• Journal of Life Science
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• v.23 no.4
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• pp.560-568
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• 2013

Chungkookjang was fermented by B. subtilis MC31, a ${\gamma}$-amino butyric acid (GABA) producing microorganism. The characteristics of Chungkookjang were investigated while fermenting. Twenty four amino acids were detected in Chungkookjang, leucine was the highest of them all. Total cell populations of B. subtilis MC31 phase were between log $9.52{\pm}0.5$ ~ log $9.049{\pm}0.5$ CFU/g at stationary phase. Contents of moisture, crude ash, crude protein, crude lipid and crude fiber are $61.07{\pm}0.01%$, $1.52{\pm}0.01%$, $17.66{\pm}0.04%$, $8.96{\pm}0.03%$ and 2.61%, respectively. Contents of ammonia type nitrogen, amino type nitrogen and reducing sugar were increased during fermentation at $40^{\circ}C$ for 72 hr, however those of titratable acidity and total sugar were decreased. pH was slowly alkalized during fermentation. Viscous substance and protease contents in Chungkookjang were $4.7{\pm}0.05%$ and $0.519{\pm}7.36$ g/l, apiece. When the fibrin plate and Robbin method for fibrinolytic activity were applied, B. subtilis MC31 showed high activity. These results suggested that B. subtilis MC31 is suitable to be used as a starter to enhance the quality of Chungkookjang.