Starter cultures phages

EPSs produced by starter cultures in fermented dairy products represent a complex matrix of polymers that provide a protective function to the fermenting strains against phages and toxins. After ingestion, these EPSs will ultimately come into contact with the host intestinal microbial population the question is therefore raised is there a relationship that emerges between this EPS and the microbiome ... 

Instances of bacteriophage-induced stuck MLF appear to be random in occurrence. This may result from the relatively low bacterial population density (10 -10 CFU/mL) compared with starter cultures at 10 CFU/mL. Because phage infection requires identification of unique receptor site(s) on the bacterial cell wall, the use of alternate or multiple-strain LAB cultures may preclude or mitigate stuck MLF (Cone, 1995 personal communication). 

Control phage proliferation includes, among others, direct inoculation of milk with concentrated starter cultures use of antiphage starter medium use of separate rooms for starter production and cheese manufacture regular cleaning and disinfections (chlorinate) of vats, equipments, rooms (laboratory and factory), clothes, and air (positive filttation) rotation of starter strains. 

Starter cultures are continuously exposed to phage attack in food fermentations. Dairy fermentations are particularly susceptible to phage attack due to the rather limited starter culture repertoire and the use of non-sterile substrates such as milk. Moreover, in many dairy plants starter cultures are cultivated in large volumes and in rich media, which are ideal conditions for phage propagation. Therefore, strategies to avoid the presence and survival of phages in dairy factories have always been a matter of concern. 

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