Institut für Mikrobiologie der Georg-August Universität Göttingen, 3400 Göttingen, Federal Republic of Germany, and Department of Food Science and Technology, School of Agriculture, Nagoya University, Chikusa, Nagoya 464 Japan.
Appl Environ Microbiol. 1987 Jul;53(7):1661-7. doi: 10.1128/aem.53.7.1661-1667.1987.
A new Clostridium strain was isolated on starch at 60 degrees C. Starch, pullulan, maltotriose, and maltose induced the synthesis of alpha-amylase and pullulanase, while glucose, ribose, fructose, and lactose did not. The formation of the amylolytic enzymes was dependent on growth and occurred predominantly in the exponential phase. The enzymes were largely cell bound during growth of the organism with 0.5% starch, but an increase of the starch concentration in the growth medium was accompanied by the excretion of alpha-amylase and pullulanase into the culture broth; but also by a decrease of total activity. alpha-Amylase, pullulanase, and alpha-glucosidase were active in a broad temperature range (40 to 85 degrees C) and displayed temperature optima for activity at 60 to 70 degrees C. During incubation with starch under aerobic conditions at 75 degrees C for 2 h, the activity of both enzymes decreased to only 90 or 80%. The apparent K(m) values of alpha-amylase, pullulanase, and alpha-glucosidase for their corresponding substrates, starch, pullulan, and maltose were 0.35 mg/ml, 0.63 mg/ml, and 25 mM, respectively.
一种新的梭状芽孢杆菌菌株在 60°C 的淀粉上被分离出来。淀粉、普鲁兰、麦芽三糖和麦芽糖诱导α-淀粉酶和普鲁兰酶的合成，而葡萄糖、核糖、果糖和乳糖则没有。淀粉酶和普鲁兰酶的形成依赖于生长，主要发生在指数生长期。在以 0.5%淀粉为生长基质的条件下，这些酶大部分与细胞结合，但当生长培养基中的淀粉浓度增加时，α-淀粉酶和普鲁兰酶被分泌到培养液中；但总活性也随之下降。α-淀粉酶、普鲁兰酶和α-葡萄糖苷酶在较宽的温度范围内（40 至 85°C）具有活性，并在 60 至 70°C 时显示出最佳的活性温度。在 75°C 下有氧条件下与淀粉孵育 2 小时后，两种酶的活性均下降至仅 90%或 80%。α-淀粉酶、普鲁兰酶和α-葡萄糖苷酶对其相应底物淀粉、普鲁兰和麦芽糖的表观 K(m)值分别为 0.35mg/ml、0.63mg/ml 和 25mM。
