Body odor is caused by the metabolic action of bacteria on human sweat. Existing deodorants are antibiotic - they kill all skin bacteria including neutral and beneficial species. Where body odor carries a social stigma, alternatives to deodorant are few.
The iGEM Paris Bettencourt 2014 project explores new ways to control body odors through precise modifications of the living microbiome. We target common odors of the armpit and foot, as well as odors specific to old age or genetic disease. We present a BioBrick smell library for mixing genetic perfumes and a CRISPR-mediated technology for isolating naturally odorless bacterial strains.
Our work represents a probiotic and body-positive approach to body odor that will someday help people to smell just like themselves.
Here we present a genetic odor palette. It is built of BioBricks to express enzymes to produce volatile compounds with characteristic smells. We included smells with different tonalities to allow exploration of the "odor space" resulting from combinations of smelly units.
Trimethylaminuria (TMAU) is a rare genetic disease causing a strong fish odor to appear in the sweat. Here we engineer skin bacteria to degrade trimethylamine, the odor causing molecule, with the enzyme TMM (trimethylamine monooxygenase).
Isovaleric acid, the cheesy component of foot odor, is produced by B. subtilis through the leucine degradation pathway. We characterize B. subtilis mutants in this pathway, in vitro and in situ (on socks).
Armpit odor comes mainly from aminoacylase enzymes expressed in the genus Corynebacteria. This project is developing CRISPR technology to isolate natural bacterial mutants that lack these enzymes.
2-nonenal is "old people smell," a component of sweat that increases with age. Here we isolate and characterize bacterial species that metabolize 2-nonenal and attenuate its characteristic odor.