Abstract：
A new exopolysaccharide (EPS) producing Gram-positive bacterium was isolated from the rhizosphere of Bouteloua dactyloides (buffalo grass) and its EPS product was structurally characterized. The isolate, designated as LB1-1A, was identified as Bacillus paralicheniformis based on 16S rRNA gene sequence and phylogenetic tree analysis. The EPS produced by LB1-1A was identified as a levan, having β(2 → 6) linked backbone with β(2 → 1) linkages at the branch points (4.66%). The isolate LB1-1A yielded large amount (~ 42 g/l) of levan having high weight average molecular weight (Mw) of 5.517 × 107 Da. The relatively low degree of branching and high molecular weight of this levan makes B. paralicheniformis LB1-1A a promising candidate for industrial applications.
摘要：
从Boutelouadactyloides（水牛草）的根际中分离出一种新的产生胞外多糖（EPS）的革兰氏阳性细菌，并对其EPS产物进行了结构表征。孤立，指定为LB1-1A，根据16SrRNA基因序列和系统发育树分析鉴定为副隐芽孢杆菌。LB1-1A生产的EPS被鉴定为果聚糖，具有β(2→6)连接的主链,在分支点具有β(2→1)连接(4.66%)。分离物LB1-1A产生大量(~42g/l)的具有5.517×107Da的高重均分子量(Mw)的果聚糖。该果聚糖的相对低的支化度和高的分子量使得副连环芽孢杆菌LB1-1A成为工业应用的有希望的候选物。
