Unknown microorganism G
Staphylococcus epidermis
\Microbiology 205
May 2, 2014
Jeanette Gill
Cheryl Davidson
Alexandra Roman
Ulani Porter
In prior weeks leading up to this date many experiments were conducted upon an unknown microorganism in which was referred to as “G”. The experiments in which were conducted showed things such as; the characteristics of the unknown microorganism, whether or not the unknown microorganism produced enzymes needed to produce gases, break down varieties of sugars, along with whether or not the unknown microorganism was a mixed acid fermenter or glucose fermenter. All experiments were conducted while using aseptic technique. .
While unknown microorganisms surround individuals on a daily basis, the only question is, whether or not if they are harmful.
The first week of experimenting started April 7 2014. The unknown microorganism was sub cultured before any experiments were performed every time in order to prevent contamination of the culture. The first experiment which was conducted was a Gram stain. The results of this experiment showed the unknown microorganism "G" was a gram positive coccus.
The second experiment was a continuous Streak conducted on a TSA plate, to identify if the culture was pure or mix. The results of this experiment concluded that G was a pure culture.
Other characteristics of G were; the colony appeared white in color, flat in elevation, circular, shiny in appearance, and small in diameter. After performing the first two experiments, the biochemical testing began the same day.
The first Week of biochemical testing started with which was conducted was the phenol red broth, which was performed in a broth, which in addition also contained a Durham tube. This experiment was conducted on a differential medium in which in addition had carbohydrate:
Dextrose (also known as glucose), lactose, mannitol, and sucrose added. The results showed that sucrose fermented the sugar and acid was produced giving the appearance a bright yellow color, but there was no gas produce during this time. Lactose also fermented sugar and produced acid
appearing to be an orangish yellow color, yet no gas was produced. Mannitol did not ferment the sugar, may or may not have used the peptone in the media causing the pH to go up and turning the appearance dark red in color, and also did not produce gas. Dextrose also known as glucose did ferment the sugar and produce acid giving birth appearance a yellow color there was also no gas produced in this one either. The IMVIC stands for four tests the indole, methyl red, VogesProskauer, and citrate which were conducted in a broth. These experiments can identify the intestinal bacteria which can cause food borne and water borne disease. The next test which was conducted what's this MR-VR test also known as the methyl red test and the Voges-Proskauer test. The MR test is conducted in a broth which methyl red indicator dye is added. The broth turns red at a pH of 4.4 and yellow at a pH of 6.2. This experiment appeared red in color proving a positive result. Meaning that the unknown microorganism G was a mixed of Acid fermenter.
The Voges-Proskauer test is designed to detect organisms that are able to ferment glucose yes are able to convert their acid products to acetone 2-3 butanediol quickly. The result appeared pinkish in color therefore making it a positive result, proving that the unknown microorganism was capable of butanediol fermentation. An additional experiment which was conducted during this week was the catalase test carried out on a slant. This experiment checks for the unknown microorganism's ability to complete aerobic respiration, which is the ability to convert hydrogen peroxide to water in oxygen gas. This experiment produces bubbles, therefore making a positive result. The final experiment conducted during the first week of biochemical testing was the oxidase test. This post was also an aerobic respiration test. The last enzyme of the
