I used MHA media as a medium for testing the inhibitory power of the extract against bacteria, but the research that became my reference used Nutrient agar media for the test media. and the results of our study are very different, so whether the media used can affect the results of the inhibition zone formed?

Medium composition has a significant impact on the effects of antimicrobial compounds on bacteria. One of the most common effects is presence of salt, as they are assumed to alter uptake of certain antibiotics. Moreover, nutritional differences can affect how bacteria react/survive stressors including antimicrobial compounds.

I.e. measurements of MIC or inhibition zones are highly dependent on the media being used and cannot be easily transferred.