Context
Bacteriophages or phages are viruses that can infect bacteria. These viruses are present in ecosystems where bacteria can be found. A wide range of food products needs the use of large-scale fermentation process. Manufacture of products such as cheese, sour cream and buttermilk requires the use of lactic acid bacteria at large concentrations, Lacto-coccus lactis being one of the most important used species.
Lactococcal cultures are susceptible to be infected by lactococcal lytic phages. Mainly three species of these phages are encountered in dairy plants, SK1 (formerly 936-type), C2, and P335. These phages species possess a high tolerance to sanitation treatments and display an aggressive infective nature; they are often responsible of fermentation process issues as low, delayed or incomplete process and variations in taste and texture of products.
In order to avoid lactococcal infection, it is important to determine the phage concentration in the environment and implement measures to control their levels. The use of ozone as a decontaminating agent has been introduced to the market. Ozone is an unstable gas. Its penetrability, high reactivity and natural decomposition make ozone the ideal disinfectant to ensure the microbiological safety of elements and equipment, without leaving chemical residues. Ozone is 52% stronger than chlorine, and it has been proven to be more effective on a much larger set of microorganisms than all other disinfectants. In the present study, we report the impact of ozone treatment on the bacteriophages present in the air in a dairy factory.
