Science Buddies: "Ask an Expert"

Is it possible to identify specific types of bacteria in water under a microscope? If not, is there another way I could?

Hello and welcome to Science Buddies!

Bacterial identification is a significant aspect of biology and there have been numerous tests developed to identify different bacterial species. Unfortunately, with visual inspection under a scope and without chemical testing, you're somewhat limited.

One of the more obvious ones is by morphology (shape): bacteria generally come in three shapes - coccus, bacillus, and spirillum (spherical, rod-shaped, and spiral-shaped, respectively). You can further analyze coccus and bacillus bacteria by the way they clump up - for instance, Staphylococcus forms little clumps of no discernible shape, while Streptococcus forms long chains. There are plenty of resources online that can help you visually identify bacteria down to a certain level.

Another common method is to look at the way they form colonies on an agar plate. If you have the resources, try streaking the bacteria from the water sample onto some nutrient agar, and incubating it for a few days. You might be able to identify different colonies forming on the plates. Then, you can consult a guide like this one: https://www.sciencebuddies.org/science- ... gar-plates

You probably will not be able to name the genus and species of the bacteria you find - that's totally fine! You will, however, be able to identify different types of bacteria that coexist from the same sample.

Please help me my project is due 3/17/09 i have a 90 min delay so i can do something that takes a while

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