Food / Water / Environmental

  • A medium for the enumeration of coliform organisms in food and dairy products. Lactose fermenters produce red/purple colonies often surrounded by a halo of the same colour. Non-lactose fermenters produce pale colonies. Selective agents are Bile salts and crystal violet used to inhibit Gram positive and non-enteric organisms.
  • A modification of Violet Red Bile agar designed to give a ‘coliform’ count. In this medium lactose is substituted with glucose. Glucose is fermented by all members of the Enterobacteriaceae thus V.R.B.G.A gives a presumptive Enterobacteriaceae count. Bile salts and crystal violet are used to inhibit Gram positive and non-enteric organisms. The growth of non-fermentative Gram negative bacteria can be suppressed by using the agar overlay method.
  • Originally intended for use in surface counting and pour plating techniques in food and dairy products this medium can be used as a general-purpose medium for the cultivation of most non-fastidious organisms.