The aim of this study is to measure the UV-C inactivation kinetics and determine the fluences required for incremental inactivation of Alicyclobacillus acidoterrestris (AAT). Spores from five strains of AAT (ATCC 49025, DSM 2498, VF, SAC, and WAC) were suspended in clear phosphate-buffered saline (PBS) and individually treated with UV-C doses up to 100 mJ/cm