Analysis of germination. Spores were heat activated at 70°C for 30 min. Activated spores were washed twice with germination buffer (50 mM Tris-HCl, pH 7.5, 10 mM NaCl) and resuspended to an optical density at 580 nm (OD580) of 1.0. Auto-germination was monitored for 20 min. Spores that did not autogerminate were used to conduct the germination assays. Experiments were carried out in 96-well plates (200 l/well) using a Labsystems iEMS 96-well plate reader equipped with a filter with a cutoff of 580 nm (Thermo Electron Corporation, Waltham, MA). Experiments were performed in triplicate on at least two different occasions with no fewer than two different spore preparations. Standard deviations were calculated from at least six independent measurements and were typically below 10%. Spore germination was confirmed in selected samples by microscopic observation of aliquots stained using the SchaefferFulton method. Kinetic readings were carried out every minute for 1 h at 25°C. Spores were germinated with various concentrations of cogerminants (concentration ranges were selected to avoid data clusters in doublereciprocal plots) and are listed accordingly in Fig. 1A to E and Fig. S1 to S5 in the supplemental material.