Techniques Used For All Procedures During The Unknowns Exercise

The following tests according to the lab manual were performed: gram stain, fermentation tubes, methyl red, vogues proskauer, sulfur, indole, motility and growing it up on MacConkey agar. The gram stain was performed incorrectly the first time. This is because the decolorizer was not on the bacterium slide for long enough, giving a false outcome.

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 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.

In this experiment, we were given a sample of an unknown bacterium and asked to classify it based on its physical and metabolic properties. We hypothesized that the unknown organism was Alcaligenes faecalis, a motile Gram-negative bacillus that resides in water, soil, blood, urine, and feces (Herrera n.p.) It was first isolated in 1896 by Petruschky, who

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

In this experiment, an unknown bacterium was given to each individual student. The main purpose of this lab was to identify the given unknown bacteria going through a series of biochemical tests as one of the gram negative bacteria among six different Gram negative bacteria Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa and Salmonella typhimurium. At the very beginning, streaking method; T-streak technique was used to isolate the pure colonies. For the morphological identification of unknown bacteria, Gram Stain Method was done. Biochemical tests that were conducted for the experiment

An unknown bacterium 15 was awarded and labeled at the table ready to be identified. Using the skills and test that are taught and learned in microbiology were applied into learning what the unknown bacteria culture was. There were multiple procedures and test done in order to gain all the information needed to determine which bacteria was given. In order to find what the bacteria was the first step was finding the right environment and temperature that would allow the bacteria to thrive and grow. Determining this is one of the most important steps in being able to obtain conclusive results that would allow the results of the test to be accurate and correct. Without the correct temperature and environment the bacteria will give inconclusive results which will alter and skew the end results and may lead to the wrong conclusion. By using the methods that were obtained and learned through the microbiology class allowed the skills and knowledge to determine the bacteria and execute the tests in order to determine the culture.

The objective of this experiment was to identify two unknown bacteria from a mixed culture. Which was done by using the aseptic technique which was very important to avoid any contamination and keeping the workspace clean while culturing bacteria for different tests. To start, I chose a tube which had a solution of mixed culture. I used the flame to sterilize the inoculating loop and dipped it into the tube and streaked for isolation on 2 TSA plates and placed them in an incubator at 37 for 24 hours. Next day I observed the growth of 2 different types of colonies one for each unknown on the two plates. So I picked the best one and labeled it as master plate and discarded the other plate. From the master plate, I subcultured each type of colony

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.

Plate B incubated at 25oC produced a white, opaque, waxy, and spreading bacteria colonies while plate A incubated at 37oC produced a white, thin spreading bacteria colonies (Figure 1.). Gram staining revealed that plate B contained a rod-shaped bacterium having partial pink and purple coloration with endospores. This suggests that the bacteria is a gram positive bacteria. Gram positive bacteria typically have a thick cell wall which traps the crystal violet making them appear purple. Conversely, plate A is a rod-shaped bacterium but with pink coloration.

The first step in identifying my organism was to put it on a slide, stain it, and look at it under the microscope. I used the gram stain to figure out whether my organism was gram-positive or gram-negative. When I looked into the microscope it was all pink so I determined that it was gram-negative. The organism was bacillus in shape and was single and diplo. Then I determined that I had to focus on tests specific to gram-negative organisms. The tests I chose to perform were: OF glucose test, Citrate test, H2S test, Indole test, Motility test, and Urease test. The OF glucose test concluded that the organism was a fermenter. The citrate, H2S, and Urease tests were all positive. The Indole test was negative. The organism is motile. The unknown organism is Proteus mirabilis.

By using gram staining methods, catalase, oxidase, DNase, hemolysis, antibiotic sensitivity, citrate, and SIM tests, one can determine what bacteria species are present. These tests are extremely important because they can indicate important characteristics of the bacteria species present. In order for these tests to provide conclusive results, positive and negative controls must be used for each test. The gram stain is a very important test that is the first step in separating the bacteria. Knowing if the bacteria is gram positive or gram negative can be highly sufficient for further testing. Some tests will provide better results on gram positive than gram negative and vise versa. The citrate and SIM tests were used for initial identification of the gram-negative bacteria. The indole test is part of the SIM test that determines if tryptophan is breaks down into indole and pyruvate. The citrate test determines if the bacteria can use citrate. For gram positive, further tests were required. Oxidase, hemolysis, DNase, and antibiotic sensitivity were all used in determining the gram-positive bacteria. The oxidase test determines if the

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).

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

Microbial growth can be affected by different environmental factors such as temperature, osmotic pressure, oxygen concentration and pH. Six experiments were carried out in this report testing for microbial growth against different environmental factors. Good aseptic techniques were used to prevent contamination, resulting in a uniform set of results that are in line with the literature.