Biosorption of metals (Cu2+, Zn2+) and anions (F-, H2PO4-) by viable and autoclaved cells of the Gram-negative bacterium Shewanella putrefaciens
Biosorption of metals (Cu2+, Zn2+) and anions (F-, H2PO4-) by viable and autoclaved cells of the Gram-negative bacterium Shewanella putrefaciens
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DOI：
10.1016/j.colsurfb.2008.03.006
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发表时间：
2008-08-01
影响因子：
5.8
通讯作者：
Van Cappellen, Philippe
中科院分区：
文献类型：
--
作者：
Chubar, Natalia;Behrends, Thilo;Van Cappellen, Philippe
微生物生物量代表了水处理应用中具有潜在成本效益的吸附剂。高的阳离子和阴离子的吸附能力在这里证明了活的和高压灭菌的革兰氏阴性细菌腐坏谢瓦氏菌的细胞悬浮液。FTIR吸收光谱和ph依赖的ζ电位对活菌和死菌细胞是相似的。然而，电位滴定法显示活细胞的OH缓冲能力提高了两到三倍。活性细胞对Cu2+的吸附能力也大约是高压灭菌细胞的两倍。氟化物和磷酸盐的吸附不依赖于ph值，尽管最初需要添加酸或碱来激活阴离子结合位点。存活细胞和死亡细胞对氟化物的吸收是相当的。对于活细胞，Zn2+和Cu2+的等温线表明至少存在两个不同的细胞壁结合位点群体。在竞争性吸附实验中，Cu2+在150 mg L-1以上的水溶液浓度下完全抑制Zn2+与细胞的结合。活细胞释放溶解的有机化合物取决于细胞所暴露的金属阳离子或氟化物的浓度。特别是Cu2+的存在几乎完全抑制了蛋白样物质的释放，这可能反映了Cu2+的毒性。(C) 2008 Elsevier B.V.版权所有
Microbial biomass represents a potentially cost-effective sorbent for water treatment applications. High sorption capacities for both cations and anions are demonstrated here for viable and autoclaved cell suspensions of the Gram-negative bacterium Shewanella putrefaciens. FTIR absorption spectra and pH-dependent zeta-potentials are similar for the viable and killed bacterial cells. Potentiometric titrations, however, reveal a two to three times higher OH- buffering capacity for the living cells. The Cu2+ sorption capacity of the viable cells is also about twice that of the autoclaved cells. Sorption of fluoride and phosphate is not pH-dependent, although an initial addition of acid or base was needed to activate the anion binding sites. Uptake of fluoride is comparable for viable and killed cells. For the viable cells, the isotherms of Zn2+ and Cu2+ indicate the presence of at least two distinct populations of cell wall binding sites. In competitive sorption experiments, Cu2+ Completely inhibits the binding of Zn2+ to the cells at aqueous concentrations above 150 mg L-1. The release of dissolved organic compounds by the viable cells depends on the concentrations of metal cations or fluoride to which the cells are exposed. In particular, the presence of Cu2+ nearly completely suppresses the release of protein-like substances, possibly reflecting Cu2+ toxicity. (C) 2008 Elsevier B.V. All rights reserved.