Vinegar. It is a powerful antibacterial. It is a low pH acid. Most bacteria do not survive in that environment. Can be seen as an ingredient to its use in pickling. Even more potent when combined with salt.
Acid. Includes vinegar, citric acid, and others.
Salt. It absorbs the water in and on the food. Without water, bacteria cannot live or multiply. In high concentrations, it can also pull the salt right out of the cells of the bacteria and killing it.
Sugar. It absorbs water similar to salt. The concentration must be very high to be effective. Mostly can be seen in candies that have an extremely long shelf life.
Heat. It kills. Used to sterilize containers, kill bacteria in food in the containers, and pasteurization.
Freezing. Freezing temperatures either kill the bacteria or put them into "hibernation". Most foods will last forever in the freezer if it weren't for freezer burn.
Smoke. I have no idea how but smoke kills bacteria as well. Seen in smoked meats.
Dehydration. Removing almost all the water in the food will prevent bacteria from growing. Used in jerky and other cured meats.