I spy with my very own eyes

     This week I worked on identifying my unknown microbe. I received a test tube labeled 90210. (To mark the beginning of this challenge I played the theme song from Beverly Hills 90210 by Liz Phair.) After listening to the aforementioned beautiful arrangement I got straight to work. I performed the following test with the following results:

Test 1:

Colony Morphology

     I specifically wanted to see the shape of the colonies, the colony edge, elevation, colony pigment, and smell. I did an isolation streak on a TSA plate, placed the unknown microbe in the proper place, and very impatiently waited to see the results.  When I got the results I noted the microbe was circular in shape, the colony edge was small/entire the elevation appeared slightly raised, it was off white/ beige/ and opaque in color and I couldn’t accurately identify the smell. 

Test 2

Gram Stain

     I decided I wanted to do a gram stain and look at the microbe under a microscope. I found the microbes to be gram negative bacilli.

Test 3

Oxidase test

     I was confident in my microscope identification, so I did not streak Macconkey Agar or Mannitol Salt Agar, (keeping in mind that I would do a SIM Test.) So, I did an oxidase test. The results of the oxidase were negative meaning the unknown bacteria didn’t possess the cytochrome oxidase (CO) enzyme. In fact, before the Oxidase test I had a nagging suspicion “90210” was Pseudomonas aeruginosa. Not without the (CO) enzyme though!

Test 4

Glucose Fermentation Test

     Following the negative oxidase test I moved to the next test, the Glucose Fermentation Test. I was looking to find out if the microbe fermented simple sugars into acid and/or gas. Following the test, it was determined the bacteria was positive for acid fermentation but was negative for gas production.

Final Test

SIM Test

     Since the microbe was positive for acid I moved to the Sulfur Reduction Indole Production and motility test (SIM Test.) I was suspicious the bacteria I had was Escherichia coli but wanted to confirm this by testing to see if it was negative to reducing sulfide and positive to motility. Following this test my suspicion was confirmed I was sure I positively identified bacteria known as Escherichia coli.

 Side note:

 Knowing that I accomplished the challenge I played “Love that Dirty Water” by the Standells.