Mutational inactivation of proteins involved in para-cresol production in
certain milk products results in improved taste and odor. The undesirable
para-cresol forms over time as a result of enzymes produced by the
bacterium that produces gellan gum. Since the gellan is typically used in
a relatively unpurified form, the enzymes are added to the milk along
with the gellan. Inactivation of the enzymes is a genetic means of
eliminating the enzymes without requiring any additional purification or
processing.