Science Buddies: "Ask an Expert"

Hi.

I was having trouble with finding research on my topic.
I was wondering if anyone could help me with how to test for bacteria (E. Coli or any other kind of bacteria) in the sand, not water, of beaches.
I found how to test for bacteria in the water, but I can't find anything about testing for bacteria in the sand.

Any suggestion, tips, hints, ideas?

Thanks!

Hi,

Here is a paper describing the study of bacteria in dried mud and sand samples:

http://www.biolbull.org/cgi/reprint/74/1/56.pdf

I hope that gives you a few ideas on how to proceed.

Best wishes for a great project!

Barrett Tomlinson

Thank you so much!! This was incredibly helpful!

On page 2 and 3, the experiment describes the procedure. Do you have any idea what the plate method and what kind of solutions/chemicals are involved?

Do you also think that I should have a mentor to supervise me?

Thank you!

Hi,

I am not sure what the plate method is exactly, but here are some good candidates:

Pour plate method:

http://filebox.vt.edu/users/chagedor/bi ... ounts.html

http://aem.asm.org/cgi/reprint/18/6/1092.pdf

http://www.studentsguide.in/microbiolog ... ethod.html

Spread plate method:
http://a-s.clayton.edu/furlong/BIOL3250 ... 0plate.pdf

From the general description in the paper I suspect they were talking about the spread plate method. Since both methods determine a measure of total viable bacteria in the sample, both seem to be basically appropriate for the task.

Hope this helps.

Barrett Tomlinson

Hi,

I'm currently undergoing a project where I am trying to find bacteria (any kind) in the sand of beaches, not water. I'm also trying to correlate this to human activity to see if the amount or types of bacteria I find will affect human health.

I don't, however, have any idea how to find bacteria in sand. I know that there are many things you can do to find bacteria in water (such as coliscan gel, petri dishes, etc), but does anyone know how to find bacteria in the sand of beaches?

Thanks!!

Hi,

I'm currently undergoing a project where I am trying to find bacteria (any kind) in the sand of beaches, not water. I'm also trying to correlate this to human activity to see if the amount or types of bacteria I find will affect human health.

I don't, however, have any idea how to find bacteria in sand. I know that there are many things you can do to find bacteria in water (such as coliscan gel, petri dishes, etc), but does anyone know how to find bacteria in the sand of beaches?

Thanks!!

Hi evilelf10,
If you plan to analyze numbers of culturable bacteria using methods like most probable numbers or plate counts, bacteria can be extracted by shaking or sonication, and then the "supernatant" water above the sediments used for the counting technique.
You can try a search for "extraction of bacteria from soil" which will lead you to articles like this:
Lindahl, V., and D. R. Bakken. 1995. Evaluation of methods for extraction of bacteria from soil. FEMS Microbiol. Ecol. 16:135-142.
There are also textbooks that describe these methods.

If you haven't already, please review the precautions and requirements for working with known unknown microbes.
http://www.sciencebuddies.com/science-f ... fety.shtml
https://www.sciencebuddies.org/science- ... ents.shtml

Good luck!

Chris