Dairy bacteriophages and phage resistance

Abstract

Lactic acid bacteria (LAB) have been the focus of substantial research due to their economic importance in food fermentation. Bacteriophage infection leads to the lysis of starter cells, thereby interrupting the fermentation. The consequence of a phage infection is therefore a fermentation delay, an alteration of the product quality and, in severe cases, the loss of the product, with the associated economic losses. This chapter describes the general characteristics (morphology, composition, life style) and classification of principal dairy phages, as well as the main measures and biotechnological defence strategies developed to measures to alleviate this problem has been adopted over the years but has invariably resulted in a very limited number of strains which can withstand intensive usage in industry. The application of genetic techniques to improve the phage-resistance of starter cultures for dairy fermentations has been intensively studied for the last twenty years to a point where this approach now has significant potential to alleviate the problem. This chapter highlights the recent findings and developments that have been described in the literature that will have an impact on improvement of the phage-resistance of starter cultures. measures to alleviate this problem has been adopted over the years but has invariably resulted in a very limited number of strains which can withstand intensive usage in industry. The application of genetic techniques to improve the phage-resistance of starter cultures for dairy fermentations has been intensively studied for the last twenty years to a point where this approach now has significant potential to alleviate the problem. This chapter highlights the recent findings and developments that have been described in the literature that will have an impact on improvement of the phage-resistance of starter cultures.