GC-MS

You should be read about GC-MS to identify all of the compounds that got from the extract.

Kindly check the following reference that may be useful

-Alabi, O. S., Koleoso, O. B., & Abiala, A. M. (2019). Antimicrobial screening and GC-MS analysis of bioactive compounds from strains of Pseudomonas aeruginosa isolated from poultry fecal littered soil in Ibadan, Nigeria. Nig J Pure & Appl Sci, 32(1), 3347-3357.

Best regards

Saleh Al maaqar@@@‏

Dear Lazar Gardijan:

Pkease check this similar question:

https://www.researchgate.net/post/Why_does_the_supernatant_from_Bacillus_sp_doesnt_represent_any_antibacterial_activity

You can look for scientific papers where bioactive metabolites are extracted from the inhibition halo that you see on the agar plate.

Do you already have information about the identity of your isolate?

In recent years, there has been a growing interest in researching and developing new antimicrobial agents from various sources to combat microbial resistance. Therefore, a greater attention has been paid to antimicrobial activity screening and evaluating methods. Several bioassays such as disk-diffusion, well diffusion and broth or agar dilution are well known and commonly used, but others such as flow cytofluorometric and bioluminescent methods are not widely used because they require specified equipment and further evaluation for reproducibility and standardization, even if they can provide rapid results of the antimicrobial agent's effects and a better understanding of their impact on the viability and cell damage inflicted to the tested microorganism. In this review article, an exhaustive list of in vitro antimicrobial susceptibility testing methods and detailed information on their advantages and limitations are reported.