Julia said:
>>Actinomycetes (the common soil microbe that contributes so much to the
earthy smell of dirt, both in and outside of caves).
>Now I may know the "secret" ingredient in my "Cave Passages" candle
that I purchased from an ICS vendor (www.speleosoap.com). The smell of
this candle is EXACTLY like a cave passage!
I don't know whether it is also made by actinomycetes (it seems to
mainly come from streptomycetes), but one of the compounds responsible
for the odor of dirt is called geosmin:
<http://en.wikipedia.org/wiki/Geosmin>. It is a relatively simple
molecule whose biochemical pathway has recently been elucidated:
<http://www.sciencedaily.com/releases/2007/09/070916143521.htm>.
Better living through chemistry! :-)
Mark Minton
