Our Cultures from the Marina & Isolation of the Air Sample

Our Cultures from the Marina

Isolation of the Air Sample

Class: Tuesday, September 3, 2013

Lab partners!

We started by inspecting our two samples from the Marina - the air sample and the boat sample.

Steubenville air sample

Boat sample

We were surprised by the different colored microbes growing in the Steubenville air agar plate! We decided to get a closer look at these cultures under the microscope. As seen in the picture below of the magnified air sample, some of the bacterium are shiny.  This can mean that they are surrounded by a slime capsule.  Some bacteria exhibit this property for protection and for better adherence to surfaces.

Magnified air sample

Magnified boat sample

Touching loop to bacteria for pure culture

We then decided to grow a pure culture of the Steubenville air sample. To do this, after we sterilizing, we touched the inoculating loop to three different types of bacteria growing on the plate, distinguishable by color and shape. 

Next, to isolate the bacteria and grow a pure culture, we followed the streak pattern as follows:

How to streak the plate for pure culture

We moved the loop in a quick zig-zag pattern in four zones along the plate, ending with a squiggle in the middle.

Streaking bacteria for pure culture

Pure culture: before growth!

After streaking the plate with the bacteria from the air, we placed it in an incubator, set at outdoor temperature. 

We are excited to see what the results will be!