We live in biological world completely surrounded by rich communities of microorganisms, but often in a cultural world that emphasizes total antisepsis. But “sanitized and pasteurised for your protection” is the antiseptic symbol of sensory death. Because not all smells and bacteria can be pleasant, the consequences of hyper-sanitation could be that we decide to have none at all. Smells, bacteria, and bacteria that produce smells surround us all the time; chemical detection is an ancient biological communication tool used by bacteria and animals alike. Smells and bacteria are a crucial component in defining, understanding of and orienting in any environment.
The intersection of our interests in smell and microbial communities led us to focus on cheese as a “model organism.” Many of the stinkiest cheeses are hosts to species of bacteria closely related to the bacteria responsible for the characteristic smells of human armpits or feet. Can knowledge and tolerance of bacterial cultures in our food improve tolerance of the bacteria on our bodies or in other parts of our life? How do human cultures cultivate and value bacterial cultures on cheeses and fermented foods? How will
synthetic biology change with a better understanding of how species of bacteria work together in nature as opposed to the pure cultures of the lab?
Will we be able to re-engineer bacterial communities as readily as we can add or delete genes to and from E. coli? How will synthetic biology change our relationship to the microbial communities that surround us?
We were fascinated by the similarities between cheese and human microbiodiversity and curious about the historic origin of cheese microflora. Given the physicality of cheesemaking, we speculated on the human origins of many of the unique cheese flavors. To explore this hypothesis and to foreground the microbiology of our food and bodies, we sought out to make cheeses with starter cultures isolated from the human body. Swabs from hands, feet, noses, and armpits were inoculated into fresh, pasteurized, organic whole milk and incubated overnight at 37° Celsius. The milk curds were then strained and pressed, yelding unique smelling fresh cheeses. Eight cheeses were produced in total for further study, with bacterial origins from the bodies of the Synthetic Aesthetics team.
Comparative smell-omics of the cheeses analyzed with headspace technology. The largest difference in odor and bacterial diversity was between Armpit-3 (pink) and Foot-5 (blue). Armpit-3 had the most pleasing, cheese-like smell, and also contains the largest number of ketones previously identified as being involved in cheese odor. For more information, read my thesis chapter on the Synthetic Aesthetics project (PDF).