1. Postgate, J. R. The Sulphate-reducing Bacteria 2nd edn (Cambridge University Press, 1984).
2. Widdel, F. & Pfennig, N. Arch. Microbiol. 129, 395–400 (1981).
3. Schmidt, M. in Sulfur, its Significance for Chemistry, for the Geo, Bio and Technosphere and Technology (eds Müller, A. & Krebs, B.) 259–276 (Elsevier, Amsterdam, 1984).
4. Belkin, S., Wirsen, C. O. & Jannasch, H. W. Appl. Environ. Microbiol. 49, 1057–1061 (1985).
5. Bak, F. & Pfennig, N. Arch. Microbiol. (in the press).