3. Identify the organism growing on the BOTTOM half of the agar and describe the observed hemolytic properties

flagellated bacteria such as E. coli

Explanation:

Briefly, in soft agar media, flagellated bacteria such as E. coli swim within the water‐filled tunnels in the agar matrix. The expanding colony typically extends from the bottom of the plate to the top surface of the plate with the majority of the cells embedded in the agar rather than at the air interface.

Properties

Some properties of the cell-free and cell-associated hemolysins of Escherichia coli were studied. Several strains of E. coli that were isolated from intestines of pigs with edema disease produce large quantities of cell-free hemolysin when grown in the presence of an extract of meat. The component of meat that stimulates production of cell-free hemolysin is not extracted by lipid solvents and is not dialyzable. The cell-free hemolysin is an acidic substance that occurs in two forms. It is inactivated by trypsin but not by lecithinase, lysozyme, ribonuclease, or deoxyribonuclease, shows optimum activity between pH 7 and 8, and requires calcium ion for activity. It does not appear to be an enzyme

b.

the accuracy of the data.