Colonies of Pseudonomas aeruginosa often display similar result on this medium 2. The only gram negative bacteria that shows a positive result on the Casein Test is Pseudomonas aeruginosa, therefore correctly confirming the unknown gram negative bacteria. It is also important for students to understand sterile techniques, diagnostic steps, treatment, risk assessment, transmission, and prevention of microorganisms. In addition… process of the bacterial unknown project, vast amounts of test were performed in order to determine an unknown species of bacteria. In the medical field bacteria and infections of different kinds are the core of the practice. Two different morphologies allowed Gram stains to be performed on each of the bacterium. The purpose of this is to grow separately the 2 possible bacteria.
After determining the Gram-negative reaction, specific tests were performed. The Lab Manual for General Microbiology — Biology 203 by McDonald et. It is important for people to understand why it is beneficial for us, and even more important to understand how it is harmful. Culture 2 appeared to be solid white dots spread out on the plate. Creamy 2 — darker off white, creamy appearance growth. The streak plate was then incubated at 37 degrees Celsius for 48 hours. Moreover, gram staining was used to understand the basic morphology of these bacteria.
The Unknown bacteria is Enterobacter aerogenes B. The urease test was performed on the gram + and - bacteria, testing for the breakdown of urea. Indication of gram + bacteria. Procedures were followed as stated in the lab manual 1. Proteus is also found in multiple environmental habitats, including long-term care facilities and hospitals.
The Citrate Test was used to test for the ability of a bacteria to utilize citrate as a sole source of carbon, these bacteria produce citrate permease which can transport citrate into the cell and make pyruvate from it. This narrowed it down to both of the Bacillus species. They would be in the Results section. When observed, there were both gram-positive rods and gram-negative rods. A urea test was conducted which came back negative and took Klebsiella pneumonia off the list. The purpose of doing so ensures that we have pure cultures of the unknown to be used in further testing and not a mixed culture. The writing should be simple and easy to understand.
The methyl Red test was used to show which bacterium would be able to produce a mixture of acids that would ferment glucose. A gram stain was done originally and found red rods identifying the bacteria as gram negative. Escherichia coli, also known as E. The differential tests used to identify the unknown cultures were Each person in the class was given a heterogeneous broth mixture of 2 microbes. Lab Manual for General Microbiology: Bio 203. Catalase trial Consequences Table 1. Similar consequences are characteristic of P.
The Gram stain showed it was Gram positive rods. To find if the being is motile or non-? See Table 1 and Flow Chart 1 for results of Bacteria 1 and Table 2 and Flow Chart 2 for results of Bacteria 2. In my case I had a gram negative bacteria. An unknown bacterium was handed out by Dr. The unknown tube, 125, was isolated in order to grow two separate cultures. Alt 5 was given as a substitute for a gram-negative bacterium, due to no growth in original test tube 122.
The colonies were rough granular , translucent, and white brownish color with black granules. These bacteria must be able to be identified in order to treat patients properly, efficiently and safely. I feel that this lab was very good for students such as me to see what microbiologists do on a daily basis. First the unknown tube was isolated. There was only one type of bacteria that grew. Table 1: Tests and Results for Gram Negative Bacteria Test Purpose Reagents or Media Observations Results Gram Stain To determine whether the bacteria was gram negative or gram positive Crystal violet, Iodine, Alcohol, Safranin Red Rods Gram Negative bacteria Casein To determine if the enzyme casease was produced to break down the milk enzyme casein Milk Agar white opaque Milk Agar changed color where bacteria was smeared, turning a brown color Positive, the bacteria produced casease The first test performed on the gram positive bacteria was the Nitrate Test which turned red after adding reagents giving a positive result meaning the bacteria reduced nitrate into nitrite or something further. The Iodine here acts as Mordant.
After observation there was a clear positive result, which showed the bacteria produced casease. Then a urea test was performed to check for the production of urease. The following study was performed using all of the methods used in general microbiology laboratory class. This deduction was reached for a couple reasons. This step is imperative because the bacteria need to be separated and isolated before they can be identified. The bacteria is Staphylococcus Aureus.
Because they were growing right next to each other, it was very possible to pick up both bacteria. The search began with the identification of the bacteria as being rod shaped under the light microscope. Some other ways include, having physical contact, contact with animals and high fiber diets 2. Retrieved December 2, 2013 , , , ,. The other bacteria which was microscopically viewed as gram positive was missing in the incubator, another tube of sample was derived from the lab professor. In order to begin to understand them, we must learn the basics.