Without wasps, many of your ingredients might not exist at all. Irene Stefanini and Leonardo Dapporto from the University of Florence have found that the guts of wasps provide a safe winter refuge for yeast. They found several species of yeast in the wasps’ guts (but not the bees), including 17 strains of specifically Saccharomyces cerevisiae which is the fungus we use to make wine, beer and bread.
The duo writes in a PNAS Direct Submission “Wasps can maintain a potentially unending transmission of yeast strains.”
S.cerevisiase has been our companion for at least 9,000 years, not just as a tool of baking and brewing but as a leader of modern genetics. It has helped us to make remarkable scientific progress and drink ourselves silly, possibly at the same time. But despite its significance, we know very little about where the yeast came from, or how it lives in the wild.
It’s possible that other animals could act as hosts for S.cerevisiae, and Stefanini and Dapporto acknowledge as much. However, they think that the list of candidates is short. The yeast has been found in the genitals of birds although they only last there for half a day. It has been found in other insects, but these are usually too short-lived to sustain the fungus from year to year. Social wasps that plague our picnics are special in that they hibernate and provide a refuge and feed their young which provides a continuous source of fresh carriers.
