Molecular basis of human body odour formation: insights deduced from corynebacterial genome sequences

During the past few decades, there has been an increased interest in the essential role of commensal skin bacteria in human body odour formation. It is now generally accepted that skin bacteria cause body odour by biotransformation of sweat components secreted in the human axillae. Especially, aerobic corynebacteria have been shown to contribute strongly to axillary malodour, whereas other human skin residents seem to have little influence. Analysis of odoriferous sweat components has shown that the major odour-causing substances in human sweat include steroid derivatives, short volatile branched-chain fatty acids and sulphanylalkanols. In this mini-review, we describe the molecular basis of the four most extensively studied routes of human body odour formation, while focusing on the underlying enzymatic processes. Considering the previously reported role of β-oxidation in odour formation, we analysed the genetic repertoire of eight Corynebacterium species concerning fatty acid metabolism. We particularly focused on the metabolic abilities of the lipophilic axillary isolate Corynebacterium jeikeium K411.