Survival of dried eukaryotes (anhydrobiotes) after exposure to very high temperatures

Abstract

Organisms that tolerate essentially complete dehydration are said to be in anhydrobiosis, and can be referred to as anhydrobiotes. Those organisms are of great ecological and medical importance, but also provide models for the study of a variety of biological phenomena. We examined the tolerance of selected eukaryotic anhydrobiotes to high temperatures using slow (∼4°C min -1) and rapid (∼100°C min-1) heating to 110, 120, 130, and 140°C. Test organisms were then either returned to storage temperatures close to 22°C (preheating), or held at those high temperatures for an additional 10 min. Some anhydrobiotes survived slow heating to 130°C, whereas rapid heating led to a dramatic reduction in survival. None of these organisms encounter anywhere near these high temperatures in nature, so tolerance is not an obvious result of adaptation to current or recent conditions. We speculate that tolerance could have been achieved during the much earlier evolution of these organisms, and has been retained up to the present. © 2008 The Linnean Society of London.