An Investigation of Quorum Sensing and Nutritional Triggers of Extracellular Enzymes by Psychrotrophs of Milk Origin

Psychrotrophs in raw milk elaborate heat-stable extracellular enzymes which survive pasteurisation causing a repertoire of spoilage defects. Previous work has provided circumstantial evidence that synthesis can be triggered as a reaction to extracellular chemical signal molecules i.e. quorum sensing agents. This project is directed at determining the extent to which extracellular enzyme synthesis is induced, if at all, by quorum sensing agents or whether it is induced by more simple nutritional stimuli.

<UL> <LI> Determine the role , if any of the quorum sensing phenomenon plays in inducing extracellular enzyme production by psychrotrophs.
<LI> Determine the contribution made by nutritional stimuli to extracellular enzyme induction in psychrotrophs.
<LI> Attempt to devise strategies compatable with the perceived naturalness of milk to inhibit extracellular enzyme production.
<LI> Determine the impact of such strategies on the safety of raw milk.