archæbacterium Bacteriol.
(ɑːkɪbækˈtɪərɪəm)
Also archæobacterium (rare) and with capital initial. Pl. -bacteria.
[f. archæo- + bacterium.]
Any of a diverse group of micro-organisms similar to ordinary bacteria in size and simplicity of structure, but radically different in their molecular organization.
| 1977 Woese & Fox in Proc. Nat. Acad. Sci. LXXIV. 5089/1 There exists a third kingdom which, to date, is represented solely by the methanogenic bacteria, a relatively unknown class of anaerobes that possess a unique metabolism based on the reduction of carbon dioxide to methane... The apparent antiquity of the methanogenic prototype plus the fact that it seems well suited to the type of environment presumed to exist on earth 3–4 billion years ago lead us tentatively to name this urkingdom the archaebacteria. 1978 Jrnl. Molecular Evol. XI. 246 The archaebacteria include anaerobes, aerobes, autotrophs, heterotrophs, thermophiles, acidophiles, and even photosynthetics... They can be rods, cocci, sarcinae, and spirilla. 1981 Nature 1/8 Jan. 95/2 The archaebacteria are a group of prokaryotes which seem as distinct from the true bacteria (eubacteria) as they are from eukaryotes. 1983 Ibid. 2 June 381/3 The new bacteria, like other extreme thermophiles, are probably archaebacteria, organisms which, with a long separate evolution from the more cosmopolitan eubacteria, have membranes based on a different design—long-chain ether lipids that span from one surface to the other. 1984 Holt & Krieg Bergey's Man. Systemat. Bacteriol. (ed. 9) I. 32/1 The Archaeobacteria..comprise the methanogens, halobacteria and thermoacidophiles. Ibid. 32/2 The Archaeobacteria are distinguished by a number of specialized characters from the rest of the procaryotes (‘Eubacteria’ has had too many meanings in the past to be a useful term)... But these distinctions are not suitable to kingdom status. 1986 Nature 20 Mar. 220/2 The division of the archaebacteria into two branches, methanogens plus halophiles and sulphur-dependent archaebacteria, had been recognized. |
Hence archæbacˈterial a.
| 1978 Jrnl. Molecular Evol. XI. 247 (heading) The archaebacterial cell wall. 1981 Stackebrandt & Woese in M. J. Carlile et al. Molecular & Cellular Aspects Microbial Evol. 20 Archaebacterial lipids are not of the usual ester-linked, straight-chain variety found in true bacteria and eukaryotes. 1981 Sci. Amer. June 103/1 In the course of the ribosomal-RNA studies another unexpected archaebacterial property emerged, one that was to provide the first clue to the significance of the differences between archaebacteria and true bacteria. 1982 Naturwissenschaften LXIX. 203/2 The increasing evidence for a specific relation between archaebacteria and the eukaryotic cytoplasm could be interpreted to mean that the latter has an archaebacterial origin. |