A transmission power of a communication apparatus can be appropriately determined in accordance with different communication multiplicities between two or more communication channels. P100 and the endolysin from P100 can be administered to food products, to the components that will be added to food products, andor to the infrastructure of the food processing plants within which such food products are processed, or the containers or wraps in which such foods are stored andor shipped, in order to reduce Listeria monocytogenes contamination. By using Bipolar Junction Transistor instead of Field Effect Transistor as the main switches and also a lower value electrolytic, the cost and size are considerably reduced.