A phage against yogurt processing

The phiY8 phage is the natural killer of Lactobacillus acidophilus Y8.
This Lactobacillus Y8 being an important actor in yogurt !
Kiliç & coll 1996 

A fuel killer

Butanol fuel can be produced using Echerichia coli bacteria.
Phages kill the Echerichia.
Peralta-Yahya & coll 2012 

A vinegar killer

Bacteriophage GC1 kills Gluconobacter Cerinus, an Acetic Acid Bacterium.
Philippe 2018

So all the bacteria based fermentation processes are in danger of failing because of the activity of phages against bacteria.