Fungi and bacteria play a big part in shaping the flavor and texture of cheese.
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Some cheeses are mild and soft like mozzarella, others are salty-hard like Parmesan. And some smell pungent like Époisses, a funky orange cheese from the Burgundy region in France.
There are cheeses with fuzzy rinds such as Camembert, and ones marbled with blue veins such as Cabrales, which ripens for months in mountain caves in northern Spain.
Yet almost all of the world’s thousand-odd kinds of cheese start the same, as a white, rubbery lump of curd.
How do we get from that uniform blandness to this cornucopia? The answer revolves around microbes. Cheese teems with bacteria, yeasts and molds. “More than 100 different microbial species can easily be found in a single cheese type,” says Baltasar Mayo, a senior researcher at the Dairy Research Institute of Asturias in Spain. In other words: Cheese isn’t just a snack, it’s an ecosystem. Every slice contains billions of microbes — and they are what makes cheeses distinctive and delicious.
People have made cheese since the late Stone Age, but only recently have scientists begun to study its microbial nature and learn about the deadly skirmishes, peaceful alliances and beneficial collaborations that happen between the organisms that call cheese home.
To find out what bacteria and fungi are present in cheese and where they come from, scientists sample cheeses from all over the world and extract the DNA they contain. By matching the DNA to genes in existing databases, they can identify which organisms are present in the cheese. “The way we do that is sort of like microbial CSI, you know, when they go out to a crime scene investigation, but in this case we are looking at what microbes are there,” Ben Wolfe, a microbial ecologist at Tufts University, likes to say.
Early on, that search…