Sulfur oxidizing microorganisms

The colorless sulfur-oxidizing microorganisms include relatives of the bluegreen algae (Beggiaioa and Thiothrix) and a genus of the eubac-teria (Thiobacillus). The latter require iron for growth and presumably synthesize the cytochrome systems (60). 

All of the reactions above (b - e) illustrate how microorganisms on solid phases mediate reactions that can cause or negate pollution. For example, nitrification (reactions b-c) and sulfur oxidation (reactions d-e) can result in the production of specific pollutants, i.e., nitrate and sulfuric acid... 

Oxidation of sulfide will affect rates of sulfate reduction only if sulfate is the end product of such oxidation. Many compounds with oxidation states intermediate between sulfide and sulfate may be formed instead. Although many details of the oxidation pathways remain to be clarified, evidence suggests that sulfate is formed. Oxidation of sulfide by phototrophic microorganisms results in production of elemental sulfur, sulfate, or polythionates (e.g., 171). Members of each of the three families of phototrophic sulfur-oxidizing bacteria are capable of carrying the oxidation all the way to sulfate elemental sulfur and polythionates are intermediates that are stored until lower concentrations of sulfide are encountered (131, 171). Colorless sulfur... 

Identification of the microorganisms found in both the process water and on the metal surface. Tests for nitrite-utilizing bacteria or sulfur oxidizers are more complex. (Stott)5... 

Dugan, P. R. 1987. Prevention of formation of acid drainage from high-sulfur coal refuse by inhibition of iron- and sulfur-oxidizing microorganisms. II. Inhibition in Run of Mine refuse under simulated field conditions. Biotech. Bioeng. 29 49-54. 

Sulfur oxidation produces substantial amounts of H2SO4. The resulting acidification can lead to solubilization of phosphorus and other mineral nutrients in soils with a generally beneficial effect on both microorganisms and plants. 

Vitolins, M.I. and Swaby, R.J., 1969. Activity of sulfur-oxidizing microorganisms in some Australian soils. Aust. J. Soil Res., 7 171—183. 

Degradation of l4C-labelled (1-propyl position) and unlabelled EPTC by the microbial isolate yielded N-depropyl EPTC (a product of a-propyl hydroxylation) and EPTC-sulfoxide (sulfur oxidation). It is proposed that initial reactions of soil microorganisms involve both hydroxylation and sulfoxidation, resulting in products that are further metabolized to C02. The hydroxylation reaction is thought to be dominant when degradation of EPTC occurs at enhanced rates. 

The most serious MIC takes place in the presence of microbial consortia where many types of microorganisms are present within the structure of the biofilm. These include sulfate-reducing bacteria (SRB), sulfur oxidizing bacteria, metal-reducing and metal-oxidizing bacteria, acid-producing and slime-producing bacteria, in addition to other aerobic and anaerobic microbes. 

S in the atmosphere which is present as SO2, H2S, and organic sulfur (DMS, (013)28, CS2, COS etc.) oxidizes easily and removes by rainfall, implying that residence time of sulfur in the atmosphere is short. Activities of microorganism takes important role for short-term sulfur cycle. For example, DMS that is produced by plankton transfers from ocean to atmosphere (Lovelock et al. 1972). This sulfur flux is estimated as (1.9-0.6) x 10 mol year (4 2 x 10 g year ). Activities of bacteria promote oxidation-reductiOTi reactimis in soils and affect the rate of sulfur transfer between soils and soil water. For example, sulfate-reducing bacteria and sulfur-oxidizing bacteria promote the following reactions. 

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