Li X, Zhao C, An Q, Zhang D
Department of Bio & Food Engineering, Dalian College of Light Industry, Dalian 116034, P.R. China.
J Appl Microbiol. 2003;95(3):521-7. doi: 10.1046/j.1365-2672.2003.02006.x.
Production of isomaltulose by newly isolated Klebsiella sp. LX3.
The bacterial isolate LX3, which transforms sucrose to isomaltulose and trehalulose, has been isolated from a soil sample in Singapore. Morphological and biochemical analysis, as well as 16s rRNA sequence demonstrated that the isolate could represent a new member of genus Klebsiella. The strain has several interesting features. The immobilized cells of Klebsiella sp. LX3 convert more than 99% of sucrose to products that consist of more than 87% of isomaltulose, 11.6% of trehalulose, and <1% of glucose.
The production of isomaltulose synthase in isolate LX3 is inducible by its substrate sucrose and the sugars containing a fructofuranosyl group.
It would be useful for future biotechnological applications to understand the structural features or motifs of the isomaltulose synthases that determine the sucrose conversion efficiency and the ratio of the conversion products.
新分离的克雷伯氏菌属菌株LX3生产异麦芽糖酮糖。
从新加坡的一份土壤样本中分离出了能将蔗糖转化为异麦芽糖酮糖和海藻糖的细菌菌株LX3。形态学和生化分析以及16s rRNA序列表明该分离株可能代表克雷伯氏菌属的一个新成员。该菌株有几个有趣的特征。固定化的克雷伯氏菌属菌株LX3细胞能将超过99%的蔗糖转化为产物，这些产物中异麦芽糖酮糖占比超过87%，海藻糖占11.6%，葡萄糖占比小于1%。
分离株LX3中异麦芽糖酮糖合酶的产生可被其底物蔗糖和含有呋喃果糖基的糖类诱导。
了解决定蔗糖转化效率和转化产物比例的异麦芽糖酮糖合酶的结构特征或基序，对未来的生物技术应用将很有用。
