TABLE 1.

Acidification, nonspecific proteolytic, and peptidase activities of 74 strains of L. helveticus

Activity	Variable	Units	Value (mean ± SD) for isolates from:
			Grana starters (n = 32)	Provolone starters (n = 42)
Acidifying	SSM3a	ΔpH	0.22 ± 0.089	0.10 ± 0.073
	SSM6	ΔpH	0.67 ± 0.280	0.32 ± 0.282
	SSM24a	ΔpH	2.86 ± 0.537	1.78 ± 0.986
	YE3	ΔpH	0.32 ± 0.107	0.39 ± 0.179
	YE6	ΔpH	1.31 ± 0.421	1.66 ± 0.539
	YE24	ΔpH	3.15 ± 0.128	3.03 ± 0.239
Nonspecific proteolytic	OPA	mg of Gly/5 ml	580 ± 150.3	371 ± 233.7
Peptidase	PHEPROa	OD580	2.05 ± 0.076	1.26 ± 0.432
	ARGa	OD580	0.28 ± 0.400	0.94 ± 0.656
	LYSa	OD580	0.57 ± 0.117	0.80 ± 0.242
	LEU	OD580	0.87 ± 0.477	1.68 ± 0.571
	PRO	OD580	0.08 ± 0.059	0.13 ± 0.051

^aSelected by stepwise LDA.