TABLE 5.

K_m and V_max values for conversion of sucrose into isomaltulose and trehalulose by purified SIs from P. dispersa UQ68J and K. planticola UQ14S^a

Parameter	UQ685						UQ145
	Sucrose	Sucrose + 69 mM glucose	Sucrose + 139 mM glucose	Sucrose + 277 mM glucose	Sucrose + 277 mM fructose	Sucrose + 277 mM glucose + 277 mM fructose	Sucrose	Sucrose + 69 mM glucose	Sucrose + 139 mM glucose	Sucrose + 277 mM glucose	Sucrose + 277 mM fructose	Sucrose + 277 mM glucose + 277 mM fructose
Isomaltulose production
Km (mM)	40	56	76	164	72	3,017	76	102	138	329	170	709
Vmax (U mg−1)	638	623	627	635	624	636	423	423	416	431	430	403
Trehalulose production
Km (mM)	71	140	244	1,009	168	670	147	241	360	687	368	3,012
Vmax (U mg−1)	36	36	35	35	39	35	116	115	115	111	117	118

^aThe data are means for three enzyme reaction replicates. The kinetic constants were obtained from Lineweaver-Burk plots with sucrose concentrations of 2.92, 5.84, 14.6, 58.4, and 146 mM.