489: Soil Smell Synthesis Significance

01/29/24 • 8 min

This episode: Many organisms produce the smell of earth, geosmin, and many others can sense it–but why?

Download Episode (6.0 MB, 8.7 minutes) Show notes: Microbe of the episode: Acidianus spindle-shaped virus 1

News item Takeaways The smell of soil or earth is one of the most recognizable smells, and comes largely from a chemical called geosmin, produced by many different kinds of bacteria. Many animal species are sensitive to geosmin, some attracted by it and others repelled. But it is still not entirely understood what is the evolutionary benefit to the microbes that produce it, or the reason why different animals are sensitive to it in different ways. In this study, different geosmin-producing bacteria were paired with tiny bacteria-eating roundworms, nematodes, to see how the chemical affected their interactions. Production of geosmin affected the worms' movement, apparently inducing them to avoid colonies of the producing microbes in some cases, though the worms still sometimes fed on the bacteria. Adding geosmin to colonies of different bacteria did not affect the worms' behavior though, so other factors seem to be involved.

Journal Paper: Zaroubi L, Ozugergin I, Mastronardi K, Imfeld A, Law C, Gélinas Y, Piekny A, Findlay BL. 2022. The Ubiquitous Soil Terpene Geosmin Acts as a Warning Chemical. Appl Environ Microbiol 88:e00093-22.

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This episode: Many organisms produce the smell of earth, geosmin, and many others can sense it–but why?

Download Episode (6.0 MB, 8.7 minutes) Show notes: Microbe of the episode: Acidianus spindle-shaped virus 1

Email questions or comments to bacteriofiles at gmail dot com. Thanks for listening!

Subscribe: Apple Podcasts, Google Podcasts, Android, or RSS. Support the show at Patreon, or check out the show at Twitter or Facebook.

Previous Episode

488: Social Slimes Synchronize Sorties

This episode: Slime mold amoebas Fonticula alba have interesting and unique foraging and reproductive behaviors!

Download Episode (7.3 MB, 10.6 minutes) Show notes: Microbe of the episode: Cajanus cajan Panzee virus

News item Takeaways How did life develop from single-celled organisms acting independently into the complex, multicellular organisms we see and are today? Although it is difficult to look back through time to study how ancient organisms may have developed along this path, it is possible to investigate modern organisms that occupy a zone in between single-celled and multicellular, to see if we can get some hints to our own development, and also learn about some interesting microbes along the way! This study into the social amoeba, or slime mold, Fonticula alba, finds that the individual amoebal cells in a population join together into collectives and break apart into individuals at different stages of their complex life cycle, depending on the status of the bacteria around them that they forage as prey. The investigators tease out the various pathways taken by these amoebas.

Journal Paper:

Toret C, Picco A, Boiero-Sanders M, Michelot A, Kaksonen M. 2022. The cellular slime mold Fonticula alba forms a dynamic, multicellular collective while feeding on bacteria. Curr Biol 32:1961-1973.e4.

Email questions or comments to bacteriofiles at gmail dot com. Thanks for listening!

Subscribe: Apple Podcasts, Google Podcasts, Android, or RSS. Support the show at Patreon, or check out the show at Twitter or Facebook.

Next Episode

490: Parasitoid Pox Partners

This episode: A virus partners with a parasitoid wasp to help exploit fruit fly victims!

Download Episode (7.7 MB, 11.2 minutes) Show notes: Microbe of the episode: Actinomadura livida

Takeaways Parasitoid wasps have an interesting lifestyle: they inject their eggs into the larvae of other insects, and their young hatch and grow up by consuming the host from the inside. Some of these wasps also inject a virus along with the egg, which supports the wasp offspring by suppressing the host immune system. Most of these parasitoid helper viruses are integrated into the host wasp genome and are translated and produced as needed, but in this study, an independently replicating entomopoxvirus serves as an example of a virus-wasp mutualism. The study explores how the virus can infect the wasp prey, and how it gets passed on to wasp offspring.

Journal Paper: Coffman KA, Hankinson QM, Burke GR. 2022. A viral mutualist employs posthatch transmission for vertical and horizontal spread among parasitoid wasps. Proc Natl Acad Sci 119:e2120048119.

Email questions or comments to bacteriofiles at gmail dot com. Thanks for listening!

Subscribe: Apple Podcasts, Google Podcasts, Android, or RSS. Support the show at Patreon, or check out the show at Twitter or Facebook.