Bacteria help!!?

Question

OKay! For my AP Biology class, we have to make up an experiment for an inquiry project. Mine was studying how much bacteria grew after being cleaned with brand name and generic brand cleaning products.

We did our 1st set of testing the other day (Tuesday) and today we examined it.

The bacteria or unknown growing bacteria of culture we took

it looks like

lots of small white fuzzy little colonies of bacteria or I have no idea what.

I have been trying to figure out what the bacteria is by looking at it.

Anyone have any ideas what the bacterica or culture could be. I have been looking on line fore a few hours nows and have gotten not so far.

So I would like peoples ideas on what it could be or if you know a good site I can look at!

Thanks!

Also we cleaned and took cultures from around the sink handles in the school bathroom

Answer 1

Identifying bacterial species is a nearly impossible task unless you can narrow it down based on the source. If it came from your skin it is most likely Staphylococcus, but you would need to look at it under a microscope (they are round balls), and probably do a gram stain (I think they are gram positive), and you still wouldn't be sure exactly what it is. To determine the species exactly, you would need to do a genetic analysis, but knowing the exact species of bacteria that grew isn't that important to your results, unless you are interested in whether the product kills a specific species.

Fuzz or hair usually indicates mold or a fungus of some kind, but without seeing it, my money's on staph - it's so common, it's everywhere.

Answer 2

If you have just a generic agar plate, there is almost no way to tell what it is just by looking. Some species are more common than others, of course, and some hang out in some places more than others. But that would pretty much be total guesswork.

Generally how someone would determine what specific species a particular culture was would be to look at it under a microscope or try growing it on a number of other plates that would narrow down your choices on the basis of biochemistry. Either of which is probably more work than you're interested in doing.

I would suggest just getting colony population counts and stating for your project what common bacteria can be found wherever it was you got your samples from and wherever it is you live. There are literally hundreds of possibilities in all likelihood!

Answer 3

That's not enough info to even make a guess... Here's something simple you can do to narrow it down A LITTLE.. Place a drop of 3% Hydrogen peroxide on one of your colonies, if it bubbles that means it's catalase positive, if there are no bubbles then it's negative. A gram stain and some other simple biochem agars would be very helpful..

I assume you're not using any kind of blood agar, if you are then you will want to remove a colony aeseptically from that to a glass slide so you don't get a false positive..

Answer 4

You took some cultures. So I think you've got the stuff to determinate the cultures. Agarplates, microscope and Gram staining stuff ready? Here we go!

Small white and yellow strains:
Make a slide of the strain you want to know (count all the strains, as one species, if they look the same) and follow the Gram staining protocol.
*If it's a Gram negative cocci (O-form, pink), I dunno what to do.
*If it's a Gram positive cocci (O-form, purple), graft the strain to a new plate and put some bacitracine or furazolidone on it (sterile!)
>>
*If the strain is sensitive to furazolidone and not to bacitracine, and it can make H2O and O2 (bubbles!) out of H2O2 (hydrogenperoxide? Used to colour you hair...), it's a staphylococus species
*If the strain is sensitive to bacitracine and not to furazolidone, and it can make H2O and O2 out of H2O2, it's a micrococcus species
*If the strain can't make H2O and O2 out of H2O2, it's a streptococcus species
****
*If it's a Gram positive rod ( | -form, purple), and a sporeformer it's a Bacillus species
*If it's a Gram positive rod ( | -form, purple), and NOT a sporeformer I dunno what it's
*If it's a Gram negative rod ( | -form, pink), you may cal it a member of the Entrobacteriaceae-family - you should use some more tests to get the name of the species
*If it's a Gram positive rod ( Y -form, purple), incubate at 37 and 55 degrees
>thermophiler Actinomycet only lives at 55 degrees
>if it's lives at 37 and 55 degrees it's ... (there is a name for it, but I dunno at the moment)

Other species are unidentified

Answer 5

Try this:

http://science.jrank.org/pages/711/Bacteria-Identifying-classifying-bacteria.html