Importance of Extracellular Polymeric Substances from<i>Thiobacillus ferrooxidans</i>for Bioleaching

Gehrke, T.; Telegdi, J.; Thierry, Dominique; Sand, Wolfgang

doi:10.1128/aem.64.7.2743-2747.1998

Cited by 403 publications

(168 citation statements)

References 23 publications

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“…For the iron oxidizing bacteria A. ferrooxidans growing on ferrous iron a value of 250 6 30 (lg EPS/10 10 cells) was experimentally obtained. 21 Considering a cell weight of 10 213 (g/cell) and a composition of 75% water in the cell weight, a value of f EPS 5 0.86 (g EPS /GDW) is obtained.…”

Section: Specific Reaction Ratesmentioning

confidence: 99%

Characterization of Ferroplasma acidiphilum growing in pure and mixed culture with Leptospirillum ferriphilum

Merino

Andrews

Parada³

et al. 2016

Biotechnology Progress

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Biomining is defined as biotechnology for metal recovery from minerals, and is promoted by the concerted effort of a consortium of acidophile prokaryotes, comprised of members of the Bacteria and Archaea domains. Ferroplasma acidiphilum and Leptospirillum ferriphilum are the dominant species in extremely acid environments and have great use in bioleaching applications; however, the role of each species in this consortia is still a subject of research. The hypothesis of this work is that F. acidiphilum uses the organic matter secreted by L. ferriphilum for growth, maintaining low levels of organic compounds in the culture medium, preventing their toxic effects on L. ferriphilum. To test this hypothesis, a characterization of Ferroplasma acidiphilum strain BRL-115 was made with the objective of determining its optimal growth conditions. Subsequently, under the optimal conditions, L. ferriphilum and F. acidiphilum were tested growing in each other's supernatant, in order to define if there was exchange of metabolites between the species. With these results, a mixed culture in batch cyclic operation was performed to obtain main specific growth rates, which were used to evaluate a mixed metabolic model previously developed by our group. It was observed that F. acidiphilum, strain BRL-115 is a chemomixotrophic organism, and its growth is maximized with yeast extract at a concentration of 0.04% wt/vol. From the experiments of L. ferriphilum growing on F. acidiphilum supernatant and vice versa, it was observed that in both cases cell growth is favorably affected by the presence of the filtered medium of the other microorganism, proving a synergistic interaction between these species. Specific growth rates were obtained in cyclic batch operation of the mixed culture and were used as input data for a Flux Balance Analysis of the mixed metabolic model, obtaining a reasonable behavior of the metabolic fluxes and the system as a whole, therefore consolidating the model previously developed. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1390-1396, 2016.

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Section: Specific Reaction Ratesmentioning

confidence: 99%

Characterization of Ferroplasma acidiphilum growing in pure and mixed culture with Leptospirillum ferriphilum

Merino

Andrews

Parada³

et al. 2016

Biotechnology Progress

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“…This process may explain the accumulation of trace metals at depth, especially in the reactive relative to the pyrite fraction, because formation of iron sulfides is hindered by lack of reactive Fe. Interestingly, Gehrke et al (1998) found that EPS are involved in metal sulfide (e.g., pyrite) dissolution through the attachment of lipopolysaccharide-containing EPS to the sulfide substrate. The process is mediated by exopolymer-complexed Fe(III) ions that allow the establishment of an electrochemical interaction with the negatively charged pyrite surface.…”

Section: Enrichment Factorsmentioning

confidence: 99%

Millimeter‐scale resolution of trace metal distributions in microbial mats from a hypersaline environment in Baja California, Mexico

et al. 2012

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Microbial mats from two ponds with different salinities from the saltern of Guerrero Negro (Mexico) points toward millimeter-scale coherent variations in trace metal (Me) concentrations (Cd, Co, Cu, Fe, Mn, Ni, Pb, Zn). Total, HCl-leachable and pyrite-associated Me showed a trend of increasing concentrations with increasing depth suggesting gradual addition of reactive Me probably as a result of metal sulfide precipitation at depth. The trends in Me profiles can be ascribed to the establishment and maintenance of microzones that promote geochemical processes, bacterial population distributions, and differential mass transport within the mats. Degrees of trace metal pyritization (1 ± 1% for Zn to 24 ± 7% for Cd) as well as metals associated with the pyrite fraction (<1.4-36 ± 18 nmol g(-1) for Zn and Mn, respectively) were low, as expected from a reactive Fe-limited system like Guerrero Negro. Calculated enrichment factors showed that Ni (2.6 ± 2.1), Co (5.5 ± 4.0), Pb (9.4 ± 7.4), and Cd (57 ± 39) were, on average, enriched in the microbial mats of Guerrero Negro. Natural enrichments of Cd, Pb, and Co in sediments along the coast of Baja California and metabolical requirements of Co and Ni by the predominant cyanobacteria in the Guerrero Negro mats may explain these enrichments. Metal characteristics in microbial mats could be advantageously used as biosignatures to identify their presence in the geological record or in other planetary systems.

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“…Growth on sulphide minerals is facilitated by close bacteriamineral interaction (Duncan & Drummond, 1973;Tributsch, 1976;Bennet & Tributsch, 1978;Norman & Snyman, 1987;Rodriguez & Tributsch, 1988;Southam & Beveridge, 1992). It has also been demonstrated that these bacteria are tightly bound to the mineral surface (Gormley & Duncan, 1974;Southam & Beveridge, 1992), via lipopolysaccharides (Southam & Beveridge, 1993;Arrendondo et al ., 1994;Gehrke et al ., 1998) suggesting that this interaction is important to the growth of thiobacilli on sulphides. Even though thiobacilli are closely associated with the sulphide mineral surface, bio-oxidation occurs through an indirect oxidation, in which bacteria utilize soluble reduced iron and sulphur species (Sand et al ., 1995;Nordstrom & Southam, 1997;Fowler & Crundwell, 1998).…”

Section: Introductionmentioning

confidence: 99%

A critical stage in the formation of acid mine drainage: Colonization of pyrite by Acidithiobacillus ferrooxidans under pH‐neutral conditions

et al. 2003

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A dominant Acidithiobacillus ferrooxidans ssp. was isolated from the supergene copper deposit in Morenci, Arizona, USA. Washed bacterial suspensions (108 MPN per treatment), in pH‐neutral buffer, were inoculated onto pyrite cubes for 24 h. Heterogeneous bacterial absorption onto the pyrite removed approximately 90% of the viable bacteria from the inoculum. At T = 0, the bacteria were observed primarily in regions enriched in phosphorus. Over 30 days, the bacterial population on the pyrite cubes increased from 1.3 × 107 to 2.9 × 108 bacteria cm−2. During this growth stage, low levels of thiobacilli (228 ± 167 MPN mL−1) were also recovered from the fluid phase; however, this population decreased to zero within 30 days. Growth on pyrite occurred as micrometre‐scale planar microcolonies, a biofilm, coating the mineral surfaces. These microcolonies possessed viable thiobacilli, even after 4 months at ‘circumneutral pH’. Imaging the pyrite cubes using SEM‐EDS and scanning force microscopy demonstrated that the thiobacilli grew as iron oxy‐hydroxide‐cemented cells, leading to the formation of mineralized microcolonies. Removing the iron oxy‐hydroxides with oxalic acid did not dislodge the bacteria, demonstrating that the secondary minerals were not responsible for ‘gluing’ the bacteria to the pyrite surface. Removing organic material, i.e. the cells, by an oxygen plasma treatment revealed the presence of corrosion pits the size and shape of bacteria. Because of the inherent geochemical constraints on pyrite oxidation at neutral pH, the colonization of pyrite under circumneutral pH conditions must be facilitated by the development of an acidic nanoenvironment between the bacteria and the pyrite mineral surface.

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Importance of Extracellular Polymeric Substances fromThiobacillus ferrooxidansfor Bioleaching

Cited by 403 publications

References 23 publications

Characterization of Ferroplasma acidiphilum growing in pure and mixed culture with Leptospirillum ferriphilum

Characterization of Ferroplasma acidiphilum growing in pure and mixed culture with Leptospirillum ferriphilum

Millimeter‐scale resolution of trace metal distributions in microbial mats from a hypersaline environment in Baja California, Mexico

A critical stage in the formation of acid mine drainage: Colonization of pyrite by Acidithiobacillus ferrooxidans under pH‐neutral conditions

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