Deichmann U, Jantzen H
Arch Microbiol. 1977 Jun 20;113(3):309-13. doi: 10.1007/BF00492040.
It could be shown that extracts of growing cultures of Acanthamoeba castellanii contained a cellulose degrading system. Reducing sugars are split off by one component of this system at an optimum of pH 4, another enzyme changes the viscosity at an optimum of pH 6, and a third component is a beta-glucosidase with an optimum at pH 3.5. At pH 4 the cellulose degradation products are cellobiose and glucose; at pH 6 higher molecular weight oligosaccharides are produced. During the development from trophozoites to cysts in a nutrient-free medium, the activities of both cellulases decline: Prior to the start of cellulose synthesis only 30%, and in cysts only 10% of the original existing activities are detectable. The biological function of the cellulase enzyme system is discussed together with a consideration of the fact that excystment takes place without digestion of the cyst wall in which the cellulose is deposited.
可以证明，卡氏棘阿米巴生长培养物的提取物含有一种纤维素降解系统。该系统的一种成分在最适pH值为4时能分解出还原糖，另一种酶在最适pH值为6时能改变粘度，第三种成分是一种最适pH值为3.5的β-葡萄糖苷酶。在pH值为4时，纤维素降解产物是纤维二糖和葡萄糖；在pH值为6时，会产生分子量更高的寡糖。在无营养培养基中从滋养体发育到包囊的过程中，两种纤维素酶的活性均下降：在开始合成纤维素之前，仅能检测到原有活性的30%，而在包囊中仅能检测到10%。同时考虑到包囊孵化时纤维素沉积其中的囊壁未被消化这一事实，对纤维素酶系统的生物学功能进行了讨论。
