Sulfur-reducing bacteria

On the left: Bioconstructions created by sulfur bacteria in a sulfurous cave at a depth of about 30 mt in Santa Cesarea Terme, Lecce, Italy. On the right: The same bioconstructions suspended in water. These structures are extremely fragile, and even a small air bubble emitted by a diver can disperse them in the water.

Sulfur-reducing bacteria are microorganisms able to reduce elemental sulfur (S0) to hydrogen sulfide (H2S).[1] These microbes use inorganic sulfur compounds as electron acceptors to sustain several activities such as respiration, conserving energy and growth, in absence of oxygen.[2] The final product of these processes, sulfide, has a considerable influence on the chemistry of the environment and, in addition, is used as electron donor for a large variety of microbial metabolisms.[3] Several types of bacteria and many non-methanogenic archaea can reduce sulfur. Microbial sulfur reduction was already shown in early studies, which highlighted the first proof of S0 reduction in a vibrioid bacterium from mud, with sulfur as electron acceptor and H
2 as electron donor.[4] The first pure cultured species of sulfur-reducing bacteria, Desulfuromonas acetoxidans, was discovered in 1976 and described by Pfennig Norbert and Biebel Hanno as an anaerobic sulfur-reducing and acetate-oxidizing bacterium, not able to reduce sulfate.[5] Only few taxa are true sulfur-reducing bacteria, using sulfur reduction as the only or main catabolic reaction.[6] Normally, they couple this reaction with the oxidation of acetate, succinate or other organic compounds. In general, sulfate-reducing bacteria are able to use both sulfate and elemental sulfur as electron acceptors. Thanks to its abundancy and thermodynamic stability, sulfate is the most studied electron acceptor for anaerobic respiration that involves sulfur compounds. Elemental sulfur, however, is very abundant and important, especially in deep-sea hydrothermal vents, hot springs and other extreme environments, making its isolation more difficult.[2] Some bacteria – such as Proteus, Campylobacter, Pseudomonas and Salmonella – have the ability to reduce sulfur, but can also use oxygen and other terminal electron acceptors.

  1. ^ Cite error: The named reference :4 was invoked but never defined (see the help page).
  2. ^ a b Florentino AP, Weijma J, Stams AJ, Sánchez-Andrea I (2016). "Ecophysiology and Application of Acidophilic Sulfur-Reducing Microorganisms". In Rampelotto PH (ed.). Biotechnology of Extremophiles. Grand Challenges in Biology and Biotechnology. Vol. 1. Cham: Springer International Publishing. pp. 141–175. doi:10.1007/978-3-319-13521-2_5. ISBN 978-3-319-13521-2.
  3. ^ Rabus R, Hansen TA, Widdel F (2006). "Dissimilatory Sulfate- and Sulfur-Reducing Prokaryotes". In Dworkin M, Falkow S, Rosenberg E, Schleifer KH, Stackebrandt E (eds.). The Prokaryotes. New York, NY: Springer New York. pp. 659–768. doi:10.1007/0-387-30742-7_22. ISBN 978-0-387-25492-0.
  4. ^ Parker CT, Taylor D, Garrity GM (2003-01-01). Parker CT, Garrity GM (eds.). "Exemplar Abstract for Chlorobium vibrioforme Pelsh 1936 (Approved Lists 1980) and Prosthecochloris vibrioformis (Pelsh 1936) Imhoff 2003". The NamesforLife Abstracts. doi:10.1601/ex.789.
  5. ^ Pfennig N, Biebl H (October 1976). "Desulfuromonas acetoxidans gen. nov. and sp. nov., a new anaerobic, sulfur-reducing, acetate-oxidizing bacterium". Archives of Microbiology. 110 (1): 3–12. doi:10.1007/BF00416962. PMID 1015937. S2CID 9330789.
  6. ^ Stetter KO, Zillig W (1985-01-01). Woese CR, Wolfe RS (eds.). Chapter 2: Thermoplasma and the Thermophilic Sulfur-Dependent Archaebacteria. Academic Press. pp. 85–170. doi:10.1016/b978-0-12-307208-5.50008-8. ISBN 978-0-12-307208-5. {{cite book}}: |work= ignored (help)