On the label to your Sainsbury's hard cheese is the word Lysozyme.

Lysozyme is an enzyme.

It's used in the food industry as a preservative. I found this description from Foodditive helpful:

Lysozyme acts as a natural preservative that inhibits the growth of bacteria that lead to spoilage. It is mainly used in the cheese industry in the maturation of European cheeses, by preventing the growth of Clostridium tyrobutyricum spores which cause butyric acid fermentation leading to product loss and spoilage.

In my wandering about looking for enzymes, I also found this youtube video useful. What else can you find about enzymes or lysozyme?