枯草芽孢杆菌细胞及其胞外多糖对活性蓝 4 的固定化和游离态的螯合作用。
Sequestration of Reactive Blue 4 by free and immobilized Bacillus subtilis cells and its extracellular polysaccharides.
机构信息
Department of Food Science and Technology, College of Agriculture and Life Science, Chonbuk National University, Jeonju, Republic of Korea.
出版信息
Colloids Surf B Biointerfaces. 2010 Mar 1;76(1):179-85. doi: 10.1016/j.colsurfb.2009.10.031. Epub 2009 Oct 30.
Bacillus subtilis a gram positive bacteria and its extracellular polysaccharide were used in free form as well as immobilized form as biosorbent for sequestration of an anionic dye, Reactive Blue 4 (RB) in aqueous phase. The dye uptake enhanced with decrease in pH. Extracellular polymeric substances (EPS) and free cells were found to be better adsorbents when compared to alginate immobilized cells (IC) and EPS (IEPS). The presence of functional groups in free cells and EPS was confirmed by FT-IR analysis. Immobilization resulted in poor adsorption performance due to increase in mass transfer resistance by the polymeric matrix. High Q(max) and b values were noted in the case of free cells and free EPS in contrast to IC and IEPS. From the kinetic experiments, the adsorption system was found to be a pseudo-first-order reaction at low dye concentration. Desorption of RB was found to be 100% in 1N NaOH. However, the alginate beads were found to be unstable under high alkaline conditions of NaOH.
枯草芽孢杆菌是一种革兰氏阳性细菌，其胞外多糖既可以自由形式，也可以固定化形式作为生物吸附剂，用于从水相中吸附阴离子染料活性蓝 4（RB）。染料的摄取量随 pH 值的降低而增加。与海藻酸钠固定化细胞（IC）和胞外多聚物（IEPS）相比，胞外多聚物（EPS）和游离细胞被发现是更好的吸附剂。通过傅里叶变换红外（FT-IR）分析证实了游离细胞和 EPS 中存在官能团。由于聚合基质增加了传质阻力，固定化导致吸附性能变差。与 IC 和 IEPS 相比，游离细胞和游离 EPS 的 Q(max)和 b 值较高。从动力学实验来看，在低染料浓度下，吸附体系是准一级反应。在 1N NaOH 中，RB 的解吸率达到 100%。然而，在高碱性 NaOH 条件下，海藻酸钠珠粒被发现不稳定。
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