AimsTo investigate impact of sporulation and compost temperatures on feasibility of composting for disposal of carcasses contaminated with Bacillus anthracis. Methods and ResultsTwo strains of B.cereus, 805 and 1391, were sporulated at either 20 or 37 degrees C (Sporulation temperature, ST) and 7Log(10)CFUg(-1) spores added to autoclaved manure in nylon bags (pore size 50m) or in sealed vials. Vials and nylon bags were embedded into compost in either a sawdust or manure matrix each containing 16 bovine mortalities (average weight 61733kg), retrieved from compost at intervals over 217days and survival of B.cereus spores assessed. A ST of 20 degrees C decreased spore survival by 14log(10)CFUg(-1) (P<005) compared to a 37 degrees C ST. Spore survival was strain dependent. Compost temperatures >55 degrees C reduced spore survival (P<005) and more frequently occurred in the sawdust matrix. ConclusionsSporulation and compost temperatures were key factors influencing survival of B.cereus spores in mortality compost. Significance and Impact of the studyComposting may be most appropriate for the disposal of carcasses infected with B.anthracis at ambient temperatures 20 degrees C under thermophillic composting conditions (>55 degrees C).