Better-Smelling Beer attracts Fruit Flies

A new research has found that the smell of beer not only attracts beer lovers, but fruit flies as well. The research team discovered that fruit flies and yeast, a type of fungus that is used in making beer and wine, have evolved a mutually beneficial relationship that hinges on yeast's smell.

According to the research, volatile compounds produced by yeast give a very strong smell to beer that's like ripening fruit. Scientists had previously discovered the gene that is responsible for pleasant smell of beer. As per the discovery, if species like S. cerevisiae, yeast of brewer, would be knocked out of the gene, it would not release a pungent smell like ripening fruit. On the other side, if the gene is overactivated with S. cerevisiae, the yeast produce even more of the aroma.

Kevin Verstrepen, a bioengineer, said that while studying the gene years ago, he had noticed that fruit flies in his lab swarmed around over-activated yeast, and did not pay attention to non-fruity yeast.

In the new research, Verstrepen and other researchers from the University of Leuven and the Flanders Institute for Biotechnology in Belgium observed the reaction of fruit flies to mutant beer yeast. To know more, scientists sent some fruit flies into a cage and blew in air collected from different S. cerevisiae. According to researchers, the flies were attracted to smelliest yeast and didn't pay attention to the non-fruity yeast air.

Researchers said that while showing a strong preference for smelliest yeast, the fruit flies unwittingly picked up the microbes on their legs.

According to Verstrepen, both species of yeast gained attraction and it's a relationship likely to have been around for millions of years. Fruit flies consume S. cerevisiae for protein. In exchange, yeast use fruit flies to disperse to new habitats. Verstrepen said, "I think it's the first description of this kind of smell-based collaboration".