L. lactis Bacteriophages and Methods of Their Elimination from Dairy Products

Dairy products are important in human diet and nutrition. That is why dairy production is critical not only economically, but also socially and medically. In recent decades, dairy production has had problems with disturbances in fermentation processes caused by bacteriophage contamination. It is important to note that every year there are new reports about newly discovered bacteriophages that disrupt fermentation processes in the production of kefir, yogurt, and various types of cheese. Lactococcus lactis strains are of particular importance in dairy technology, as they are used for the production of various yogurts and cheeses. The study of the spectrum of bacteriophages infecting this strain can help to monitor the evolutionary changes of viruses and the horizontal transfer of genes. In this paper, an analysis of phages infecting L. lactis was carried out. Most bacteriophages belong to the Siphoviridae and Podoviridae families. Moreover, the authors analyzed approaches that can be used to reduce bacteriophage contamination in the production of dairy products. It has been shown that the use of disinfectants, such as ethanol on sodium hypochlorite, can reduce the titer of bacteriophages and protect products from the development of viral infection. It is also possible to use membrane filtration with UV irradiation. Moreover, all these approaches can be combined to achieve the most effective result.