Resistance of Bacillus endospores to extreme terrestrial and extraterrestrial environments

Endospores of Bacillus spp., especially Bacillus subtilis, have served as e xperimental models for exploring the molecular mechanisms underlying the in credible longevity of spores and their resistance to environmental insults. In this review we summarize the molecular laboratory model of spore resist ance mechanisms and attempt to use the model as a basis for exploration of the resistance of spores to environmental extremes both on Earth and during postulated interplanetary transfer through space as a result of natural im pact processes.