Bacteria To Consider For The Growth Promotion Test: Should Anaerobic Cultures Be Included?

The Growth Promotion Test (GPT) is conducted to evaluate whether the culture media is suitable for use in environmental monitoring sampling. By introducing a small number of microorganisms, the test ensures that the medium’s nutritive properties, functionality, and overall quality are sufficient for detecting and counting microbial contaminants.

Both solid media and broths can be tested for GPT in accordance with the European and United States Pharmacopoeias. The test involves inoculating the media with ≤ 100 CFU of microorganisms specified by the pharmacopeia. In quantitative tests, 50–200% of the inoculated microorganisms should be recovered after incubation, while qualitative tests simply assess whether growth occurs. It is crucial to perform GPT for each new batch of medium, with checks conducted on both agar media and nutritive broth, though not on diluted broth. Keep reading to explore recommendations to follow to ensure a successful GPT.