Lab Report Bacteria

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 purpose of this lab was to identify an unknown bacteria culture using differential tests. The identification of the unknown culture was accomplished by identifying the bacteria based on its specific metabolic characteristics and morphology. It is suggested that culture 11 is a sample of Enterobacter aerogenes.

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

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Citrobacter Freundii is a species of bacteria that can be potentially harmful to humans. It is known to cause meningitis by protruding into the brain and replicating itself (1). The Citrobacter species has also been found as a cause of some urinary tract infections, diarrhea, and even gastrointestinal diseases and symptoms (3). C. Freundii can be located in a wide variety of soils and water (3). Lastly, it is also the cause of many nosocomial infections due to its presence in water (1).

Preliminary studies help identify Genus species of bacteria. Two different preliminary study pathways must be used since two different pathogens were found in the sample. A dilution and a quadrant streak are the ideal methods to separate pure cultures of bacteria. MacConkey Agar and CAN (MAC) is a selective media that is used for the cultivation of gram negative bacteria. (PEA) is a selective media that is used

The purpose of the following study is to determine where the two unknown bacteria acquired in Microbiology lab should be classified in regards to temperature, pH level, and osmoregularity. It is important to classify bacteria in order to identify them. Identification of bacteria is important because they are not only useful but potentially dangerous as well. The identification of bacteria can lead to breakthroughs in healthcare regarding treatment of old and new diseases alike. Identifying bacteria can also be used in many other areas from better crop production through microbial pesticides to biological warfare. Their uses are endless as are their abilities to evolve and adapt to changing environments. That is why it is so important

This experiment was given to us to utilized previous knowledge learned throughout the semester to identify a gram negative unknown bacterium. We had to first learn the difference between a gram negative and a gram positive organism. We started off with doing gram stains to determine whether it was positive or negative. Based on the gram stains, a gram positive stains purple and a gram negative stains pink. A gram positive stains purple because the cell walls is made of a thick peptidoglycan layer and doesn’t

The purpose of this lab was to identify an unknown microorganism using lab techniques. The importance of identifying microorganisms is essential to the survival of humans, expansion of modern day medicine and improvement of quality of life. In 1884, Hans Christian Gram designed a differential staining technique to identify bacteria that would change the future of microbiology. He give rise to a staining process, known as the Gram stain to differentiate microorganisms into two groups between positive and negative gram staining microorganisms. The Gram stain is essential in a lab technique as it distinguishes the cells based on the physical properties of the individual cell walls, and is almost always the first test preformed to differentiate a microorganism. The identification of weather a microorganism is gram positive or negative can revel the bacteria’s virulence, cell wall structure, resistance to antibiotics, resistance to physical disruptions and so much more. In order to identify the unknown provided, unknown #27, the Gram stain was the first test preformed. After discovering that the unknown bacterium was indefinitely a gram positive microorganism, the vast possibilities were narrowed down. However, In order to more definitively identify the unknown, the next step was to preform biochemical tests. A biochemical test identifies metabolic

Gram staining is a technique used to determine if the bacteria is Gram positive or Gram- negative. Gram staining procedure uses crystal violet stain, iodine moderator, alcohol decolorizer and safarin counter stain. In Gram- negative bacteria the primary stain will be washed out with the decolorizer and it will be stained with the counterstain. Whereas in Gram-positive bacteria the primary stain will not leave the cell wall. This difference comes from difference in the structure of the cell wall that retains the stain.

The bases of this experiment was to discover the identify of the unknown from three possible specimens: Klebsiella pneumonia, Escherichia coli, and Enterobacter aerogenes. Utilizaing the T streak technique, the bacteria was isolated into pure colonies for further study. The Gram Stain method was used to identity the morhphology of the bacteria such as the shape and whether the bacteria was Gram positive or Gram negative. Biochemical test were also used to help identify the unknown bacteria. The biochemical test used was the Triple Sugar Iron Agar, Sulfur Indole Motility test, Methyl Red test, Voges-Proskauer test, Citrate test, Urease test, and the Gelatin test. After observing the morphology of the bacteria using the Gram Stain method and utilizing all the possible biochemical test, the bacteria was identified to be Enterobacter aerogenes.

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).

This experiment is about bacterial growth. We will demonstrate a bacterial growth curve using a closed system. Bacterial growth usually takes up to 12-24 hours to get an accurate result so we will be monitoring this growth between two classes. We also used different methods to determine bacterial growth as well as a few different calculations. One way of receiving data is by using a spectrophotometer where we will record the absorption at a given time to create the bacterial growth curve. We also used the plate count method after performing a serial dilution to calculate the actual cell density at different times given. By using this method we can count the population number of the same given and see the maximum cell density

2. Introduction: Each student was given unknown bacteria and was instructed to perform a variety of experimental tests that would help to identify their bacteria. During the process of identification, the unknown bacteria was added to many different testing medias using aseptic technique. They are as follows: lactose fermentation on eosin methylene blue (EMB), TSI (Triple Sugar Iron agar), Phenol red sucrose, the SIM test, H2S by SIM, IMViC (indole, motility, voges-proskauer, and citrate), Urease (urea broth), PDase (Phenylalanine Deaminase), Lysine Decarboxylase, and Ornithine Decarboxylase. Colonial morphology on EMB was used to

Another purpose of this experiment is to stress the importance of knowing the identity of a microorganism. Knowing the species of microorganism present in a sample provides a