Isolation and Identification of Bacteria Producing a Soybean Milk Clotting Enzyme

두유 응고효소 생산균의 분리 및 동정

Seventeen bacterial strains producing an extracellular soybean milk clotting enzyme were Isolated from 150 soil samples, and identified as Bacillus cereus(8 strains), Bacillus pumilus(8 strains) and Bacillus licheniformis (1 strain). Among them, Bacillus pumilus strain 118 and Bacillus licheniformis strain 192 showed relatively high soybean milk clotting activity. The coagulability of enzymes from these strains decreased as the pH of soybean milk was increased from 6.0 to 7.0. The optimum temperature for soybean milk clotting activity was $65^{\circ}C$.

150개의 토양시료로부터 두유 응고효소를 생산하는 세균 17균주를 분리하였으며 이들 균주는 Bacillus cereus(8균주), Bacillus pumilus(8균주) 및 Bacillus licheniformis(1균주)로 동정하였다. 분리된 두유 응고효소 생산균주중 Bacillus pumilus 118 및 Bacillus licheniformis 192균주가 비교적 높은 두유응고효소 활성을 나타내었고 이들 두 균주의 효소활성은 pH6.0~7.0의 범위에 있어서 pH7.0에 가까울수록 저하되며 그 최적온도는 $65^{\circ}C$였다.