That Stinky Cheese Is a Result of Evolutionary Overdrive

Carl Zimmer in the New York Times:

ScreenHunter_1392 Sep. 27 20.10Like many biologists, Ricardo C. Rodríguez de la Vega searches the world for new species. But while other scientists venture into the depths of the ocean or the heart of the jungle, Dr. Rodríguez de la Vega and his colleagues visit cheese shops.

“Every time we’re traveling internationally for a conference or something, we go specifically to the local cheese shop and say, ‘Give me the wildest blue cheese you have,’ ” said Dr. Rodríguez de la Vega, an evolutionary biologist at the French National Centre for Scientific Research in Paris.

The cheese they buy is alive with fungi; indeed, many cheeses require a particular species of mold to properly ripen. To produce Roquefort blue cheese, for example, cheese makers mix Penicillim roqueforti into fermenting curds. The mold spreads throughout the cheese, giving it not only a distinctive blue color but also its (acquired) taste.

To produce soft cheeses such as Camembert or Brie, on the other hand, cheese makers spray a different mold species, Penicillium camemberti, on the curds. The fungus spreads its tendrils over the developing cheese, eventually forming the rind. When you chew on a Camembert rind, you’re eating a solid mat of mold.

In addition to influencing the taste, mold keeps cheese from spoiling by defending it from contaminating strains of fungi or bacteria.

By comparing the genomes of different species of molds, Dr. Rodríguez de la Vega and his colleagues have reconstructed their history. On Thursday in the journal Current Biology, the scientists reported that cheese makers unwittingly have thrown their molds into evolutionary overdrive.

More here.