Selective King’s B Medium for Gram Negative Bacteria v1

King’s B (KB) medium is a nutrient-rich selective medium primarily used for the isolation and growth offluorescentPseudomonasspecies, particularlyGram-negative bacterium. This protocol describes the preparation of KB medium, including the addition of antibiotics tosuppress unwanted microbial growth.Cycloheximide (100 mg/mL)is incorporated toinhibit fungal contamination, whilecephalexin (10 mg/mL)is used toretard the growth of Gram-positive bacteria, ensuring selective enrichment of Gram-negative bacteria such asPseudomonas. The procedure involves media preparation, sterilization, antibiotic addition, and plate pouring under sterile conditions. The expected outcome is aselective growth mediumthat promotes the recovery and study ofPseudomonasspecies, particularly those producingfluorescent pigments, which can be visually detected under UV light.