Table 2.

Liquid fermentation conditions for nattokinase.

Strain	Carbon source	Nitrogen Source	Fermentation Time (h)	Fermentation pH	Mineral Salt	Fermentation Temperature (℃)	Enzyme Activity	References
Pseudomonas sp. TKU015	1% Shrimp shell waste	1% Shrimp shell wastes	48	7	0.1% K2HPO4 0.05% MgSO4·7H2O	30	2.3 FU/mL (fibrin as a substrate)	[16]
Bacillus subtilis Natto B-12	2% Maltose	2% Wheat	60	7	0.5% NaCl, 0.1% KH2PO4, 0.4% K2HPO4, 0.05% MgSO4·7H2O,	30	903 IU/mL (fibrin as a substrate)	[17]
Bacillus subtilis LD-8547	5% Rice powder	4% Soybean powder 0.5% NH4NO3	72	7	0.5% NH4NO3, 0.01% CaC12, 0.7% MgSO4, 0.4% K2HPO4, 0.2% KH2PO4	35	3980 U/mL (fibrin as a substrate)	[20]
Bacillus subtilis TKU007	1.5% Shrimp shell powder	-	48	7	0.1% K2HPO4, 0.05% MgSO4	30	0.35 U/mL (casein as a substrate)	[30]
Bacillus subtilis RJAS19	1% Lactose	0.5% Peptone	72	9	-	50	-	[28]
Bacillus subtilis MX-6	1% Peptone	0.3% Beef extract	72	7.2–7.4	0.04% CaCl2, 0.04% MgSO4, 0.5% NaCl	37	-	[50]
Bacillus subtilis ICTF-1	3% Maltose	0.5% Soy peptone, 1.5% Yeast extract	48	-	0.15% K2HPO4·3H2O, 0.125% MgSO4·7H2O, 0.025% CaCl2·2H2O, 1% NaCl	37	8645 U/mg (fibrin as a substrate)	[36]
Bacillus amyloliquefaciens DC-4	2% Dextrin	0.15% Yeast extract 2% fibrin, 0.5% Peptone	72	7.2	0.4% K2HPO4, 0.04% NaH2PO4, 0.3% CaCO3	37	407 U/mg (fibrin as a substrate)	[19]
Bacillus subtilis DC33	0.2% Galactose	1.4% Tryptone	72	7.2	0.1% KH2PO4, 0.2% Na2HPO4, 0.02% MgSO4, 0.3% CaCO3, 0.001% FeCl3, 0.001% LiSO4	37	447.4 U/mg (fibrin as a substrate)	[21]