Production of Stable Bacillus stearothermophilus Spores

Abstract

A technique has been developed for production of a stable suspension of spores of Bacillus stearothermophilus var. calidolactis. The organism was grown in a sporulating medium on a rotary shaker at 55°C. After 4–5 d, spores were centrifuged and washed to obtain a clear spore suspension, which was able to detect as low as 0.008 I.U./ml of penicillin in 2 h. The spore suspension retained its viability up to 5 months.