Bacillus endospore resistance to gas dynamic heating

To develop a novel laboratory procedure for the study of shock wave induced damage to Bacillus endospores. Bacillus atrophaeus endospores are nebulized into an aerosol, loaded into the stanford aerosol shock tube and subjected to shock waves of controlled strength. Endospores experience uniform test temperatures between 500 and 1000 K and pressures ranging from 2 to 7 atm, for a relatively short time (2¿3 ms). During this process, the bioaerosol is observed using in situ laser absorption and scattering diagnostics. Additionally, shock-treated samples are extracted for ex situ analysis including viability plating, flow cytometry and SEM imaging. Measurements indicate that endospores lose the ability to form colonies when heated to test temperatures above 500 K while significant breakdown in morphology is observed at test temperatures above 750 K.