Microbial Reduction of Iron, Manganese, and other Metals
Section snippets
INTRODUCTION
Microbial reduction of metals and metalloids greatly influences the geochemistry of these materials and affects a variety of other soil properties. In soils and sediments, the reduction of other inorganic electron acceptors such as nitrate, sulfate, and carbon dioxide is a well-known enzymatically catalyzed redox process that is carried out by microorganisms that have specifically evolved to use these compounds (Zehnder and Stumm, 1988). In contrast, metal reduction is often regarded as a
Fe(III) AND Mn(IV) REDUCTION
The most important geochemical change that takes place in many submerged soils and aquatic sediments is the reduction of Fe(III) to Fe(II) (Ponnamperuma, 1972). As discussed in detail in the next section, the reduction of Fe(III) and Mn(IV) not only greatly influences iron and manganese geochemistry but it can also have a dramatic influence on a host of other important soil properties.
URANIUM REDUCTION
The reduction of U(VI) to U(IV) under anoxic conditions greatly affects uranium mobility in water-saturated soils and sediments. The predominant natural forms of uranium are U(VI) and U(IV) (Langmuir, 1978). U(VI), which readily forms strong complexes with dissolved inorganic carbon, is much more soluble than U(IV). Reductive precipitation of uranium sequesters U(IV) in anoxic marine sediments and is the most globally significant sink for dissolved uranium (Veeh, 1967, Cochran et al., 1986,
SELENIUM REDUCTION
There is intense interest in microbial reduction of selenium because although this metalloid is a minor element in most environments, it may accumulate to toxic levels in some soils and waters (Oremland, 1994). Selenium contamination is associated with metal refining (Nriagu and Wong, 1983), fly ash waste (Adriano et al., 1980),and agricultural drainage waters in the western United States, most notably the highly publicized Kesterson National Wildlife Refuge (Presser et al., 1984, Weres et al.,
CHROMATE REDUCTION
Most of the chromium in the environment is in the form of Cr(III). High concentrations of Cr(VI) are usually the result of pollution (Bartlett, 1991, Palmer and Wittbrodt, 1991). Cr(VI) is highly soluble, toxic, and a carcinogen (Richard and Bourg, 1991, Baruthio, 1992). Cr(III) forms insoluble oxides and hydroxides in most natural waters (Palmer and Wittbrodt, 1991, Richard and Bourg, 1991) and is less toxic than Cr(VI) (Petrilli and Flora, 1977). The high midpoint potential of the
MICROBIAL REDUCTION OF OTHER METALS
As reviewed by Lovley (1993), microorganisms are also able to catalyze the reduction of other metals such as technetium, vanadium, molybdenum, copper, gold, and silver. However, investigations into these processes have been rather preliminary with little information of their potential significance in natural environments.
Probably the most intensively studied form of microbial metal reduction is the reduction of soluble Hg(II) to volatile Hg(0) that is carried out by aerobic microorganisms as a
CONCLUSIONS
Microorganisms can enzymatically catalyze the reduction of a large number of metals. For abundant metals such as Fe(III) and Mn(IV), microorganisms have evolved specific metabolic systems which permit them to conserve energy to support growth by coupling the oxidation of organic matter to metal reduction. Microbial Fe(III) reduction accounts for most of the Fe(III) reduction in many anoxic soils and aquatic sediments. Nonenzymatic processes such as the reduction of Fe(III) by organic compounds
REFERENCES (326)
Diagenetic processes near the sediment-water interface of Long Island Sound. II. Fe and Mn
- et al.
Diagenesis of Fe and S in Amazon inner shelf muds: Apparent dominance of Fe reduction and implications for the genesis of ironstones
Cont. Shelf Res.
(1986) - et al.
Complete oxidation of solid phase sulfides by manganese and bacteria in anoxic marine sediments
Geochim. Cosmochim. Acta
(1988) - et al.
Concentration, oxidation state, and particulate flux of uranium in the Black Sea
Geochim. Cosmochim. Acta
(1989) - et al.
Uranium deposition in Saanich Inlet sediments, Vancouver Island
Geochim. Cosmochim. Acta
(1989) - et al.
Modern marine sediments as a natural analog to the chemically stressed environment of a landfill
J. Hydrol.
(1979) - et al.
Crude oil in a shallow sand and gravel aquifer: 3. Biogeochemical reactions and mass balance modeling in anoxic ground water
Appl. Geochem.
(1993) - et al.
Anaerobic reduction of ferric iron by hydrogen bacteria
Microbiology
(1980) Chromium cycling in soils and water: Links, gaps, and methods
Environ. Health Perspect.
(1991)- et al.
Effects of manganese oxide mineralogy on microbial and chemical manganese reduction
Geomicrobiol. J.
(1992)
A pore water/solid phase diagenetic model for manganese in marine sediments
Am. J. Sci.
The anaerobic degradation of organic matter in Danish coastal sediments: Fe reduction, Mn reduction, and sulfate reduction
Geochim. Cosmochim. Acta
Expression of the gene encoding cytochrome c3 from the sulfate-reducing bacterium Desulfovibrio vulgaris into the purple photosynthetic bacterium Rhodobacter sphaeroides
Arch. Biochem. Biophys.
Bacterial interactions with chromate
Antonie van Leeuwenhoek
Reactive iron in marine sediments
Geobacter hydrogenophilia, a dissimilatory Fe(III) reducer capable of oxidizing H2 and formate as well as acetate
Is Fe3+/2+ cycling an intermediate in sulphur oxidation by Fe2+-grown Thiobacillus ferrooxidans?
FEMS Microbiol. Lett.
Biogeochemistry of manganese- and iron-rich sediments in Toolik Lake, Alaska
Hydrobiology
Chromate reduction in Streptomyces
Experientia
On the reduction of manganese peroxide in sewage
Sci. Proc. R. Dublin Soc.
Utilization and disposal of fly ash and other coal residues in terrestrial ecosystems: A review
J. Environ. Qual.
Elution of selenium from contaminated evaporation pond sediments
J. Environ. Qual.
Bioturbation and manganese cycling in hemipelagic sediments
Philos. Trans. R. Soc. London Ser. A
A biological reduction method for removing free iron oxides from soils and colloidal clays
J. Am. Soc. Agron.
Biological and chemical selenium removal from precious metals solutions
Redox behavior of uranium in an anoxic marine basin
Uranium
Biochemistry of Iron in Soil
Inhibitor studies of dissimilative Fe(III) reduction by Pseudomonas sp. Strain 200 (“Pseudomonas ferrireductans”)
Appl. Environ. Microbiol.
Reductive dissolution of Fe(III) oxides by Pseudomonas sp. 200
Biotech. Bioeng.
Regulation of dissimilatory Fe(III) reduction activity in Shewanella putrefaciens
Appl. Environ. Microbiol.
Relation of electrochemical potentials and iron content to ground-water flow patterns
The reductive reactions of Thiobacillus ferrooxidans on sulphur and selenium
FEMS Microbiol. Lett.
Genes encoding mercuric reductases from selected gram-negative aquatic bacteria have a low degree of homology with merA of transposon Tn501
Appl. Environ. Microbiol.
Environmental significance of the potential for mer(Tn21)-mediated reduction of Hg2+ to Hg0 in natural waters
Appl. Environ. Microbiol.
The relationships of Hg(II) volatilization from a freshwater pond to the abundance of mer genes in the gene pool of the indigenous microbial community
Microb. Ecol.
Uranium geochemistry in estuarine sediments: Controls on removal and release processes. Geochim. Cosmochim
Acta
Toxic effects of chromium and its compounds
Biol. Trace Element Res.
Millimeter-scale variations of stable isotope abundances in carbonates from banded iron-formations in the Hamersley Group of Western Australia
Econ. Geol.
Reduction of inorganic compounds by soil microorganisms
Soil Sci. Soc. Amer. Proc.
Anaerobic magnetite production by a marine, magnetotactic bacterium
Nature
Modelling the processes of organic matter degradation and nutrients recycling in sedimentary systems
Chemical transformation of toxic metals by a Pseudomonas strain from a toxic waste site
Environ. Toxicol. Chem.
Magnetotactic bacteria
Annu. Rev. Microbiol.
Some observations on gleying
J. Soil Sci.
Chromate resistance and reduction in Pseudomonas fluorescens strain LB300
Arch. Microbiol.
Some pH-controlling redox reactions in naturals waters
Uranium, vanadium, and molybdenum in saline waters of California
J. Environ. Qual.
Effects of added organic matter on iron and manganese redox systems in sediment
Geomicrobiol. J.
Biological methods to remove selected inorganic pollutants from uranium mine wastewater
Reduction of ferric compounds by soil bacteria
J. Gen. Microbiol.
The reduction of iron oxide by bacteria
J. Soil. Sci.
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