Bacterial transport and catabolism of human malodour precursors

The characteristic smell of body odour (BO) is familiar to us all and is a biological process that is a known evolutionary trait in mammals, with strong associations to mate selection and sexual attraction. What is not widely known is that odours themselves are solely the product of metabolism of the underarm (axilla) microbiota. We have discovered a number of bacteria that live in the human axilla that are responsible for the production of two major BO components, thioalcohols and volatile fatty acids. In this project we will fully elucidate the molecular and biochemical basis for the production of these chemicals, both at the level of the transporters that taken the odourless axilla secretions up into the bacterial cells and the intracellular enzymes that liberate the malodourous molecules from this precursors. The project, a LINK grant application, will also provide important data for Unilever, a large UK based company, to progress their deodorants business

The production of the two main body odour (BO) components, thioalcohols and volatile fatty acids, by the axilla microbiota is poorly studied, but is an ancient commensalism in humans. We have discovered the key bacterial species that produce thioalcohols and have made preliminary identifications of both the transporter and one of the catabolic enzymes used by the staphylococcal bacteria to convert odourless thialcohol precursors secreted from the axilla into free thioalcohols. In this project we will study these reactions in detail and fully elucidate the pathway required for thioalcohol production, which our data suggests also involves an uncharacterised dipeptidase. This will be achieved using genetic and microbiological approaches, but also a rigorous biochemical approach to assess transporter and enzyme function and to test the hypothesis that the malodour producing bacteria have evolved specific enzymes that allow them to metabolise thioalcohol precursors. We will also study how the free thioalcohols leave the cell, which could be through an active efflux mechanism. We will then, through working closely with a research in Unilever, use this same approach to study for the first time how a newly identified species of Anaerococcus produce VFAs, the second main class of compound in BO.

The clear potential interest of the results that come from this work suggest a variety of routes and opportunities to create impact in both the commercialisation of the data and also the dissemination of the work to the general public.
The objectives for this project in terms of impact are:
1) To disseminate the results of the research to academic and industry stakeholders.
2) To capture the intellectual property of this project and continue to build a strong relationship with Unilever to exploit this work.
3) To provide an excellent environment for Daniel Bawdon to continue his scientific development via additional training & continued close working between industry & academia
4) To engage with the general public and other scientists on the topic of BO and its production by bacteria.

This will be achieved first through normal route of publication and presentation at research conferences, ensuring that the IP protection for any valuable work has been put in place first. We will work with our Enterprise office to continue our strong working relationship with Unilever into this project to ensure the maximal benefit for the University & the company. We have included in the project a number of opportunities for the PDRA to gain additional skills training, for example, he will obtain additional training in Staphylococcal genetics through a research visit to Dr. Malcolm Horsburgh's lab in Liverpool. There are also a wide range of transferable skills he can improve that are available through the University.
We will focus some effort on public engagement in this project, as the nature of the project, working on BO in humans, is particularly suited to this. Our proposed activities for this part of the impact plan are

i) Prepare an activity for local secondary school called "The science of smelly armpits" which focuses on BO and its biological formation and biological function. This will be aimed at students from KS2 onwards and delivered at 4 primary & secondary schools in York. The summer students working on this project will help prepare materials for this.
ii) Prepare a similar activity for the 2018 York Festival of Ideas for an adult audience.
iii) Work with the Society for General Microbiology (SGM) (GHT is a member of their Communications committee) to prepare a briefing document on the role of bacterial in BO production and write an article for the SchoolZone section of their society magazine, Microbiology Today.
iv) GHT will be lecturing to the Yorkshire Philosophical Society in late 2014 on biofuels, so will propose a lecture in 2018 on the "The science of smelly outpits".
v) We will update relevant pages on Wikipedia to bring knowledge of the bacteria role in BO production up to date.