Flocculation behavior and mechanism of an exopolysaccharide from the deep-sea psychrophilic bacterium Pseudoalteromonas sp SM9913
Flocculation behavior and mechanism of an exopolysaccharide from the deep-sea psychrophilic bacterium Pseudoalteromonas sp SM9913
复制标题
深海嗜冷细菌假交替单胞菌 SM9913 胞外多糖的絮凝行为及机制
DOI：
10.1016/j.biortech.2008.01.050
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发表时间：
2008-10-01
影响因子：
11.4
通讯作者：
Zhu, X. B.
中科院分区：
文献类型：
--
作者：
Li, W. W.;Zhou, W. Z.;Zhu, X. B.
研究了从深海沉积物中分离的一株嗜冷菌Pseudoalteromonassp.SM9913（EPS SM 9913）分泌的胞外多糖的絮凝行为及其机理。EPS SM 9913在1g/L高岭土悬浮液中的最高酶活为49.3，最适pH范围为5 ~ 8，最适CaCl 2浓度为4.55mmol/L。结果表明，胞外多糖SM 9913的酶活性受Ca ~（2+）和Fe ~（2+）的刺激。本研究发现，EPS SM 9913在5-100 ppm盐度或5-15 ℃温度下显示出比Al-2（SO 4）（3）更好的絮凝性能。此外，这种EPS是有效的絮凝其他几种悬浮固体。所测得的zeta电位，絮凝过程中形成的絮凝体的大小和絮凝体的表面轮廓显示通过扫描电子显微镜表明，桥接是研究的EPS的主要絮凝机制。EPS SM 9913的脱乙酰基导致其絮凝活性显著降低，表明EPS SM 9913中大量的乙酰基对其絮凝性能起重要作用。(C)2008爱思唯尔有限公司保留所有权利。
Flocculation behavior and mechanism of the exopolysaccharide secreted by Pseudoalteromonas sp. SM9913 (EPS SM9913), a psychrophilic bacterium isolated from 1855 in deep-sea sediment, has been studied in this paper. EPS SM9913 showed a peak flocculating activity of 49.3 in 1 g/L kaolin suspension with 4.55 mmol/L CaCl2 and the optimum pH range of 5-8. It appears that the flocculating activity of EPS SM9913 was stimulated by Ca2+ and Fe2+. This study found that EPS SM9913 showed a better flocculation performance than Al-2(SO4)(3) at salinity of 5-100 parts per thousand or temperatures of 5-15 degrees C. In addition, this EPS was effective to flocculate several other suspended solids. The measured zeta-potentials, the size of floes formed during the flocculation process and the surface profile of floes revealed by scan electron micrograph suggest that bridging is the main flocculation mechanism of the studied EPS. Deacetylation of EPS SM9913 resulted in a significant decrease in its flocculating activity indicating that the large number of acetyl groups in EPS SM9913 played an important role in its flocculation performance. (C) 2008 Elsevier Ltd. All rights reserved.