDbm between gerUC and gerVB	23.4	0.02	47	16.5	0.02	41
GC634	pHT-gerUDM10stop gerU*, with gerKDbm between gerUC and gerVB	131	0.01	276	174	0.01	305

^aSpores were germinated in 5 mM Tris-HCl, pH 7.5, for 90 min with concentrations of glucose and proline ranging from 0.1 to 1,000 mM. Germination was monitored, and kinetic parameters were calculated as described in Materials and Methods. The values for each strain are from three independent experiments conducted with the same spore preparation; similar values were obtained with at least one other spore preparation for each strain. Standard deviations from mean values are less than 10%.

^bValues given in millimolar.

^cValues represent the decrease in OD₆₀₀ units/min, where starting values are normalized to 1 OD₆₀₀ unit.

^dConcentrations of glucose and proline required to stimulate 50% spore germination [K_{0.5 germ}] were calculated after incubation for 90 min with the respective germinants. Values presented for each strain are from three independent experiments conducted with the same spore preparation; similar values were obtained with other spore preparations. Standard deviations from mean values are less than 10%.

^egerU* comprises gerUA, gerUC, and gerVB and appropriate regulatory sequences.