Jul 31, 2020 07:00:00

Researchers have identified the enzyme that causes 'wakiga', which may lead to the development of deodorant that suppresses the smell of wakiga

The pungent odor emitted from the armpit is also called wakiga, and some people may be struggling to care for their body odor. On July 27, 2020, a joint research team of the

University of York and Unilever announced in a paper published in Scientific Reports in an academic journal that 'the enzyme responsible for armpits has been identified'. The identification of the enzyme responsible for armpits may lead to the development of deodorants that effectively prevent the smell of armpits.

The molecular basis of thioalcohol production in human body odour | Scientific Reports
https://www.nature.com/articles/s41598-020-68860-z

Life in the pits: scientists identify the key enzyme behind BO-News and events, The University of York
https://www.york.ac.uk/news-and-events/news/2020/research/enzyme-body-odour/

Know sweat: scientists solve mystery behind body odour | Science | The Guardian
https://www.theguardian.com/science/2020/jul/27/know-sweat-scientists-solve-mystery-behind-body-odour

There are two types of sweat glands in the human body, one of which is the eccrine gland , which is distributed almost all over the body surface, and the other is the apocrine gland, which is distributed around the armpit, nipple, and genital area. It is said that the apocrine gland is the cause of wakiga because the sweat secreted by the apocrine gland has a higher concentration of components than the sweat secreted by the eccrine gland.

However, the human body itself does not directly produce thiol compounds, which are the most pungent odorants of wakiga, and the problem is the microorganisms present on the surface of the human body. The research team pointed out that the microorganisms that live in the skin eat a compound contained in sweat secreted from the apocrine gland to produce a substance that causes armpits as a by-product.

In a previous study, the team found that most skin-dwelling microbes do not produce thiol compounds. At this time, the cause of wakiga was a type of staphylococcus called Staphylococcus hominis that lives mainly under the armpit, and this microorganism is an odorless 'Cys-Gly-3M3SH' contained in sweat secreted from the apocrine gland. It was also found that when the compound was decomposed, a bad smell of wakiga was generated.

In this study, we further investigated in detail the mechanism by which Staphylococcus hominis produce an offensive odor, and investigated how thiol compounds are made from Cys-Gly-3M3SH. As a result, the research team found that the enzyme possessed by Staphylococcus hominis converts Cys-Gly-3M3SH secreted from the apocrine gland into a thiol compound.

The research team who discovered the enzyme that causes armpits is also conducting an experiment to add Cys-Gly-3M3SH to a gene that secretes this enzyme to a type of staphylococcus that does not normally affect body odor. As a result, the research team says that staphylococci, which should not release the causative agent of wakiga, now emits a malodor like wakiga.

'The thiol compounds are very important for body odor, because our nose excels at detecting very low concentrations of thiol compounds,' says Gavin Thomas , a microbiologist at York University. It has a very characteristic scent, like onions and onions, which is incredibly stimulating.'

The team also examined the genetic relationships between dozens of staphylococci and found that Staphylococcus hominis inherited the causative enzyme of wakiga from its ancestors some 60 million years ago. This result suggests that the causative enzyme of wakiga has existed long before the birth of humans and may have played an important role in social communication in primate ancestors.

'What we can say is that wakiga is not a new process. Wakiga definitely existed in the process of human evolution,' said Thomas. This research is also an important discovery for Unilever's research and development, and it seems that it may lead to the development of a new deodorant that selectively eliminates Staphylococcus hominis without affecting most microorganisms that live under the armpit.