Possible artefactual basis for apparent bacterial growth at 250 degrees C.

Baross and Deming reported that thermophilic marine bacteria isolated from the vicinity of a submarine hot-spring grow at temperatures up to at least 250 degrees C. They did not, however, conduct the appropriate control experiments to eliminate the possibilities of chemical artefacts or contamination. Here, in experiments using the same growth medium, the same temperature and pressure apparatus and the same sampling and analytical procedures, we report results nearly identical to theirs. We conclude that their evidence indicating bacterial growth at 250 degrees C may be due to artefacts produced in the medium and to contaminants introduced during sample processing.