A new extremely thermophilic,sulfur-reducing heterotrophic,marine bacterium

An extremely thermophilic (optimum growth at 88° C), anaerobic bacterium was isolated from a shallow submarine thermal spring. It appears to be an obligate heterotroph, capable of reducing sulfur to H₂S. Oxygen sensitivity is apparent only at and above those temperatures where growth occurs, while the cultures retain their viability for long periods under air at 4° C. Insensitivity to chloramphenicol, vancomycin and streptomycin, and lack of muramic acid in its cell wall, indicate a possible affilitation of the new isolate to the thermoacidophilic archaebacteria. However, its neutrophilic and hetertrophic nature, as well as its DNA base composition (39.1 mol % guanine plus cytosine) set it apart from the known genera of this group.Abbreviations ASW Artifical sea water medium - Bis-tris propane 1,3-bistris(hydroxymethyl)-methylamino]-propane - Mes 2(N-morpholino)ethanesulfonic acid - Pipes Piperazine-N,N-bis(2-ethanesulfonic acid)