Geochemical diversity in S processes mediated by culture-adapted and environmental-enrichments of Acidithiobacillus spp.

The Importance of Thiosalts Speciation: Review of Analytical Methods, Kinetics, and Treatment

“…There was an overall deficit in total input of sulfur versus measured output of total sulfur, which could potentially indicate trithionate is present. The reaction pathways suggested by Bernier and Warren (2007) in a pH between 2 and 4 is similar to reaction 6.…”

“…At basic conditions, the most likely mechanism is that microorganisms change the oxidation state of sulfur oxidizing thiosulfate to tetrathionate and then to sulfate as reported in reaction 7 (Sorokin and Tourova, 2005). Bernier and Warren (2007) study shows that A. thiooxidans reacts faster than A. ferroxidans and a combination of both microorganism with thiosulfate; also its reaction results on a lower pH of the solution. In addition, their study shows that the stable thiosalt species will depend on the bacteria present in solution.…”

“…However, the main objective of the study was to determine key inhibitors to bacterial activity and limiting the amount of acid mine drainage generated. Another comprehensive study with microorganisms such as Acidithiobacillus ferroxidans and Acidithiobacillus thiooxidans is by Bernier and Warren (2007) where kinetic information of thiosulfate and tetrathionate is presented. Bernier and Warren also followed up the changes in pH as a result of the microorganism oxidation and how the different bacteria changed the speciation in the solution.…”

“…The microorganisms also play a role in the formation of thiosulfate or other polythionates from pyrite depending on conditions (Schippers et al, 1996b). Generally, the final product of microbial degradation of thiosulfate is sulfate with tetrathionate as a secondary product (Bernier and Warren, 2007;Gould et al, 2004;Wentzien et al, 1994), however, the generation of trithionate is also possible depending on the type of microorganism (Silver and Dinardo, 1981;Wentzien et al, 1994) according to the following general pathways:…”

Oxygen and sulfur isotope systematics of sulfate produced during abiotic and bacterial oxidation of sphalerite and elemental sulfur

“…can derive metabolic energy from oxidation of S o , but the electrons pass through several steps of the electron transport system (ETS) before they reduce O 2 to water in the final step (Ehrlich, 1982). The following bacterial oxidation pathway is proposed where S o is first oxidized to sulfite as shown in reaction (9) (Kelly, 1982;Suzuki et al, 1992Suzuki et al, , 1994Bernier and Warren, 2007):…”