Methane oxidation, microbial

A few examples of chemoautolithotrophic processes have been mentioned in this chapter, namely anaerobic methane oxidation coupled to sulfate reduction and the ones listed in Table 12.2 involving manganese, iron, and nitrogen. Another example are the microbial metabolisms that rely on sulfide oxidation. Since sulfide oxidation is a source of electrons, it is a likely source of energy that could be driving denitrification, and manganese and iron reduction where organic matter is scarce. 

Calculate the steady-state output trichloroethene concentration (/tM) after the methanotrophs have increased their biomass to a steady state level (cell-m-3) assuming a tank with a volume of either V= 10 m3 or 50 m3. Assume you have a waste water flow, Q, of 5 m3 d l, a microbial inoculum with growth properties like those shown in Table 17.6 for the landfill-derived methane oxidizers, and a die-off coefficient b of 0.1 d . 

Topp, E., and Hanson, R.S. (1991) Metabolism of a radiatively important trace gas by methane-oxidizing bacteria In Microbial Production and Consumption of Greenhouse Gases (Rogers, J.E., and Whitman, W.B., eds.), pp. 71-90, ASM Press, Washington, DC. 

Table 3 Microbial methane oxidation kinetic isotope fractionation factors.

Alperin M. J. and W. S. Reeburgh (1984) Geochemical observations supporting anaerobic methane oxidation. In Microbial Growth on C-1 Compounds (eds. R. Crawford and R. Hanson). American Society for Microbiology, Washington, DC, pp. 282-289. 

Barker J. F. and Fritz P. (1981) Carbon isotope fractionation during microbial methane oxidation. Nature 293, 289-291. 

A second newly recognized group of prokaryotes are the methane oxidizing archea. Nearly 90% of the methane produced in anoxic marine sediments is recycled through anaerobic microbial oxidation processes (Cicerone and Oremland, 1988 Reeburgh et al., 1991). However, the organisms and biochemical processes responsible for the anaerobic oxidation of methane (AMO)... 

Hoehler T. M. and Alperin M. J. (1996) Anaerobic methane oxidation by a methanogen-sulfate reducer consortium geochemical evidence and biochemical considerations. In Microbial Growth in Cl Compounds (eds. M. E. Lindstrom and F. R. Tabita). Kluwer Academic, San Diego. 

Sprensen K. B., Finster K., and Ramsing N. B. (2001) Thermodynamic and kinetic requirements in anaerobic methane oxidizing consortia exclude hydrogen, acetate, and methanol as possible electron shuttles. Microbial. Ecol. 42, 1-10. 

Thiel V., Peckmann J., Richnow H. H., Luth U., Reitner J., and Michaelis W. (2001) Molecular signals for anaerobic methane oxidation in Black Sea seep carbonates and a microbial mat. Mar. Chem. 73, 97-112. 

Valentine D. L. (2002) Biogeochemistry and microbial ecology of methane oxidation in anoxic environments a review. Antonie Van Leeuwenhoek 81, 271—282. 

King G. M. (1992) Ecological aspects of methane oxidation, a key determinant of global methane dynamics. laAdvances in Microbial Ecology (ed. K. C. Marshall). Plenum, New York, vol. 12, pp. 431-468. 

Within this setting, in shallow coastal water conditions, consortia of bacteria set up microbial mat columns to exploit the supply of sulphate and nitrate from water. In the muds below the mats, methanogens were active, and above them methane-oxidizing bacteria. The waters were enriched chemically by contributions from hydro-thermal water plumes, either from the laterally equivalent beginnings of Reliance Fm volcanism elsewhere in the basin, or from more distant oceanic sources. Photosynthetic green sulphur bacteria may have oxidized H2S to S°, whereas sulphate and sulphur reducers operated in the reverse direction. 

The rhizosphere is home to a diverse microbial community, including aerobic heterotrophs (Gilbert and Frenzel, 1998), methane oxidizers (Bosse and Frenzel, 1997 Calhoun and King, 1997), and ammonium and nitrite oxidizers (Bodelier et al., 1996 Arth et al., 1998). Microscopy has also shown that microbial cells are associated with Fe plaque (Trolldenier, 1988 St-Cyr et al., 1993), but visual examinations alone cannot determine if cells are responsible for plaque formation. Trolldenier (1988) demonstrated that rusty-colored colonies formed when root plaque was inoculated into an iron-containing medium, but further characterization of these colonies was not attempted. 

Hansen, L.B., Finster, K., Fossing, H. and Iversen, N. (1998) Anaerobic methane oxidation in sulfate depleted sediments effects of sulfate and molybdate additions. Aquatic Microbial Ecology, 14, 195-204. 

Other types of microbial processes may also be important in the subsurface (Table 8.2). Microorganisms, such as sulphate-reducers have also been cultured from low-temperature fluids, and cell morphologies indicative of sulphide-, iron-and methane-oxidizing microorganisms (and protozoa) have been observed in vent fluids (e.g. Holden etal., 1998). Heterotrophs are also present at hydro-thermal vents, though little is known about their abundance and distribution, or... 

In situ microbial production is potentially the most important source of organic C to buoyant and especially neutrally buoyant plumes (Lilley etal., 1995 Winn etal., 1995 Cowen etal., 2001). However, plume productivity is poorly constrained only limited simultaneous measurements of substrate oxidation rates and C02 incorporation rates have been made in hydrothermal plumes for key substrates. For example, rates of dark C02 assimilation and methane oxidation in plumes from the Manus and Lau basins were found to be relatively high (1200-2500ngC-1 day-1 and 1300ngC 1day 1, respectively), but dropped considerably with increasing distance from the vents (Lein etal., 1997). 

Fig. 8.7 Fluorescence in situ Hybridisation (FISH) overlay image of microbial aggregate involved in anaerobic methane oxidation. Different microbes were stained using different oligonucleotide probes. Core is ANNM-2 Archaea, surrounded by sulphate-reducing Desulfosarcina imaged by laser scanning confocal microscopy. From V.J. Orphan etal. in Proc. Natl. Acad. Set USA, Vol. 99, 7663—7668, 2002. Reproduced with permission. Copyright National Academy of Sciences (2002).

Microbial processes could also lead to episodic carbonate dissolution as C02 produced during methanogenesis and methane oxidation could lower the... 

In comparison to all other heterotrophs, the microorganisms oxidizing methane and other Cj compounds such as methanol, have a unique metabolic pathway which involves oxygenase enzymes and thus requires O. Only aerobic methane-oxidizing bacteria have been isolated and studied in laboratory culture, yet methane oxidation in marine sediments is known to take place mostly anaerobically at the transition to the sulfate zone. Microbial consortia that oxidize methane with sulfate have in particular been studied at methane seeps on the sea floor and the communities can now also be grown in the laboratory (Boetius et al. 2000 Orphan et al. 2001 Nauhaus et al. 2002) Anaerobic methane oxidation is catalyzed by archaea that use a key enzyme related to the coenzyme-M reductase of methanogens, to attack the methane molecule (Kruger et al. 2003 see Sect. 5.1). The best studied of these ANME (ANaerobic MEthane... 

The authors of the first edition have revised and substantially updated and enlarged their chapters. We had to give up the partial chapter on sedimentary magnetism of the first edition. In chapter 6 the authors now concentrate on benthic cycles, and the new co-author Heide N. Schulz especially reports on phosphoms cycles and the microbial parts. Chapter 8 was extended to the complete marine sulfur cycling in connection with anaerobic methane oxidation. Gerhard Bohrmann and Marta E. Torres contribute their completely new chapter 14 on methane hydrates in marine sediments, representing a well-rounded presentation of this exciting discipline, which will be of major interest in the future. 

Methane can be removed from estuarine waters by microbial methane oxidation and emission to the atmosphere. Methane oxidation within estuaries can be quite rapid, with methane turnover times of < 2 h to several days. Methane oxidation appears to be most rapid at salinities of less than about 6 (on the practical salinity units scale) and is strongly dependent on temperature, with highest oxidation rates occurring during the summer, when water temperatures are highest. Methane oxidation rates decrease rapidly with higher salinities. 

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