Can viruses stabilize and increase the shelf life of wine and other foods?
There is at least one bacteriophage ("phage") that targets bacteria that spoil wine:


  The Gluconobacter phage GC1 is a novel member of the Tectiviridae family isolated from a juice sample collected during dry white wine making. The bacteriophage infects Gluconobacter cerinus, an acetic acid bacterium which represents a spoilage microorganism during wine making, mainly because it is able to produce ethyl alcohol and transform it into acetic acid.


This particular linked paper does not say anything about usage of bacteriophages as a food preservative or for food safety, but there is interest in using bacteriophages for this general application, as an alternative to the use of antibiotics in food production.

Phages are everywhere. Craig Venter went out on his yacht and scooped up a bunch for one of his papers. Phage therapy may end up augmenting or replacing antibiotics, which would be good for us humans as many disease-causing bacteria have developed or are developing resistance to them.