Science Buddies: "Ask an Expert"

We need to cultivate bacterial colonies that are found inside most sea sponges. After some extensive research on the topic, we found that we need marine broth agar plates for the bacteria to grow on. Please help. We need to know the neccessary materials and a procedure.

Hi Matt,

Here are two sites that give general information for preparing agar plates. The secret to preparing good agar plates is to let the agar cool down to about 55 degrees C (lukewarm) before you pour the sterile agar into the Petri dishes. I would recommend making just a small batch the first time you try this. You could use the general procedures described here to grow and count bacteria from sea sponges. Do you have a way to sterilize the agar so you can prepare the marine agar plates? Do you have access to a microbiology laboratory to work in?

http://www.marine.usf.edu/microbiology/ ... 1SUSHI.pdf

Now, what are you going to do with the sea sponge bacteria? Are you going to count them? Are you trying to identify a particular bacterium? Let us know if you need more information.


Donna Hardy

As a gentle reminder, remember that you need SRC approval before working on any potentially pathogenic substance (except for E. coli or S. cerevisiae). I'm posting the link for SRC forms in case you need to fill them out.

http://www.sciserv.org/isef/document/

With regards to pouring agar plates, do you have access to an autoclave? This is the easiest way to sterilize the media and liquify it before pouring the plates. Boiling agar is not always so easy since it has a tendency to boil over and froth. Another alternative is to purchase pre-poured plates online. A simple google search should help you do this.

Best of luck,
Linh

Hi there,

Sounds like an interesting project!

You can buy Difco Marine Agar 2216 from various sources.

http://www.bd.com/ds/technicalCenter/in ... h_2216.pdf

You need access to an autoclave to make this media.

Here are some links to procedures for pouring agar plates - there are many more if you do a google search, but these should give you a good idea of the procedure:

http://en.wikipedia.org/wiki/Agar_plate
http://hcgs.unh.edu/protocol/basic/Clagar.html
http://www.sciencestuff.com/playground/ ... ttle.shtml

How are you going get the bacteria off of/out of the sponges? Are you going to rinse the sponges with sterile water and plate it on your Marine Agar? Something to think about.

You may also want to do some research as to the types of bacteria that are usually found in sponges - are these bacteria pathogens (disease causing)? If so, you will want to be very careful and work in the appropriate environment, also you will have to get approval as indicated by Linh. I would suggest doing some background reading before you start.

Good luck and let us know if you have any more questions.

Mary