Institut für Mikrobiologie der Georg-August Universität Göttingen, 3400 Göttingen, Federal Republic of Germany.
Appl Environ Microbiol. 1987 Jul;53(7):1668-73. doi: 10.1128/aem.53.7.1668-1673.1987.
The production of alpha-amylase, pullulanase, and alpha-glucosidase and the formation of fermentation products by the newly isolated thermophilic Clostridium sp. strain EM1 were investigated in continuous culture with a defined medium and an incubation temperature of 60 degrees C. Enzyme production and excretion were greatly influenced by the dilution rate and the pH of the medium. The optimal values for the formation of starch-hydrolyzing enzymes were a pH of 5.9 and a dilution rate of 0.075 to 0.10 per h. Increase of the dilution rate from 0.1 to 0.3 per h caused a drastic drop in enzyme production. The ethanol concentration and optical density of the culture, however, remained almost constant. Growth limitation in the chemostat with 1% (wt/vol) starch was found optimal for enzyme production. Under these conditions 2,800 U of pullulanase per liter and 1,450 U of alpha-amylase per liter were produced; the amounts excreted were 70 and 55%, respectively.
新分离的嗜热梭菌 EM1 菌株在以限定培养基和 60°C 孵育温度进行连续培养时，其α-淀粉酶、普鲁兰酶和α-葡萄糖苷酶的生产以及发酵产物的形成情况得到了研究。酶的产生和分泌受到稀释率和培养基 pH 值的极大影响。淀粉水解酶形成的最佳值为 pH 值 5.9 和稀释率 0.075 至 0.10/h。稀释率从 0.1 增加到 0.3/h 会导致酶产量急剧下降。然而，乙醇浓度和培养物的光密度几乎保持不变。在 1%（wt/vol）淀粉的恒化器中发现生长限制最有利于酶的生产。在此条件下，每升可产生 2800U 的普鲁兰酶和 1450U 的α-淀粉酶；分泌量分别为 70%和 55%。
