Environmental Engineering Reference
In-Depth Information
Table 6.2
Role of trace elements in acetogenic and methanogenic pathways
Trace element Comment
Probable enzyme function
References
Iron
Present in methanogenic tissue in concentrations higher
than any other metal. It plays numerous roles in
anaerobic processes, primarily due to its extremely large
reduction capacity. Iron may form sulphide precipitates,
but may also promote excretion of extra-cellular polymers
which can have a chelating action
Clusters with Ni and S to
make subunits of enzymes
such as hydrogenase, acetyl-
CoA synthase, carbon
monoxide dehydrogenase
(CODH) and formyl MF
dehydrogenase
Brock
., 1984
Kayhanian and Rich, 1995
Schattauer et al., 2011
Somitsch, 2007
et al
Cobalt
Has been shown to be beneficial in many situations
including methylotrophic conversion, and is also
important to acetoclastic and hydrogenotrophic routes
Required for the synthesis of
vitamin B12 which is
essential in functioning of
coenzyme M methylase.
Essential for
methyltransferase. In
acetogenesis, essential in
CODH
Burgess
., 1999
Kayhanian and Rich, 1995
Kida
et al
., 2001
Oleszkiewicz and Sharma,
1990
Schattauer
et al
., 2011
Schonheit and Thauer, 1979
Somitsch, 2007.
et al
Nickel
The nickel tetrapyrrole coenzyme F430 is known to bind to
methyl-S-CoM reductase, which catalyses methane
formation in both acetoclastic and hydrogenotrophic
methanogens. F430 has been found in all known
methanogens. In addition, carbon monoxide
dehydrogenase (CODH) contains a nickel protein and is
involved in acetogenic pathways for both methanogenic
and sulphur-reducing bacteria. Ni stabilises DNA and
RNA, and is a cofactor of urease
The role of Ni in
methanogenesis is related to
the following enzymes:
methylreductase,
hydrogenases and synthesis
of F430. In acetogenesis,
essential in carbon
monoxide dehydrogenase
CODH
Diekert
., 1981
Kayhanian and Rich, 1995
Kida
et al
., 2001
Oleszkiewicz and Sharma,
1990
Somitsch, 2007
Speece, 1983
Thauer
et al
et al
., 1980
Zellner
et al
., 1987
Selenium
Selenium is a component in several anaerobic prokaryotic
enzymes and certain nucleic acids. Selenium-dependent
Formate dehydrogenase
(FDH)
Kayhanian and Rich, 1995
Somitsch, 2007.
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