Incubation of Bioluminescent Bacteria

[cunningham_h]

I am conducting the experiment: Bioluminescence: Investigating Glow-in-the-Dark Dinoflagellates, using a bioluminescent bacteria kit from Carolina. The kit requires incubating the samples for a day before viewing the bioluminescence. How would I be able to blend the two together? Do I incubate the samples as outlined by Carolina and then conduct the experiment as outlined by Science Buddies?

[deleted-141593]

Hi there,

Yes, you should follow any instructions that came with the cultures for getting them started, then proceed with your various conditions.

Cheers,
Colin

[deleted-132180]

Hello there,

Yup, that sounds like a good plan to me. However, I would probably make sure that the bacterial cultures sent to you are actually healthy because if the bacteria aren't growing, they probably wouldn't be very bioluminescent. I would probably try contacting Carolina Biologicals and tell them about the experiment you want to conduct. You should ask them whether it's fine to transfer the bacteria to photobacterium agar and grow them right away in constant light, constant dark, or light/dark conditions to make your observations, or whether you should just let the bacteria grow/recover under normal conditions overnight before using these healthier cultures for your experiment. My guess is you probably should grow out the bacterial culture that arrived overnight to make sure you get healthy bacterial cells the next day, and then use those bacteria to set up your experiment, but it doesn't hurt to ask the vendor to see what they think about it. Also, make sure that you are growing the bacteria under optimal conditions. Did the kit mention whether the bacteria need to grow at a certain temperature or environment? Did they give you detailed procedures as to how to culture these bacteria? Sometimes, if you don't put bacteria under the right conditions, they won't grow at all and you may not be able to observe anything for your experiment.

Also... have you done some research on the bioluminescent bacteria you're testing? Is this the kit you got?
http://www.carolina.com/bacteria/biolum ... /154750.pr

If this is the kit you got, then the bacteria that was sent to you is V. fischeri. Have you done a bit of research as to how and why these bacteria glow? From what I know, V. fischeri glows when they sense that the bacterial population density reaches a certain level. This "sensing" process is known as something called "quorum sensing". Hence, you will likely not see any bioluminescence when you first start the bacterial culture at low density, but once the population has divided enough and reached a certain density, you'll start seeing bioluminescence. However, I'm not sure whether anything has been done that shows that bioluminescence in V. fischeri also follows a circadian rhythm in addition to being controlled by quorum sensing, so I think it will still be quite interesting to do this experiment with V. fischeri and see whether growth in constant light, constant darkness, or light/dark will affect its bioluminescence and perhaps even growth rate, and whether these two parameters are correlated. This wikipedia article gives a pretty good, quick summary of V. fischeri bioluminescence (http://microbewiki.kenyon.edu/index.php/Vibrio_fischeri), but I encourage you to do a little more research and perhaps that may even give you more ideas to test!

Let us know if you have any more questions--we'll be glad to help!

Best,
Connie

[SciB]

Hi,

I noticed in your first post that you said you were doing the Scibuddies project, Investigating Glow-in-the-Dark Dinoflagellates but then you said you ordered a kit for growing bioluminescent BACTERIA. Dinoflagellates and bacteria are two very different organisms. Although they do both emit light, their growth conditions and experimental conditions are very different. The experiments outlined in the Dinoflagellate project were designed for a single-celled eukaryotic alga which is a photosynthetic organism. The question asked in that project was how light and dark conditions affect bioluminescence of an organism that uses light for photosynthesis. Whether light/dark cycles will affect the bioluminescence from a non-photosynthetic bacterium is unknown.

Why did you decide to order bacteria when the project called for using a dinoflagellate?

Connie mentioned quorum sensing which is a new hot area of research in bacteria and I would suggest that you read more about this subject and try to set up some experiments to test this using your bacteria.

Sybee