For well over a century, most of the world’s brie and camembert producers have been sourcing a key ingredient, the fungus Penecillium Camemberti, from the same strain, leaving the cheeses vulnerable to disease and other threats. This, according to French researchers who are sounding the alarm: either we “re-wild” the cheese or  risk losing it, at least in its creamy white current form. The World’s Gerry Hadden reports from Paris.