Mannitol Motility Test HiVeg™ Medium is a semisolid medium suitable for determining motility and mannitol fermentation for differentiating bacteria. Motile bacteria produce diffused growth throughout the medium while non-motile bacteria grow only along the line of inoculation. Mannitol on fermentation creates acidic conditions. Phenol red is the pH indicator. Colour of the medium changes from red to yellow. This medium is prepared by replacing animal peptones with vegetable defined peptones to avoid BSE/TSE/GMO risk.