| Title | 열내성이 강한 bacillus coagulans의 β-galactosidase의 특성에 대하여 | ||
| Author | 이홍금 · 홍순우 · 하영칠 · 이정치 * · 김태한 * | ||
| Address | 서울대학교 미생물학과; * 일동제약주식회사 | ||
| Bibliography | Korean Journal of Microbiology, 18(1),7-14, 1980 | ||
| DOI | |||
| Key Words | Some properties of thermostable β-galactosidase of bacillus coagulans | ||
| Abstract | A thermostrable β-galactosidase (β-galactoside galactohydorlase, EC 3.2.1.23) was inducible in Bacillus coagulans by lactose and D-glactose. The enzyme was purified 87 fold, and the optimum temeprature and pH for actiivity were determined to be 60℃ and pH 7.5, respectively. Kinetic determinations at 55℃ established a Km of 3.3mM for the chromogenic substrate onitorphenyl β-D-galactopyranoside (ONPG). Galactose and lactose were competitive inhibitors with Ki of 6.1mM and 4.9mM, respectively. The enzyme ws relatively thermostable. The crude enzyme was inactivated about 20% after 20 min of exposure at 60℃ and the purified was about 50%. Maximal enzyme activity required Mn^++, and for the thermal stabilization Fe^++ and Ca^++ were necessary. | ||
| Download PDF | Kor_180102_7-14p.pdf | ||