<Li> Lactose non-fermenters may increase the pH by deamination of proteins . This ensures that the dye is not absorbed . The colonies will be colorless . </Li> <P> On EMB if E. coli is grown it will give a distinctive metallic green sheen (due to the metachromatic properties of the dyes, E. coli movement using flagella, and strong acid end - products of fermentation). Some species of Citrobacter and Enterobacter will also react this way to EMB . This medium has been specifically designed to discourage the growth of gram positive bacteria . </P> <P> EMB contains the following ingredients: peptone, lactose, dipotassium phosphate, eosin Y (dye), methylene blue (dye), and agar . </P> <P> There are also EMB agars that do not contain lactose . </P>

Emb is a selective medium. is it also