Day 3

Today we removed our broth streak plate from the incubator.  The bacteria is yellow with small white colony spots. Most of the colonies are flat, but some areas are slightly raised. It smells awful!

Next, we observes the bacteriophages in the spread plates that we created yesterday.  Our instructor traced "FUS" into the bacteria with the bacteriophages.  One of the spread plates had a visible "FUS" outline.  However, the other bacteria colony did not grow.  The outline was caused by the bacteriophages (viruses that target bacteria) killing the bacteria that it was spread on. 

We then created a gram stain for both the broth bacteria and the lightswitch bacteria. To set up the gram stain, we did a bacterial smear by transferring bacteria from the streak plates to a slide and fixing it there with water and heat.  For the gram stain, we  stained bacteria with crystal violet stain and Gram's iodine then decolorized it with ethanol.  Then we covered the bacteria smear with safranin and viewed it under the microscope using the oil emersion lens. 
Here is the safranin staining the gram stain:

The bacteria from the broth streak plate was lightly colored red.  The red coloration indicates that the bacteria is gram negative.  In the picture below, the bacteria is difficult to see, but the red stains indicate bacteria.

The bacteria from the lightswitch was colored deeply red indicating that it is gram negative bacteria.
Notice the circular shape of the bacteria.