A MODIFICATION OF THE PSEUDOMONAS SELECTIVE MEDIUM, CFC, THAT ALLOWS DIFFERENTIATION BETWEEN MEAT PSEUDOMONADS AND ENTEROBACTERIACEAE

Certain members of the family Enterobacteriaceae developing on beef st eaks packaged in modified atmospheres may grow on the medium CFC (Ceph aloridine-Fucidin-Cetrimide), which is selective for pseudomonads. The addition of arginine (1% w/v) and the pH indicator phenol red (0.002% w/v) to this medium differentiated between the two groups. The pseudo monads produced ammonia from arginine, whereas Enterobacteriaceae gene rally did not use this substrate. The alkaline drift in pH in and arou nd pseudomonad colonies gave a pink colouration with phenol red.