Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands; The State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Nijenborgh 7, 9747 AG Groningen, The Netherlands.
Carbohydr Polym. 2016 Oct 20;151:29-39. doi: 10.1016/j.carbpol.2016.05.048. Epub 2016 May 17.
Lactic acid bacteria (LAB) produce exopolysaccharides (EPS) that are important for biofilm formation in the mammalian oral cavity and gastrointestinal tract. Sucrose is a well-known substrate for homo-EPS formation by Lactobacillus reuteri glucansucrases (GS). Starch is the main fermentable carbohydrate in the human diet, and often consumed simultaneously with sucrose. Recently we have characterized L. reuteri strains that also possess 4,6-α-glucanotransferases (4,6-α-GTases) that act on starch yielding isomalto-/malto-polysaccharides. In this study we have characterized the EPS formed by L. reuteri 35-5 cells and enzymes from sucrose plus starch. The data show that both in vivo and in vitro the L. reuteri 35-5 GS and 4,6-α-GTase enzymes, incubated with sucrose plus starch, cross-react and contribute to synthesis of the final hybrid EPS products. This may have strong effects on the EPS functional properties, influence biofilm formation, and affect the relationship between dietary intake of sucrose and starch, and dental caries formation.
乳酸菌 (LAB) 产生的胞外多糖 (EPS) 对于哺乳动物口腔和胃肠道中的生物膜形成非常重要。蔗糖是乳杆菌葡聚糖蔗糖酶 (GS) 形成同型-EPS 的已知底物。淀粉是人类饮食中的主要可发酵碳水化合物，并且经常与蔗糖同时被消耗。最近，我们已经鉴定出一些具有 4,6-α-葡聚糖转移酶 (4,6-α-GTases) 的乳杆菌菌株，这些酶可以作用于淀粉生成异麦芽糖/麦芽糖多糖。在这项研究中，我们对 35-5 细胞产生的 EPS 以及来自蔗糖加淀粉的酶进行了表征。数据表明，无论是在体内还是体外，35-5 乳杆菌的 GS 和 4,6-α-GTase 酶在与蔗糖加淀粉孵育时，会发生交叉反应，并有助于最终杂交 EPS 产物的合成。这可能会对 EPS 的功能特性产生强烈影响，影响生物膜的形成，并影响蔗糖和淀粉的饮食摄入与龋齿形成之间的关系。
