Adsorption of ferrous ions onto Bacillus subtilis cells

被引:45
作者
Châtellier, X
Fortin, D
机构
[1] Univ Rennes 1, CNRS, UMR 6118, F-35042 Rennes, France
[2] Univ Ottawa, Dept Earth Sci, Ottawa, ON K1N 6N5, Canada
基金
加拿大自然科学与工程研究理事会;
关键词
ferrous ions; adsorption; adsorption isotherms; desorption; FITEQL; 2.0; constant capacitance model; Bacillus subtilis; bacteria;
D O I
10.1016/j.chemgeo.2004.08.013
中图分类号
P3 [地球物理学]; P59 [地球化学];
学科分类号
0708 ; 070902 ;
摘要
Bacteria are known to have reactive surfaces that can affect the cycling of dissolved elements through sorption reactions. The properties of adsorption of various metallic ions (Cd2+, Pb2+, etc.) onto various types of Gram-positive or -negative bacterial surfaces have been measured in several previous studies, but the behavior of ferrous ions has been somewhat left out, possibly because ferrous ions are easily oxidized under standard laboratory conditions. In this paper, the adsorption of ferrous ions onto Bacillus subtilis (a Gram-positive bacterium) was measured under anoxic conditions as a function of pH for various Fe(II)/bacteria ratios. Our results first indicate that Fe(II) adsorption increased with pH and that the adsorption was reversible. An equilibration time of one hour was found sufficient to reach equilibrium between the bacterial surfaces and the solution. Acid-base titrations of the bacterial suspensions were also performed. The titration data could be fitted using a simple three-site model. Neglecting the electrostatic component, the three sites had pK values of 4.45 (pK(1)), 6.74 (pK(2)), and 9.08 (pK(3)) with corresponding concentrations of 5.6, 5.3, and 6.1 (X 10(-4) mol/dry g of bacteria), respectively. The high density of sites available for proton adsorption suggests that protons can easily diffuse within the cell walls. The adsorption data for Fe(II) was fitted with a single-site model. A Langmuir adsorption isotherm suggested that the site concentration available for the adsorption of the ferrous ions was equal to 3.5 x 10(-4) mol/g which as far less than for protons. The modeling analysis of the adsorption isotherms also indicated that the adsorption took place onto the type 2 sites (pK(2)=6.74), or type 3 sites (pK(3)=9.08) and that the adsorption constant of the Fe(II) ions onto the protonated sites was equal to -log(T) = -1.22+/-0.10. A two-site model did not improve the quality of the fit, but indicated that the type 1 sites (pK(1)=4.45) could contribute only to a limited extent to the adsorption process. (C) 2004 Elsevier B.V. All rights reserved.
引用
收藏
页码:209 / 228
页数:20
相关论文
共 50 条
[1]  
ACHOUAK W, 1994, COLLOID SURFACE B, V3, P131
[2]  
[Anonymous], 1997, AQUEOUS ENV GEOCHEMI
[3]  
ARCHIBALD AR, 1989, BACILLUS, P217
[4]   SITES OF METAL-DEPOSITION IN THE CELL-WALL OF BACILLUS-SUBTILIS [J].
BEVERIDGE, TJ ;
MURRAY, RGE .
JOURNAL OF BACTERIOLOGY, 1980, 141 (02) :876-887
[5]   Adsorption of cadmium to Bacillus subtilis bacterial cell walls:: A pH-dependent X-ray absorption fine structure spectroscopy study [J].
Boyanov, MI ;
Kelly, SD ;
Kemner, KM ;
Bunker, BA ;
Fein, JB ;
Fowle, DA .
GEOCHIMICA ET COSMOCHIMICA ACTA, 2003, 67 (18) :3299-3311
[6]   Characterization of iron-oxides formed by oxidation of ferrous ions in the presence of various bacterial species and inorganic ligands [J].
Châtellier, X ;
West, MM ;
Rose, J ;
Fortin, D ;
Leppard, GG ;
Ferris, FG .
GEOMICROBIOLOGY JOURNAL, 2004, 21 (02) :99-112
[7]   Effect of the presence of bacterial surfaces during the synthesis of Fe oxides by oxidation of ferrous ions [J].
Châtellier, X ;
Fortin, D ;
West, MM ;
Leppard, GG ;
Ferris, FG .
EUROPEAN JOURNAL OF MINERALOGY, 2001, 13 (04) :705-714
[8]  
CORNELL RM, 2003, SCHWERTMANN U
[9]   The effect of ionic strength on the adsorption of H+, Cd2+, Pb2+, and Cu2+ by Bacillus subtilis and Bacillus licheniformis:: A surface complexation model [J].
Daughney, CJ ;
Fein, JB .
JOURNAL OF COLLOID AND INTERFACE SCIENCE, 1998, 198 (01) :53-77
[10]   The effect of growth phase on proton and metal adsorption by Bacillus subtilis [J].
Daughney, CJ ;
Fowle, DA ;
Fortin, DE .
GEOCHIMICA ET COSMOCHIMICA ACTA, 2001, 65 (07) :1025-1035