In silico analysis of Bacillus stearothermophilus as a bioindicator for sterilizationco analysis of Bacillus stearothermophilus as a bioindicator for sterilization

To kill every kind of viable bacterial cells, sterilization in food and pharmaceutical industries is essential. In this study, bio indicators are used to validate accurate sterility. Bacillus stearothermophilus is used as a reference standard heat stable bio indicator. A 16S ribosomal RNA ribotyping sequence of Bacillus stearothermophilus is compared with different bacterial bioindicators including Bacillus pumilus, Bacillus atrophaeus, Clostridium sporogenes, and Brevundimonas diminuta. Results showed that Bacillus pumilus has the highest percentage (90.88%) similarity with the Geobacillus stearothermophilus followed by the Bacillus atrophaeus (90.84%), and Clostridium sporogenes (85.35%). The Brevundimonas diminuta was the least similar organism having a percentage similarity of 81.71% with the Geobacillus stearothermophilus. Bacterial spores are used as biological indicators for sterilization because they exhibit resistance to chemical and physical sterilization techniques. The protein common in all bacteria under study is Spo0A that make the bacteria heat resistant. The eradication of all these kind of heat resistant spores needs a high temperature which will also kill other viable cells. Keywords: Bacillus stearothermophilus; Bacillus pumilus; Bacillus atrophaeus; Clostridium sporogenes and Brevundimonas diminuta; Spo0A protein.