Bacterial sulphate reduction

Sphalerite from the till displays a range of 534S values from-14.1 to -6.0 per mil with a mean value of -9.0 per mil. These low values are interpreted to be the result of bacterial reduction of coeval seawater sulphate. These values are different than those reported for Mississippi Valley-type deposits in the northern and southern Cordillera, which are dominantly much heavier (Fig. 4). Sulphur isotope values... 

Harrison AG, Thode HG (1958) Mechanism of the bacterial reduction of sulphate from isotope fractionation studies. Trans Faraday Soc. 54 84-96... 

Fritz P, Basharmel GM, Drimmie RJ, Ibsen J, Qureshi RM (1989) Oxygen isotope exchange between sulphate and water during bacterial reduction of sulphate. Chem Geol 79 99-105 Fry B (1988) Food web structure on Georges Bank from stable C, N and S isotopic compositions. Limnol Oceanogr 3 1182-1190... 

Bacterial reduction of sulfate in an anaerobic environment with large isotope fractionation between the residual sulphate and the sulphide is the source of sulphur and sulphide in many deposits. The recognition that many sulphur... 

R. M. (1989) Oxygen isotope exchange between sulphate and water during bacterial reduction of sulphate. Chem. Geol. 79, 99-105. 

Thode H. C., Kleerekoper H., and McElcheran D. (1951) Isotopic fractionation in the bacterial reduction of sulphate. 

Kemp, A.L.W. and Thode, H.G., 1968. The mechanism of the bacterial reduction of sulphate and of sulphite from isotope fractionation studies. Geochim. Cosmochim. Acta, 32 71—91. 

Mizutani, Y. and Rafter, T.A., 1973. Isotopic behaviour of sulphate oxygen in the bacterial reduction of sulphate. Geochem. J., 6 183—191. 

This process is most important in marine sediments where the pore waters contain appreciable amounts of dissolved sulphate. Bacterial sulphate reduction (BSR) operates when the pore waters are devoid of dissolved oxygen (i.e. anoxic). In euxinic basins the sediment experiences BSR diagenesis directly at the sediment-water interface (Fig. 1) in other words, no oxic and suboxic phases are encountered (Curtis, 1987). Sulphate reduction is aided by anaerobic bacteria, as follows ... 

Some isotope fractionations, notably those in biological systems, are primarily controlled by kinetic effects. For example, the bacterial reduction of seawater sulphate to sulphide proceeds 2.2 % faster for the light isotope than for S. -/For the reactions... 

Oxidation-reduction potential Because of the interest in bacterial corrosion under anaerobic conditions, the oxidation-reduction situation in the soil was suggested as an indication of expected corrosion rates. The work of Starkey and Wight , McVey , and others led to the development and testing of the so-called redox probe. The probe with platinum electrodes and copper sulphate reference cells has been described as difficult to clean. Hence, results are difficult to reproduce. At the present time this procedure does not seem adapted to use in field tests. Of more importance is the fact that the data obtained by the redox method simply indicate anaerobic situations in the soil. Such data would be effective in predicting anaerobic corrosion by sulphate-reducing bacteria, but would fail to give any information regarding other types of corrosion. 

McIntyre P.E. Edenborn H.M. 1990. The Use Of Bacterial Sulphate Reduction In The Treatment Of Drainage From Coal Mines. 

Pollard, P.C., and Moriarty, DJ.W. (1991) Organic carbon decomposition, primary and bacterial productivity, and sulphate reduction, in tropical seagrass beds of the Gulf of Carpentaria, Australia. Mar. Ecol. Prog. Ser. 69, 149. 

Mizutani Y. and Rafter T. A. (1969) Oxygen isotopic composition of sulphates Part 4. Bacterial fractionation of oxygen isotopes in the reduction of sulphate and in the oxidation of sulphur. NZ J. Sci. 12, 60—67. 

Spence M. J., Botfrell S. H., Thornton S. E., and fjCmer D. N. (2001) Isotopic modelhng of the significance of bacterial sulphate reduction for phenol attenuation in a contaminated aquifer. J. Contamin. Hydrol. 53, 285—304. 

Schink B. and Friedrich M. (2000) Bacterial metabolism— phosphite oxidation by sulphate reduction. Nature 406(6791), 37-37. 

Parkes R. J., Dowling N. J. E., White D. C., Herbert R. A., and Gibson G. R. (1993) Characterization of sulphate-reducing bacterial populations within marine and estuarine sediments with different rates of sulphate reduction. FEMS Microbiol. Ecol. 102, 235-250. 

Oremland R. S., Dowdle P. R., Hoeft S., Sharp J. O., Schaefer J. K., Miller L. G., Blum J. S., Smith R. L., Bloom N. S., and Wallschlaeger D. (2000) Bacterial dissimilatory reduction of arsenate and sulphate in meromictic Mono Lake, CaUfomia. Geochim. Cosmochim. Acta 64, 3073—3084. 

Sorokin, Y.I., 1962. Experimental investigation of bacterial sulphate reduction in the Black Sea using S. Mikrobiologiya, 31 329—335. 

Spiro, B., 1977. Bacterial sulphate reduction and calcite precipitation in hypersaline deposition of bituminous shales. Nature, 269 235—237. 

In contrast, in shallow reservoirs bacterial sulfate reduction may occur with degradation of the crude oil (Bailey et al., 1973). The sulphate reducers may not be able to use petroleum per se but only with the participation of petroleum-oxidizing aerobes, transported by freshwater recharge, to provide suitable carbon sources for the sulfate-reducers (see Chapter 6.1). 

To summarize, the isotopic and textural evidence collectively implies the activity in the Belingwe belt of a variety of prokaryotic processes (1) sulphate reduction and possibly photosynthetic sulphide oxidation (2) operation of rubisco both in cyanobacterial stromatolites (as expected) but also possibly in non-photosynthetic sulphur-bacterial mats (3) oxygenic photosynthesis (in stromatolites) (4) methanogenesis and methane oxidation. Most probably, other sulphur-based metabolic reactions (e.g. dissim-ilatory sulphate reduction) were also taking place. This complexity is consistent with the relative timing of the metabolic phylogeny deduced from rRNA studies (Woese 1987 Pace 1997). 

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