The effect of growth phase on proton and metal adsorption by Bacillus subtilis

Daughney, Christopher J.; Fowle, David A.; Fortin, Danielle

doi:10.1016/s0016-7037(00)00587-1

Cited by 135 publications

(114 citation statements)

References 40 publications

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“…Some of the model parameters are similar to previously published results (Table 3), although the diversity of biosorbants and modeling approaches described in the literature somewhat limit the comparisons that can be made. The deprotonation constant pK values determined for site 2 and site 3 for both Geobacillus strains are in good agreement with recent results reported for the thermophilic species TOR-39 (42) and Anoxybacillus flavithermus (11), the mesophilic bacterium Bacillus subtilis (16), and five natural bacterial consortia (5). The pK values of site 1 for G. stearothermophilus and G. thermocatenulatus are considerably lower than those reported for the other bacteria and may indicate that a different type of functional group is involved in complexation reactions for species of the genus Geobacillus.…”

Section: Discussionsupporting

confidence: 91%

“…The thermodynamic stability constant K for cadmium ion binding are not as high for the Geobacillus strains as for the other bacteria described in the literature (5,11,16,42,43). We acknowledge that the differences may be due to different modeling approaches employed.…”

Section: Discussionmentioning

confidence: 89%

“…Several recent investigations have used surface complexation models (SCMs) to describe the extent of metal adsorption by bacteria as important physical, chemical, and biological parameters are independently varied (5,8,14,16,19,23,43). These SCMs are based upon a set of molecular-scale thermodynamic reactions, each describing adsorption of a particular dissolved chemical species to a particular type of cell wall functional group using a single stability constant, K. Some previous investigations indicate that different bacterial species display similar types of reactive surface functional groups (e.g., carboxyl, phosphoryl, hydroxyl, or amine) and exhibit broadly similar reactivities toward certain metals (5,43).…”

mentioning

confidence: 99%

“…However, cadmium compounds are important environmental pollutants affecting most eukaryotic and bacterial cells. Cadmium was also selected in the present investigation because SCMs describing the adsorption of cadmium by various mesophilic bacteria are available for comparison (5,8,14,16,19,43). In this study, we initially tested 26 thermophilic bacteria of the genera Aneurinibacillus, Anoxybacillus, Bacillus, Brevibacillus, and Geobacillus in cadmium ion toxicity experiments.…”

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confidence: 99%

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Cadmium Ion Biosorption by the Thermophilic Bacteria Geobacillus stearothermophilus and G. thermocatenulatus

Hetzer

Daughney

Morgan

2006

Appl Environ Microbiol

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This study reports surface complexation models (SCMs) for quantifying metal ion adsorption by thermophilic microorganisms. In initial cadmium ion toxicity tests, members of the genus Geobacillus displayed the highest tolerance to CdCl 2 (as high as 400 to 3,200 M). The thermophilic, gram-positive bacteria Geobacillus stearothermophilus and G. thermocatenulatus were selected for further electrophoretic mobility, potentiometric titration, and Cd 2؉ adsorption experiments to characterize Cd 2؉ complexation by functional groups within and on the cell wall. Distinct one-site SCMs described the extent of cadmium ion adsorption by both studied Geobacillus sp. strains over a range of pH values and metal/bacteria concentration ratios. The results indicate that a functional group with a deprotonation constant pK value of approximately 3.8 accounts for 66% and 80% of all titratable sites for G. thermocatenulatus and G. stearothermophilus, respectively, and is dominant in Cd 2؉ adsorption reactions. The results suggest a different type of functional group may be involved in cadmium biosorption for both thermophilic strains investigated here, compared to previous reports for mesophilic bacteria.Various metal compounds can be either essential or toxic for living organisms, depending on the form and concentration. In important physiological catalytic reactions, many enzymes require metal ions as central atoms. In order to generate energy, several microorganisms depend on metal compounds that act as final electron acceptors during anaerobic respiration and as electron donors in chemolithotrophic metabolism. In contrast, nonessential metal ions, in particular, and metal ions (both nonessential and essential) at high concentrations, in general, harm the living cell by potentially displacing essential metal ions (in enzymes), competing with structurally related nonmetals in cell reactions and blocking functional groups in biomolecules (29). Therefore, organisms have developed several metal homeostasis and detoxification strategies, including an active efflux system, changes in ion permeability, adsorption, and intra-and extracellular complexation, biotransformation, and compartmentation (10,21,27,31,36).Adsorption of metals by cell wall components is one of the more important interaction mechanisms, and it has been the subject of many studies (for review, see references 3, 15, 20, 34, 35, and 40). Several recent investigations have used surface complexation models (SCMs) to describe the extent of metal adsorption by bacteria as important physical, chemical, and biological parameters are independently varied (5,8,14,16,19,23,43). These SCMs are based upon a set of molecular-scale thermodynamic reactions, each describing adsorption of a particular dissolved chemical species to a particular type of cell wall functional group using a single stability constant, K. Some previous investigations indicate that different bacterial species display similar types of reactive surface functional groups (e.g., carboxyl, phosphoryl, hydroxyl, or ...

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Section: Discussionsupporting

confidence: 91%

Section: Discussionmentioning

confidence: 89%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Cadmium Ion Biosorption by the Thermophilic Bacteria Geobacillus stearothermophilus and G. thermocatenulatus

Hetzer

Daughney

Morgan

2006

Appl Environ Microbiol

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“…In the water-rock systems, bacteria can conduct adsorption reaction due to their extremely high surface area to volume rate and the presence of specific cell wall functional groups [4][5][6][7][8]. Heavy metal pollution in waters has been the most pervasive environmental issues nowadays.…”

Section: Introductionmentioning

confidence: 99%

Characteristic features of Bacillus cereus cell surfaces with biosorption of Pb(II) ions by AFM and FT-IR

Pan

Liu

et al. 2006

Colloids and Surfaces B: Biointerfaces

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In order to elucidate the potential mechanisms involved in the biosorption of metal ions, atomic force microscopy (AFM) and Fourier transform infrared (FT-IR) spectroscopy were used to characterize the interaction between Pb 2+ and Bacillus cereus. AFM imaging of the biomass surfaces exposed to different concentrations of lead ions solution showed a major morphological change occurred after Pb 2+ biosorption. The FT-IR spectra indicated the binding characteristics of the lead ions involved the carboxyl, hydroxyl and amino groups in the biomass. Equilibrium biosorption experiments of Pb 2+ were carried out to investigate the effects of pH values and the initial metal concentrations. The experimental isotherm data were then modeled using Langmuir, Freundlich, and Redlich-Peterson isotherm equations. As a result, the Redlich-Peterson model yielded the best fit of experimental data. Kinetics experiments showed the biosorption was a rapid process and the pseudo-second-order model was successfully applied to predict the rate constant of biosorption.

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Growth and Some Enzymatic Responses ofE. Colito Photocatalytic TiO₂

Chou

Erdem

Huang

et al. 2008

Nanoscience and Nanotechnology

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The effects of photocatalytic nano-TiO 2 on the survival or die-off of E coli (e.g. TB1) were investigated under ambient conditions. Experimentally, 18-h E. coli culture was exposed to photocatalytic nano-TiO 2 at various c oncentrations, e.g., 0 to 1,000 mg/L and particle sizes, e.g., 3 to 55 nm both in darkness and the presence of several light sources including a simulated solar light. Preliminary results indicated that there was bacteria die-off in the presence of nanoscale TiO 2 in dark. Generally it appears that the growth rate decreases as the particle size decreases. The presence of light irradiation significantly enhanced the killing of E. coli due to additional photocatalytic activity. Upon exposure of E. coli to nano-TiO 2 the photocatalytic activity that was generated has markedly increased the production of MDA, TTC and GST. SEM observations vividly indicate cell wall damages.

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The effect of growth phase on proton and metal adsorption by Bacillus subtilis

Cited by 135 publications

References 40 publications

Cadmium Ion Biosorption by the Thermophilic Bacteria Geobacillus stearothermophilus and G. thermocatenulatus

Cadmium Ion Biosorption by the Thermophilic Bacteria Geobacillus stearothermophilus and G. thermocatenulatus

Characteristic features of Bacillus cereus cell surfaces with biosorption of Pb(II) ions by AFM and FT-IR

Growth and Some Enzymatic Responses ofE. Colito Photocatalytic TiO₂

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The effect of growth phase on proton and metal adsorption by Bacillus subtilis

Cited by 135 publications

References 40 publications

Cadmium Ion Biosorption by the Thermophilic Bacteria Geobacillus stearothermophilus and G. thermocatenulatus

Cadmium Ion Biosorption by the Thermophilic Bacteria Geobacillus stearothermophilus and G. thermocatenulatus

Characteristic features of Bacillus cereus cell surfaces with biosorption of Pb(II) ions by AFM and FT-IR

Growth and Some Enzymatic Responses ofE. Colito Photocatalytic TiO2

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Growth and Some Enzymatic Responses ofE. Colito Photocatalytic TiO₂