title: The use of inhibitors to identify early events during Bacillus megaterium KM spore germination.
abstract: The germination response of spores of Bacillus megaterium KM, as measured by loss of A600, is more than 95% inhibited by 1 mM-HgCl2. Two Hg2+-sensitive sites (referred to as 'sites I and II') have been identified during germination. Site I represents a pre-commitment event and can be protected from HgCl2 by 50 mM-D-alanine, whereas site II represents a post-commitment event and is not D-alanine-protectable. At 1 mM-HgCl2, 25% of the spore population becomes committed to germinate, but an A600 loss of less than 5% occurs. In this system, loss of heat resistance was associated with commitment, whereas selective cortex hydrolysis, release of pyridine-2,6-dicarboxylic acid, Zn2+ and soluble peptidoglycan, as well as loss of refractility, were identified as post-commitment events. The commitment event was reversibly inhibited by several proteinase inhibitors and a membrane bulking agent. A model of spore germination based on these results is presented.
mesh_terms: D000409:Alanine / Q000494:pharmacology; D001410:Bacillus megaterium / Q000187:drug effects / Q000502:physiology*; D001665:Binding Sites; D008627:Mercuric Chloride / Q000494:pharmacology*; D008954:Models, Biological; D013171:Spores, Bacterial / Q000187:drug effects
chemical_list: D008627:Mercuric Chloride; D000409:Alanine