• 1
    Lloyd, D.L. and Jenkinson, D.S. (1995) The exchange of trace gases between land and atmosphere. Trends Ecol. Evol. 10, 13.
  • 2
    Ritchie, D.A., Edwards, C., McDonald, I.R. and Murrell, J.C. (1997) Detection of methanogens and methanotrophs in natural environments. Global Change Biol. (in press).
  • 3
    Mooney, H.A., Vitousek, P.M. and Matson, P.A. (1987) Exchange of materials between terrestrial ecosystems and the atmosphere. Science 238, 926932.
  • 4
    Kudo, Y., Nakajima, T., Miyaki, T. and Oyaizu, H. (1997) Methanogen flora of paddy fields in Japan. FEMS Microbiol. Ecol. 22, 3948.
  • 5
    MacGregor, B.J., Moser, D.P., Alm, E.W., Nealson, K.H. and Stahl, D.A. (1997) Crenarchaeota in Lake Michigan Sediment. Appl. Environ. Microbiol. 63, 11781181.
  • 6
    Head, I.M., Saunders, J.R. and Pickup, R.W. (1993) Microbial evolution, diversity and ecology: a decade of ribosomal RNA analysis of uncultured micro-organisms. Microbiol. Ecol. 35, 121.
  • 7
    Selenska, S. and Klingmuller, W. (1991). DNA recovery and direct detection of Tn5 sequences from soil. Lett. Appl. Microbiol. 13, 21–24.
  • 8
    Hales, B.A., Edwards, C., Ritchie, D.A., Hall, G., Pickup, R.W. and Saunders, J.R. (1996) Isolation and identification of methanogen-specific DNA from blanket bog peat using PCR amplification and sequence analysis. Appl. Environ. Microbiol. 62, 668675.
  • 9
    Felsenstein, J. (1995) Confidence limits on phylogenies: an approach using the bootstrap. Evolution 39, 783–791
  • 10
    Saitou, N. and Nei, M. (1987) The neighbour joining method: a new method for constructing phylogenetic trees. Mol. Biol. Evol. 4, 406425.
  • 11
    Jukes, T.H. and Cantor, C.R. (1969) Evolution of protein molecules. In: Mammalian protein metabolism, Vol. 3 (Munro, H.N. and Allison, J.B., Eds.), pp 21–132. Academic Press, New York.
  • 12
    Springer, E., Sachs, M.S., Woese, C.R. and Boone, D.R. (1995) Partial gene sequences for the A subunit of methyl-coenzyme M reductase (mcrI) as a phylogenetic tool for the Family Methanosarcinaceae. Int. J. Syst. Bacteriol. 45, 554559.
  • 13
    Lehmacher, A. and Klenk, H.-P. (1994) Characterisation and phylogeny of mcrII, a gene encoding an isoenzyme of methyl coenzyme M reductase from hyperthermophilic Methanothermus fervidus. Mol. Gen. Genet. 243, 198206.
  • 14
    Kuske, C.R., Barns, S.M. and Busch, J.D. (1997) Diverse uncultivated bacterial groups from soils of the arid Southwestern United States that are present in many geographic regions. Appl. Environ. Microbiol. 63, 36143621.