Lab Report Essay

An unknown bacterium was handed out by Dr. Honer. The appropriate tests were prepared and applied. The first procedure that was done was the gram stain. Under a microscope, if the gram stain is purple, the bacterium is gram positive, if the stain is red, it is gram negative. The next test was the fermentation tests for glucose, sucrose and

The Unknown Bacteria 36/Bacteria # 2 on a TSA plate was examined by the naked eye and under a dissecting microscope. Bacteria # 2 was approximately 3 - 4 mm in diameter. They were circular in form with an entire margin and a flat elevation. The colonies were rough (granular), translucent, and white brownish color with black granules. The Gram stain resulted in a Gram negative rod. After the Gram stain was completed, the bacteria were streaked on an Eosin -Methylene Blue Agar plate and an Enterotube II was inoculated.

To perform this test, a small drop of water is placed on a clean microscope slide. A metal loop that has been properly sterilized in the blue flame and allowed time to cool is used to

The next step of the project included preparing a Gram stain to discover the cell shape, arrangement, and if the bacteria is gram positive or

1) Apply the stain to your first unknown slide and examine it under the microscope.

Table 3 shows Gram stain results that indicated C. Freundii as a gram negative bacterium in rod shapes scattered in singles and some in pairs. Each gram stain produced the same results. The Bartholomew and Mittwer method of endospore staining indicated that C. Freundii tested negative for endospore formation. Table 4 shows the biochemical test results of the unknown and the official test results for comparison.

The first step toward identifying this unknown organism was to perform a Gram Stain to differentiate between gram positive and gram negative bacteria. This is an important step because it directs what the next tests will be. My Gram Stain on sample #12 showed that the bacteria was gram negative, however, after receiving the results of the OF glucose, H2S, Citrate, Urease and Motility tests, it was apparent that my Gram Stain was contaminated. I then performed a catalase test which came back negative, so I ordered a Bacitracin disc, Optochin disc and a CAMP test which had to be incubated overnight. After receipt of those test results,

The main idea of this experiment was to correctly identify the unknown bacteria, #3. Identification of unknown bacteria yields multiple benefits in many different areas in the research of microorganisms. In this experiment I performed many different test dealing with things such as the presence of enzymes, fermentation abilities and different chemical reactions. Observations made from the tests were then compared to a gram negative unknown chart in order to identify the bacteria. Based off of my results and the chart, I concluded the bacteria #3 was the bacteria Escherichia coli. E. coli is most commonly found in the intestines of warm blooded organisms. Most E. coli strands are non pathogenic however, there are strands

Two smears of the unknown bacterium #5 were inoculated while the second smear was used for a back up. The unknown bacterium dried for at least forty minutes. After the smears dried, the slides were heat fixed two times to ensure the stability of the organism. The slide was placed on top of the staining rack then over the small sink.

This report discusses the procedures and equipment needed to determine a bacterium knowing and having nothing but the sample bacteria given by the instructor. The importance of this lab is to test your ability to think clearly about what each test will tell you about your unknown organism and selecting tests that will save time and give you the most information. The objective of this lab is to determine what species level and genus level your bacterium is categorized as. The first step taken to determine the bacteria was to do a sub-culture of my stock broth to have a backup of my bacteria just in case my broth became contaminated. Doing a T-streak on a TSA plate is when the plate is divided into three sections and using an inoculating loop, grab some

To start off unknown #3, I picked out O17 from rack A and wrote down my name, date, class, and I first noticed the broth was a light yellow that was quite cloudy or milky. Soon later I streaked my organism onto a TSA plate and incubated it at 37oC for 24 hours, t was almost a perfect plate. There was no contamination; I could tell it there was only one species on the plate and that it was okay for me to move on. There were many isolated colonies in quadrants 3 and 4. The colonies were small and white in color, it was not translucent. I then began to make my 2 slants, inoculating a straight line on each slant, I incubated it at 37oC for 24 hours. The next day, I made sure my slants were pure and also there was a thick line of organism where I had inoculated with a yellow-white color. Now I was ready to begin making my slides and start staining. I used E. Coli and S. Aureus next to my unknown to help me

Unknown lab report# 24 Introduction Microbiology is a study of organisms that surrounds us every day. It requires an educational understanding to identify organisms, and the ability to distinguish different bacteria’s. In applying the learning process of the different bacteria’s, unknown bacteria samples are given to be studied and identified.

The gram stain test the most efficient and important test in microbiology (Smith & Hussey, 2013). This test is always the first test to start in microbiology to differentiate between gram positive and gram negative bacteria. The gram positive bacteria would turn purple and gram negative would turn reddish/ pink after staining with the crystal violet, iodine, ethanol, and safranin (Leboffe & Pierce, Microbiology Laboratory Theory & Application (Brief Edition), 2011). Although the gram stain proved one part of the unknown a second test was perform on a slide for the KOH test. This test is a quicker way to determine if the bacteria is gram negative or gram positive.

The bacteria that was contained within Unknown tube #12 is believed to be Pseudomonas aeruginosa, Figure 1. The bacteria tested to be Gram Stain negative, producing a pink, red color retained from the staining process. When the species of bacteria was plated on nutrient media, the cells produced an irregular and spreading configuration as shown in Figure 2. This same plating test provided the margins and elevation, lobate and hilly, respectively. The specimen was stabbed in a Fluid Thioglycollate Medium (FTM) tube using an inoculated loop of the bacteria. The results of this experimentation indicate the type of oxygen requirement of the bacteria. The test found the bacteria to be aerobic as colonies of the bacteria began to form along the top of the FTM tube (Manual 2017).

The lab manual confirmed the experiments findings to be correct and each one were pink colored on the slide under a microscope. If the result had varied from gram negative a reason could include leaving the decolorizer on the slide for one minute instead of ten seconds. Doing this could make the slide appear any color other than pink. The results could also have varied