Novel antimicrobial activities of a peptide derived from a Japanese soybean fermented food, Natto, against Streptococcus pneumoniae and Bacillus subtilis group strains

AMB Express

Table 4 The effect of medium supplemented with horse hemolysate, hose serum, and hemin on the MIC of the Natto peptide with S. pneumoniae R6 strain

Supplement	Concentration^b	MIC (μg/mL)
None	–	>128
Horse hemolysate^a	5%	8
	1%	4
	0.32%	4
	0.10%	8
	0.032%	32
	0.010%	64
	0.0032%	128
	0.0010%	>128
Supernatant of heat-treated horse hemolysate	20%	4
	5%	32
Horse serum	5%	>128
Hemin^a	6.9 μg/mL	8
	3.4 μg/mL	32
	1.7 μg/mL	64
	0.86 μg/mL	128
	0.43 μg/mL	>128

^aHose hemolysate [5%(v/v)] and hemin (6.9 μg/mL) did not any antimicrobial effects against S. pneumoniae
^bThe percent concentrations are (v/v)