Douglas C W, Heath J, Gwynn J P
Department of Oral Pathology, University of Sheffield, UK.
FEMS Microbiol Lett. 1992 Apr 15;71(2):193-7. doi: 10.1016/0378-1097(92)90511-l.
The enzymatic activity of salivary amylase bound to the surface of several species of oral streptococci was determined by the production of acid from starch and by the degradation of maltotetraose to glucose in a coupled, spectrophotometric assay. Most strains able to bind amylase exhibited functional enzyme on their surface and produced acid from the products of amylolytic degradation. These strains were unable to utilise starch in the absence of salivary amylase. Two strains failed to produce acid from starch, despite the presence of functional salivary amylase, because they could not utilise maltose. Strains that could not bind salivary amylase failed to produce acid from starch. In no case was all the bound salivary amylase active, and two strains of Streptococcus mitis which bound amylase did not exhibit any enzyme activity on their cell surface. The ability to bind amylase may confer a survival advantage on oral bacteria which inhabit hosts that consume diets containing starch.
通过在偶联分光光度测定法中由淀粉产生酸以及将麦芽四糖降解为葡萄糖，测定了与几种口腔链球菌表面结合的唾液淀粉酶的酶活性。大多数能够结合淀粉酶的菌株在其表面表现出功能性酶，并从淀粉分解降解产物中产生酸。在没有唾液淀粉酶的情况下，这些菌株无法利用淀粉。尽管存在功能性唾液淀粉酶，但有两个菌株无法从淀粉中产生酸，因为它们不能利用麦芽糖。不能结合唾液淀粉酶的菌株无法从淀粉中产生酸。在任何情况下，并非所有结合的唾液淀粉酶都具有活性，并且两株结合淀粉酶的缓症链球菌在其细胞表面未表现出任何酶活性。结合淀粉酶的能力可能会赋予居住在食用含淀粉食物的宿主中的口腔细菌生存优势。
