Soil Gets Its Smell From Bacteria Trying To Attract Invertebrates (newscientist.com) 11
"Soil gets its characteristic earthy smell from certain chemicals produced primarily by soil-dwelling bacteria called Streptomyces," reports New Scientist. But as for why these bacteria produce these odors, researchers at the Swedish University of Agriculture Science in Alnarp discovered that the smell seems to attract invertebrates that help the bacteria disperse their spores. From the report: Paul Becher at the Swedish University of Agricultural Sciences in Alnarp and his colleagues set up field traps in woodland containing colonies of Streptomyces. They thought that the smell may act as a signal to other organisms that they are poisonous, because some bacteria like Streptomyces can be toxic. Instead, the smell -- which comes from gases released by Streptomyces, including geosmin and 2-methylisoborneol (2-MIB) -- seems to attract invertebrates that help the bacteria disperse their spores. Becher and his team found that springtails -- tiny cousins of insects -- that feed on Streptomyces were drawn to the traps containing the bacterial colonies, but weren't drawn to control traps that didn't contain Streptomyces. By comparison, insects and arachnids weren't attracted to the traps containing Streptomyces. The findings have been reported in the journal Nature Microbiology.
Did the control traps still contain soil? (Score:2)
Living soil too?
Becauae if those traps were empty, or dead, I can tell you why it didn't attract anything!
Where the Rain Gets it's smell (Score:3)
Why you can smell rain [earthsky.org]
I suspect these two stories are different takes on the same thing.
My favourite.... (Score:5, Interesting)
... is the "smell of metal / blood". I figured that it wasn't actually metals themselves (iron, copper, etc) that have that smell, since they don't evapourate (and metals that do, like mercury, are odourless). I figured that it was an oxidation product getting in the air. I wouldn't have guessed that you're actually smelling yourself, that the metals are catalyzing the conversion of lipids from your skin into aromatic aldehydes and ketones (for example, 1-octen-3-one).
Re: (Score:3)
Oh man, I always wondered what the deal was... so many questions. Research time.
So this link has some good info. I bet it also explains why if you get raw garlic on your fingers, rubbing your fingers over a stainless steel knife under tap water seems to get rid of the garlic smell. It's a similar smell so it blends in or masks it.
https://chemistry.stackexchang... [stackexchange.com]
"The âoegarlicâ metallic odor (see Supporting Information) of the gas product from the acidic dissolution of cast iron is dominated by t
Re: (Score:2)
Invertibrates (Score:2)
Advice to bacteria: To each their own, and I'm not a speciesist, but my God invertibrates are ugly. Have you ever seen a cockroach?
Re: (Score:2)
Have you ever seen a butterfly?
dirt vs soil (Score:5, Informative)
Dirt is sandy grains of rock/metal/debris.
Soil is dirt that has biology in it.
Springtails, not insects anymore?! (Score:2)
Springtails, you lost your old classification as insects?! Well I didn't know that. This stuff is interesting. Whenever I eat beansprouts I swear they just taste like bitter dirt water. Maybe the same bacteria are to blame.
Re: Springtails, not insects anymore?! (Score:2)
It seems to be working (Score:2)