Adsorption of rare earth ions onto the cell walls of wild-type and lipoteichoic acid-defective strains of Bacillus subtilis
Adsorption of rare earth ions onto the cell walls of wild-type and lipoteichoic acid-defective strains of Bacillus subtilis
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DOI：
10.1007/s00253-012-4200-3
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发表时间：
2013-04-01
影响因子：
5
通讯作者：
Yamamoto, Hiroki
中科院分区：
文献类型：
--
作者：
Moriwaki, Hiroshi;Koide, Remi;Yamamoto, Hiroki
本研究的目的是调查枯草芽孢杆菌168的野生型和脂磷壁酸缺陷菌株的细胞壁吸附稀土离子的潜力。使用由两种菌株制备的冷冻干燥的细胞粉末来评价对稀土离子即La（III）、Eu（III）和Tm（III）的吸附能力。稀土离子有效地吸附到粉末的野生型菌株（WT粉末）和脂磷壁酸缺陷型菌株（匕首LTA粉末）在pH 3。WT和a dagger LTA粉末对Tm（III）的最大吸附容量分别为43和37 mg g（-1）。通过WT粉末从水溶液中去除Tm（III）、La（III）和Eu（III）（以百分比计）大于通过匕首LTA粉末。这些结果表明，稀土离子被吸附到脂磷壁酸的官能团，如磷酸根和羧基。我们观察到凝聚的匕首LTA粉末在去除稀土离子（1-20毫克L-1）从水溶液中。相比之下，WT粉末的沉降在相同条件下不发生。匕首型LTA粉末的这种独特特征可能是由脂磷壁酸和壁磷壁酸之间的分布差异引起的。看来，匕首LTA粉末是有用的去除稀土离子的吸附，因为聚集允许快速分离的吸附剂通过过滤。
The aim of this study is to investigate the potential of cell walls of wild-type and lipoteichoic acid-defective strains of Bacillus subtilis 168 to adsorb rare earth ions. Freeze-dried cell powders prepared from both strains were used for the evaluation of adsorption ability for the rare earth ions, namely, La(III), Eu(III), and Tm(III). The rare earth ions were efficiently adsorbed onto powders of both wild-type strain (WT powder) and lipoteichoic acid-defective strain (a dagger LTA powder) at pH 3. The maximum adsorption capacities for Tm(III) by WT and a dagger LTA powders were 43 and 37 mg g(-1), respectively. Removal (in percent) of Tm(III), La(III), and Eu(III) from aqueous solution by WT powder was greater than by a dagger LTA powder. These results indicate that rare earth ions are adsorbed to functional groups, such as phosphate and carboxyl groups, of lipoteichoic acid. We observed coagulated a dagger LTA powder in the removal of rare earth ions (1-20 mg L-1) from aqueous solution. In contrast, sedimentation of WT powder did not occur under the same conditions. This unique feature of a dagger LTA powder may be caused by the difference of the distribution between lipoteichoic acid and wall teichoic acid. It appears that a dagger LTA powder is useful for removal of rare earth ions by adsorption, because aggregation allows for rapid separation of the adsorbent by filtration.