Table 5. Protease specific activity and amino type nitrogen and ammonium nitrogen contents of Cheonggukjang prepared by the mixed cultures of B. subtilis MJ226 and biogenic amine-degrading lactic acid bacteria

Biogenic amines-degrading lactic acid bacteria	Protease specific activity (U/mg)	Amino type nitrogen content (mg%)	Ammonium nitrogen content (mg%)
Control	3.39±0.02	258.27±1.03	286.91±0.09
Lactobacillus acidophilus D11	4.67±0.01*	406.71±2.15*	274.74±0.04
Lactobacillus acidophilus D38	3.86±0.01*	348.90±0.97*	296.81±0.05
Lactobacillus sakei D44	4.12±0.03*	389.22±2.88*	206.35±0.06*
Lactobacillus plantarum D70	4.44±0.02*	400.27±3.05*	202.50±0.10*
Lactobacillus pentosus D74	4.89±0.05*	458.61±2.57*	155.72±0.06*

Data are means±SD from triplicate determinations.
^*Significantly differ (p<0.05) from the control group by Student’s t-test.