Friday, December 27, 2013

My New Favorite People Make Cheese Out of Human Body Odor-Producing Bacteria

If there are three things I love in this world, it is cheese, science, and unprofitable-but-fascinating projects. Microbiologist Christina Agapakis and artist Sissel Tolaas decided to mush my interests together in a project called Selfmade. The pair created individual "portraits" of participants (the likes of whom included food writer Michael Pollan and installation artist Olafur Eliasson) by swabbing them and making cheese from their body's bacteria.

Formerly Michael Pollan's Bellybutton
Source: http://agapakis.com/selfmade.html
Generally, the first step in cheese production involves curdling the milk, separating it into solid curds and liquid whey. Bacteria from the Lactococcus genus, the Lactobacillus genus, and the Streptococcus genus are the most common starter bacteria for this process. These bacteria convert the sugars in the milk into lactic acid. When casein micelles, the bundled up globs of protein suspended in your milk, hit acid, the positive hydrogen atoms in the acid neutralize the negative casein proteins. Then, since nothing is repelling them from each other, they clump together, forming curds. Rennet, an enzyme complex produced by mammalian stomachs, is also usually used to help curdle the future-cheese. (Swiss cheese and other hole-filled cheeses also get an extra dose of Propionibacterium freudenreichii, which produces buttloads of carbon dioxide, giving Swiss its distinctive hole-y-ness.) For some cheeses (e.g. a fresh, soft goat cheese), that's all the needs to happen. Boom. Packaging time. Most, though, require further processing. Harder cheeses are heated to force out more of the soggy whey. Cheeses like mozzarella are stretched in hot water to help develop their melty, stringy quality. Cheddar goes through a process called, creatively enough, cheddaring. Lower-acid cheeses, like Gouda, are washed. Additionally, salt is added... because it is delicious. Many (most) cheeses are then ripened, turning from bland to complex as the casein proteins break down into amino acids, fatty acids, and amines. For some cheese, additional bacteria and molds will be added at this stage. For example, Brevibacterium linens, found on cheeses like Munster and Limburger, adds a uniquely orange hue. Blue cheeses are formed from exposure to fungi like Penicillium roqueforti or Penicillium glaucum. 

Many of these microorganisms are ubiquitous on human skin. If you're not a biology nerd, but some of these genus and species names sound familiar, you might be remembering them from my deodorant post in September, where I talked about what bacteria are responsible for your stinkiness. (You can find it by clicking here.)

Lactococcus has been isolated on human skin in small quantities and there is evidence that it may serve an antimicrobial (well, anti-other-microbial) function. You're pretty much coated in Lactobacillus-- you can find it hanging out not only in small quantities on your skin, but in your gastrointestinal tract, in your tooth decay, and inside your vagina. (You can also thank Lactobacillus for yogurt and pickles.) Streptococcus is similarly abundant on your body. In addition to your skin, it can be found in your mouth, intestines, and respiratory system. Brevibacterium linens is one of the bacteria responsible for foot odor.

As cheese microbiologist Benjamin Wolfe says, "There's been really great recent work on the microbiome of people's feet, looking at both the bacteria and the fungi... and if you look at that data and you put our cheese data right next to it, they look pretty much the same."

In total, Agapakis and Tolaas made 11 cheeses, taking swabs from everything from mouths to belly buttons to feet. This formed the bacterial basis for their cheeses. Agapakis told NPR, "The idea was to recognize, how do we get grossed out? Then to think about it and move beyond that initial idea of disgust. Why are we more uncomfortable with bacteria on the body than we are with bacteria in cheese?"

Interviews suggest that no one has actually tasted the cheese, which is a disappointment. But, like... you first. 

The project is currently on display at the Science Gallery in Dublin.

Aching for more information? Check out Christina Agapakis's website here and here...

...this short video:


...or this Science Gallery promotional video:

13 comments:

  1. I'm not sure if this is amazing or disgusting or amazingly disgusting, but I am currently really glad I'm allergic to dairy.

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    1. Luckily, those of us without dairy allergies aren't being tied to chairs and forced to eat it, either.

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  2. Ok, this is weird and awesome, I love it! I am a cheese maniac.

    http://mattekat.blogspot.ca/

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    1. Me too! Yesterday I just had cheese and bread for dinner. That is what happens when the boyfriend is out of town.

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  3. I've always found cheese sort of gross so this doesn't seem any worse than regular cheese to me. Yet somehow I still want people to eat it and tell me what it tastes like. For.. uh... science?

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    1. I totally volunteer someone else to eat it for science.

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  4. This is...awesome. And I would totally volunteer to eat some, because...for science.

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    1. I would eat it if it was made from me.

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  5. This is many kinds of awesome. I think, really, that this sort of thing is the most fun you can have, as a scientist.

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  6. I'm not gonna lie, I kinda want to taste this cheese. I mean. . . I would lick most people, and it's not all that different, right?

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