Ecology of Dairy Bacteriophages

Project entitled:

Controlling Bacteriophages from Farm to Plant

Summary

The increase in cheese production and the repeated use of the same lactic ferments increases the risk of fermentation failure due to the presence of phages in milk. Several strategies are now available to mitigate phage-related problems. Nonetheless, phages are still the main cause of delays in dairy fermentation and fluctuation in the quality of certain cheeses. Over the years, the phage problem has often been passed on to lactic ferment providers. Indeed, a manufacturer must distribute ferments that are insensitive to most phages and monitor phage populations. However, it is also important for processing plants to use proper control strategies in parallel, including an effective cleaning procedure. Ideally, the sources of contamination should also be known so they can be controlled optimally. This project aimed to identify phage sources in plants and in farms, study airborne phage behaviour and assess the effectiveness of physical and chemical methods to control phages.