M-Green Select Broth

M-Green Select Broth is an improved modification of the
liquid medium M-Yeast and Mold Broth. It was developed to improve efficiency of detection and
enumeration of fungi in sugar based drinks using the membrane filtration method. This medium has a
low pH, which inhibits bacterial growth. Bromocresol green indicates pH change: yellow (acid
reaction), green (alkaline reaction). When bromocresol green diffuses into fungal colonies it has an
alkaline reaction, allowing identification easily. Metabolic by-products from the developing colonies
diffuse into the surrounding medium, further reducing the pH which aids in the inhibition of bacterial
growth, but also produces an acid reaction which causes residual bromocresol green to change to
yellow. The addition of chloramphenicol further inhibits the growth of bacteria to allow for the
development and enumeration of yeast and mold.