A study on Alkalophilic Bacteria Producing $\beta$-Galactosidase. -Isolations and Cultural Characteristics (I)-

$\beta$-Galactosidase를 생산하는 호알카리성 세균에 관한 연구 -균주의 분리 및 배양조건 (I)-

A strain of alkalophilic Bacillus sp. YS-309 has been isolated from domestic soil. It belongs to genus Bacillus from its morphological and biochemical characteristics. The strain grows better in the alkaline media rather than in the neutral media. The optimum pH and temperature for growth were observed at 8.5 and 4$0^{\circ}C$, respectively. Glucose, lactose and maltose were appeared as good carbon source but soluble starch and fructose were utilized uneffectively for growth. Concentrations of lactose had affected both the cellular growth and the enzyme productions. The maximum growth and the highest enzyme productions were obtained at 0.5%(w/e) of lactose added in the media. B-Galactosidase from Bacillus sp. YS-309 was produced inducibly into the cell and total enzyme activities per ml were gradually decreased when the concentration of glucose increased.