The person responsible for the pleasant smell of wet earth that we usually perceive after the rain is a harmless bacterium called Streptomyces coelicolor . This spore-producing microbe is found in most soils and produces a substance called geosmin , a word of Greek origin that means "aroma of the earth." Although this smell is perhaps nothing more than anecdotal and evocative for humans, for camels it can make the difference between life and death. And it is that scientists suspect that this molecule is detected by their olfactory receptors when these animals travel through the desert, indicating that there is water nearby. If confirmed, it would explain why camels in the Gobi desert are able to find water more than 80 kilometers away.
The Streptomyces coelicolor genome was sequenced in 2001 and its nearly 8,000 genes were published in the journal Nature .
