GEOSMIN

Description

Geosmin and other volatile compounds are produced by a variety of bacteria, cyanobacteria, algae, and fungi. They are responsible for some of the odors of water supplies and food sources. Odor production is greatest when nutrient production and dissolved oxygen are high.

Description

Geosmin is a natural bicyclic terpene with an earthy odor. According to The Merck Index, it is the “major volatile component of beet essence, also . . . the potent earthy odor contaminant of fish, beans, [and] water.” The human nose can detect it at concentrations in air as low as 5 ppt.
In 1936, A. C. Thaysen at the Chemical Research Laboratory, Teddington (London) described an odorous compound produced by actinobacteria in fishing streams. About 30 years later, Nancy N. Gerber and Hubert A. Lechevalier at Rutgers University (New Brunswick, NJ) isolated it from several Streptomyces spp. They did not determine its structure but named it geosmin from the Greek words for “earth” and “smell”. Biochemist Gerber later elucidated its structure.
Flash forward to 2019, when biologist Marcus C. Stensmyr and postdoc Nadia Melo at Lund University (Sweden) observed that yellowfever mosquitoes (Aedes aegypti) are attracted to geosmin. Their colleagues at Florida International University (University Park) showed that A. aegypti like the odor so much that they lay their eggs in geosmin baits.
Beet peels are rich in geosmin, so Stensmyr engaged a team at the Federal University of Alagoas (Maceió, Brazil) to construct and test a simple trap baited with beet-peel extract. This is a win–win situation because the peel is a waste product. Stensmyr’s next steps are to optimize the trap and observe whether it significantly decreases mosquito populations.

The Uses of GEOSMIN

Geosmin is an earthly odorant resposible for the strong scent (petrichor) that occurs in the air when rain falls after a dry spell of weather or when soil is disturbed.

The Uses of GEOSMIN

Geosmin is an earthly odorant responsible for the strong scent (petrichor) that occurs in the air when rain falls after a dry spell of weather or when soil is disturbed.

Definition

ChEBI: (-)-geosmin is the (-)-stereoisomer of geosmin, having 4S,4aS,8aR configuration. It is an enantiomer of a (+)-geosmin.