Department of Biochemistry and Microbiology, Plovdiv University, Plovdiv, Bulgaria.
Appl Biochem Biotechnol. 2012 Oct;168(3):718-30. doi: 10.1007/s12010-012-9812-7. Epub 2012 Aug 30.
Glycosyltransferase activity of 13 Leuconostoc mesenteroides strains isolated from Bulgarian fermented vegetables was investigated. All the strains displayed a mucoid phenotype on sucrose-containing agar media. Strains were characterized according to carbohydrate fermentation, species-specific multiple PCR using several primers, repetitive element-PCR fingerprinting using (GTG)(5) primers and glycosyltransferase activity. Level of activity and cellular localization (soluble or cell-associated) were variable among strains. Precipitation of exopolysaccharides produced from sucrose by the soluble fractions from these strains allowed recovery of only glucans and further characterization by (1)H and (13)C NMR analysis and enzymatic digestion with dextranase revealed dextran production. However, levans could be detected in presence of raffinose as fructosyl donor. Both fructosyltransferase and glucosyltransferase encoding genes were detected by PCR and both active enzymes were detected after functional characterization by SDS-PAGE electrophoresis and in situ polymer production after incubation with sucrose. This work therefore showed that concomitant production of glucosyltransferase and fructosyltransferase is widespread in L. mesenteroides strains.
从保加利亚发酵蔬菜中分离出的 13 株肠膜明串珠菌的糖基转移酶活性进行了研究。所有菌株在含有蔗糖的琼脂培养基上均表现出粘液表型。根据碳水化合物发酵、使用多种引物的种特异性多重 PCR、使用 (GTG)(5) 引物的重复元件-PCR 指纹图谱和糖基转移酶活性对菌株进行了特征描述。菌株间的活性水平和细胞定位（可溶性或细胞相关）存在差异。这些菌株的可溶性部分从蔗糖中沉淀产生的胞外多糖，仅能回收葡聚糖，并通过（1）H 和（13）C NMR 分析和用葡聚糖酶进行酶解进一步进行表征，揭示了葡聚糖的产生。然而，在存在棉子糖作为果糖供体的情况下，可以检测到莱聚糖。通过 PCR 检测到果糖基转移酶和葡糖基转移酶编码基因，通过 SDS-PAGE 电泳和在与蔗糖孵育后原位聚合产物的功能特征描述检测到两种活性酶。因此，这项工作表明，肠膜明串珠菌菌株中普遍存在同时产生葡糖基转移酶和果糖基转移酶的现象。
