Methanococcoides burtonii DSM 6242
   
   
 
The majority of the Earth’s biosphere is perpetually below 5 oC, yet comparatively little is known about the physiology and genetics of the microorganisms inhabiting these environments. The mechanisms by which cells adapt to the cold have mostly been gleaned from the cold shock response in mesophilic prokaryotes in the phylogenetic domain Bacteria. The genome sequence of the psychrotolerant methanogen M. burtonii, which is currently scheduled for sequencing in 2002 by the DOE Joint Genome Project, will enable researchers to identify genes that are required for survival and adaptation of these Archaea at cold temperature. To date no genomes have been completed for any cold adapted organisms and the genome sequencing of M. burtonii will provide the first comprehensive insight into the genetic composition required for cold adaptation.

By comparative sequence analysis with methanogen genomes, including those of the mesophile Methanosarcina barkeri (Tmax: 40oC), the thermophile Methanosarcina thermophila (Tmax: 55oC) and the extreme thermophile Methanococcus jannaschii (Tmax: 85oC) it will be possible to identify a subset of genes unique to the cold-adapted methanogen. In silico protein structure comparisons may also highlight adaptive strategies.

In addition to the evolutionary implications inherent with comparing mechanisms of archaeal cold-adaptation with those in Bacteria and Eukarya, completion of the M. burtonii genome sequence will expand our understanding of the organismal and metabolic biocomplexity that has evolved in association with cold-adapted microorganisms. Completing the genomic sequence of this extremophile will contribute to the long-term goal of establishing the global cold-adaptive strategies of microorganisms and defining the boundaries of life on Earth and in extraterrestrial environments.

References

Franzmann, P.D., Springer, N., Ludwig, W., Conway De Macario, E. and Rohde, M. 1992. A methanogenic archaeon from Ace Lake, Antarctica: Methanococcoides burtonii sp. nov. System. Appl. Microbiol. 15: 573-581.

Nichols, P.D. and Franzmann, P.D. 1992. Unsaturated diether phospholipids in the Antarctic methanogen Methanococcoides burtonii. FEMS Microbiol. Lett. 98: 205-208.

Thomas, T. and Cavicchioli, R. 1998. Archaeal cold-adapted proteins: structural and evolutionary analysis of the elongation factor 2 proteins from psychrophilic, mesophilic and thermophilic methanogens. FEBS Lett 439: 281-286.

Thomas, T. and Cavicchioli, R. 2000. Effect of temperature on the stability and activity of the elongation factor 2 proteins from low-temperature adapted and thermophilic methanogens. J. Bacteriol. 182: 1328-1332.

Lim, J., Thomas, T. and Cavicchioli, R. 2000. Low temperature regulated DEAD-box RNA helicase from the Antarctic archaeon, Methanococcoides burtonii. J. Mol. Biol. 297: 553-567.

Cavicchioli, R., Thomas, T. and Curmi, P.M.G. 2000. Cold stress response in archaea. Extremophiles 4: 321-331.

Thomas, T., Kumar, N. and Cavicchioli, R. 2001. Effects of ribosomes and intracellular solutes on activities and stabilities of elongation factor 2 proteins from psychrotolerant and thermophilic methanogens. J. Bacteriol. 183: 1974-1982.

Siddiqui, K.S., Cavicchioli, R. and Thomas, T. 2002. Thermodynamic activation properties of elongation factor 2 (EF-2) proteins from psychrotolerant and thermophilic archaea. Extremophiles Online First: 29 January DOI 10.1007/s007920100237.

Thomas, T. and Cavicchioli, R. 2002. Cold adaptation of archaeal elongation factor 2 (EF-2) proteins. Current Protein and Peptide Science. 3(2) (in press)

Papers with some information

McMeekin, T.A., Nichols, P.D., Juhasz, A. and Franzmann, P.D. 1993. Biology and biotechnological potential of halotolerant bacteria from Antarctic saline lakes. Experientia. 49: 1042-1046.

Nichols PD. Shaw PM. Mancuso CA. Franzmann PD. 1993. ANALYSIS OF ARCHAEAL PHOSPHOLIPID-DERIVED DIRAETHER AND TETRAETHER LIPIDS BY HIGH TEMPERATURE CAPILLARY GAS CHROMATOGRAPHY Journal of Microbiological Methods. 18:1-9.

Franzmann, P.D. 1996. Examination of Antarctic prokaryotic diversity through molecular comparisons. Biodiversity and Conservation.

Summons RE. Franzmann PD. Nichols PD. 1998. CARBON ISOTOPIC FRACTIONATION ASSOCIATED WITH METHYLOTROPHIC METHANOGENESIS. Organic Geochemistry. 28:465-475.

Information about methanogenesis and archaeal lipid biomarkers

Franzmann, P.D., Roberts, N.J., Mancuso, C.A., Burton, H.R. and McMeekin, T.A. 1991. Methane production in meromictic Ace Lake, Antarctica. Hydrobiologia. 210: 191-201.

Mancuso, C.A., Franzmann, P.D., Burton, H.R. and Nichols, P.D. 1990. Microbial community structure and biomass estimates of a methanogenic Antarctic Lake ecosystem as determined by phospholipid analyses. Microbial Ecology. 19: 73-95.