Germination of wild-type and ΔgerD spores by high pressures. Wild-type (PS832) and ΔgerD (FB62) spores were germinated with pressure, and spore germination was assessed by measuring DPA release as described in Materials and Methods. ○, wild-type spores germinated with 150 MPa of pressure; •, wild-type spores germinated with 500 MPa of pressure; ▵, ΔgerD spores germinated with 150 MPa of pressure; ▴, ΔgerD spores germinated with 500 MPa of pressure.