The disk diffusion test, also known as the Kirby-Bauer test, is a standard method used to evaluate the effectiveness of antimicrobial substances against bacteria. In this method, small disks infused with an antimicrobial agent are placed on an agar plate inoculated with a bacterial culture. As the agent diffuses from the disk, it inhibits bacterial growth in a clear area around the disk known as the zone of inhibition. The size of this zone helps determine the effectiveness of the agent.
Escherichia coli (E. coli): A common gram-negative bacterium found in the intestines of warm-blooded organisms. It is often used in laboratory studies and can be both harmless and pathogenic.
Transformed E. coli with GFP and Amp Resistance: This strain of E. coli was genetically modified to express green fluorescent protein (GFP) and carry a gene providing resistance to the antibiotic ampicillin, enabling it to glow under UV light and survive in the presence of the antibiotic.
Pseudomonas fluorescens: A gram-negative bacterium known for its ability to produce a fluorescent pigment (pyoverdin, a greenish and water soluble pigment). It is often found in soil and water and can act as a plant growth-promoting bacterium. Although it typically isn't infectious, it can cause nasty infections like pneumonia and bacteremia.
Mixed Culture of Probiotic Bacteria: This culture included Lactobacillus acidophilus (balance the intestinal microbiome by boosting the growth of benifitial bacteria), Bifidobacterium bifidum (aids in digestion, boost the immune system, and potentially mitigate conditions like IBS), and Lacticaseibacillus casei (helps regulate the digestive system, potentially aiding in the prevention or treatment of various digestive issues. L. casei may contribute to overall health by reducing inflammation and potentially improving mood.). These are beneficial bacteria commonly found in the human gut and used in probiotic supplements for promoting digestive health.
Cuttlefish Ink: Traditionally used in cuisine, cuttlefish ink also possesses antimicrobial and antioxidant properties. It contains melanin and peptides that may inhibit the growth of certain bacterial strains, making it of interest for biomedical applications.
Agave: Known for its use in producing tequila and sweeteners, agave also contains saponins and flavonoids with antibacterial and anti-inflammatory effects. It has been explored in traditional medicine and modern studies for its potential antimicrobial applications.
Brown, j. kirk. (1/1/2011). Biotechnology a Laboratory skills Course (2nd edition). Bio-Rad Laboratories. Disk Diffusion Lab.pdf.
Shegute T, Wasihun Y. https://pmc.ncbi.nlm.nih.gov/articles/PMC7648529/
Abdel-Malek AR, Moustafa AY, Salem SH. https://bmcbiotechnol.biomedcentral.com/articles/10.1186/s12896-024-00880-3