Glass, Jennifer B. and Orphan, Victoria J. (2012) Trace metal requirements for microbial enzymes involved in the production and consumption of methane and nitrous oxide. Frontiers in Microbiology, 3 . Art. No. 61. ISSN 1664-302X http://resolver.caltech.edu/CaltechAUTHORS:20120312-095005613
- Published Version
Creative Commons Attribution Non-commercial.
Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20120312-095005613
Fluxes of greenhouse gases to the atmosphere are heavily influenced by microbiological activity. Microbial enzymes involved in the production and consumption of greenhouse gases often contain metal cofactors. While extensive research has examined the influence of Fe bioavailability on microbial CO_2 cycling, fewer studies have explored metal requirements for microbial production and consumption of the second- and third-most abundant greenhouse gases, methane (CH_4), and nitrous oxide (N_2O). Here we review the current state of biochemical, physiological, and environmental research on transition metal requirements for microbial CH_4 and N_2O cycling. Methanogenic archaea require large amounts of Fe, Ni, and Co (and some Mo/W and Zn). Low bioavailability of Fe, Ni, and Co limits methanogenesis in pure and mixed cultures and environmental studies. Anaerobic methane oxidation by anaerobic methanotrophic archaea (ANME) likely occurs via reverse methanogenesis since ANME possess most of the enzymes in the methanogenic pathway. Aerobic CH_4 oxidation uses Cu or Fe for the first step depending on Cu availability, and additional Fe, Cu, and Mo for later steps. N_2O production via classical anaerobic denitrification is primarily Fe-based, whereas aerobic pathways (nitrifier denitrification and archaeal ammonia oxidation) require Cu in addition to, or possibly in place of, Fe. Genes encoding the Cu-containing N_2O reductase, the only known enzyme capable of microbial N_2O conversion to N_2, have only been found in classical denitrifiers. Accumulation of N_2O due to low Cu has been observed in pure cultures and a lake ecosystem, but not in marine systems. Future research is needed on metalloenzymes involved in the production of N_2O by enrichment cultures of ammonia oxidizing archaea, biological mechanisms for scavenging scarce metals, and possible links between metal bioavailability and greenhouse gas fluxes in anaerobic environments where metals may be limiting due to sulfide-metal scavenging.
|Additional Information:||© 2012 Glass and Orphan. This is an open-access article distributed under the terms of the Creative Commons Attribution Non Commercial License, which permits non-commercial use, distribution, and reproduction in other forums, provided the original authors and source are credited. Received: 05 December 2011; Paper pending published: 21 December 2011; Accepted: 05 February 2012; Published online: 21 February 2012. The authors acknowledge funding from the National Aeronautics and Space Administration (NASA) Astrobiology Postdoctoral Fellowship (to Jennifer B. Glass), the NASA Astrobiology Institute (NNA04CC06A), and the U.S. Department of Energy’s Office of Biological and Environmental Research Early Career Award (to Victoria J. Orphan). Thanks to Roland Hatzenpichler, Patricia Tavormina, Shawn McGlynn, Anne Dekas, Joshua Steele, Hiroyuki Imachi, Lisa Stein and Aubrey Zerkle for helpful comments on drafts of this manuscript.|
|Subject Keywords:||methane, nitrous oxide, microbes, metals, enzymes|
|Official Citation:||lass JB and Orphan VJ (2012) Trace metal requirements for microbial enzymes involved in the production and consumption of methane and nitrous oxide. Front. Microbio. 3:61. doi: 10.3389/fmicb.2012.00061|
|Usage Policy:||This is an open-access article distributed under the terms of the Creative Commons Attribution Non Commercial License, which permits non-commercial use, distribution, and reproduction in other forums, provided the original authors and source are credited.|
|Deposited By:||Tony Diaz|
|Deposited On:||20 Mar 2012 22:17|
|Last Modified:||26 Dec 2012 14:56|
Repository Staff Only: item control page