In this study, stab agar is used to determine the motility and the growth pattern of the Klebsiella and E.coli. Deep stab is a test tube filled with a solid containing agar and is inoculated with a stab wire. Both bacteria used produce a stab line (filiform) in the stab agar. The agar remains clear as Klebsiella and E.coli are non-motile bacteria. These bacteria are facultative anaerobes which mean that they can grow either in the presence of oxygen or absence because both grow deep to the bottom of the stab agar. MacConkey agar is used in this experiment to show the ability of gram-negative bacteria to metabolize lactose. Colony of a gram-negative bacterium will form pink colour when the lactose is metabolized and acid is being produced.
