Fun with Soil – Jill

Where did you obtain your soil sample?
My soil sample came from an old cedar sawmill site in the Adirondacks.  The mill was probably active in the 1920s and 30s, so while nothing remains of the mill itself, the deep pile of sawdust has settled and lacks any growth.
Why did you choose this location?
I was curious – I wouldn’t think was was a “rich” site, but might have some very selective types of microbes.
Do you expect a lot of isolates? Why or why not?
Not really. I figured the site was toxic, since after almost 100 years no trees or other plans have colonized the site.
Have you initial observations supported this?
Well – I was surprised how much grew, but I did plate the original suspension (the “no dilution” sample) as well as the 10 -1 and 10-2. But my cfu is relatively low – around 106 cfu/g.
What media did you choose? How did you sample differ on the different media?
Well – I did try all the medias to see what kind of differences I might see. I actually got more growth on the less nutrient media. Both LB, AC and R2A were very similar – low growth ( LB was 4.5 x 105) with mostly white plain looking colonies, very little diversity.  PDA definitely had the most diversity with a number of dark pigmented colonies – from dark brown to tan to reddish brown. I picked more form this plate as a result.  The 10% TSA had diversity, but less with pigment, some looked liked they might be filamentous. I saw no mycoides on the plates.
What dilutions?
(see above)
Will you need to redo any? I did plate a 10-3 dilution of each, but I don’t expect much more. As of 24 hours, nothing has grown.

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