Efficacy of Moist Heat Sterilization is tested by using the Spores of: (A) Bacillus stearothermophilus, (B) Clostridium tetani, (C) Bacillus subtilis, (D) Clostridium botulinum
Answer is A. (A) Bacillus stearothermophilus > For determining the efficacy of moist heat sterilization, (e.g. autoclaving), spores of Bacillus stearothermophilus are used as the test organism. This a thermophilic organism with an optimum growth temp. 55-60degC. Its spores are killed at 121 degC after 12 min exposure.