Unknown Microbiology Report

The purpose of this lab was to identify two unknown bacteria from a mixed culture. The reason for identification of unknown bacteria was to help students recognize different bacteria through different biochemical tests and characteristics. This is important in the medical field because identification of unknown bacteria can help treat a patient by knowing the contributing source of a disease. Also knowledge of different bacteria helped others make antibiotics used today. This lab was completed by using the methods learned thus far in identification of bacteria.

My unknown organism #6 is Morganella morganii, which is a gram-negative bacillus rods commonly found in the environment and also in the intestinal tracts of humans, mammals, and reptiles as a normal flora. (3, 5) This bacterium Morganella morganii, was first discovered in the 1906 by a British bacteriologist named H. de R. Morgan. (2) Despite its wide distribution, it is an uncommon cause of community-acquired infection and is most often encountered inpostoperative and other nosocomial settings. (2, 3) Morganella morganii infections respond well to appropriate antibiotic therapy; however, its

The purpose of this lab was to identify two unknown bacteria cultures using various differential tests. The identification of these unknown cultures was accomplished by separating and differentiating possible

|EMB Agar | |Distinguishes bacteria that ferment |Dark blue colonies with|E. coli and P. |

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

An unknown was given to our group from the professor. The unknown was in nutrient broth, the group received unknown number 3. And the task was to identify the unknown and try to make an educated guess, and identify the unknown #3.

The identification of an unknown sample, particularly in the environment, can be the matter of life or death. Identifying an unknown environmental sample has countless of opportunities and benefits. Identifying pathogens in the environment can save the lives of thousands or even millions of people. Some bacteria are opportunistic pathogens such as Pseudomonas. These pathogens do not commonly infect healthy people, but rather take any opportunity possible such as an open wound or an immunocompromised system. Knowing the bacteria which can prevent or promote the growth of agriculture can help to feed populations. Being able to identify bacteria is a task not to be taken lightly. Many different tests are possible to determine a specific bacterium. Often it takes a combination of several different tests to narrow down and identify a specific genus and species.

The next step in identification was to run a TSI test to determine whether or not the bacteria were able to ferment lactose, sucrose, and/or glucose and if Hydrogen Sulfide was produced by the bacteria. The TSI agar was stabbed with the pale pink bacteria and the slant was streaked. Following incubation, the slant was red in color (alkaline) and the butt yellow (acidic.) This meant that the bacteria were only able to ferment glucose. This was consistent with the initial finding from the MacConkey agar, that the bacteria were not lactose fermenters. The next step was to conduct an MIO test. After incubation it was determined that the bacteria were motile, which presented as turbidity in the tube. Ornithine decarboxylase was present in the medium, causing the bottom of the tube to turn purple. After the addition of Kovacs’ reagent, the surface turned bright red, indicating the presence of Indole. The next step was to perform a citrate test to differentiate between two types of bacteria, Clostridium difficile and Morganella morganii. The slant of Simmons citrate agar was streaked with the unknown bacteria. Following incubation, the color of the slant remained green indicating that the bacteria was not able to use citrate as a source of carbon and energy. The bacteria could then be identified as Morganella morganii. A urease test was used to confirm this result since Morganella morganii is known to produce urease. The urea agar slant with phenol red indicator was streaked with the bacteria. Following incubation, a color change was observed indicating the bacteria were able to split urea into ammonia and carbon dioxide, creating an alkaline

The Catalase tests involves exposing the colony of interest to hydrogen peroxide to check for the presence of the enzyme Catalase. If the bacteria contain the enzyme, exposure to hydrogen peroxide will trigger the breakdown of it by Catalase as a defense mechanism against the harmful substance. Catalase test positive genera include Bacillus, Micrococcaceae, and Staphylococcus, while Clostridium and Streptococcaceae test negative (Holbrook and Leicht, 2015). The second test administered to gram-positive bacteria is the Mannitol Salt Agar (MSA) test. This test involves observing growth of the bacteria on the MSA medium, which contains very high amounts of sodium chloride. The only strain capable of growth is Staphylococcus, which causes the medium to change in color from red to yellow, indicating fermentation of the

Bacteria is an organism that can be a nuisance to human beings as well as a necessity. Among biologists and scientists alike, pathogens have been the number one focus, determining the optimal growth conditions that certain bacterial require in order to replicate efficiently. It should be noted that previously, bacterial cells were hard to examine and analyze however, evolutionary advancements in the biological field including the improvement in microscopes, allowed biologists to envelop a better understanding of the physiological properties of these bacterial cells. The experiments conducted are aimed to determine the effectiveness of environmental control including the alteration of pH, osmotic pressure, as well as temperature on specific

Identification of bacteria is important for a verity of reasons, determining if a bacteria is normal flora, or potentially pathogenic as well as determining the bacterial source of an infection or outbreak. Identifying the bacteria is crucial when treating a bacterial infection because the correct antimicrobial or antibiotic must be used to successfully eliminate the infection and this cannot be done without the identity of the bacteria. Selecting the correct antibiotic is critical when dealing with an infection since not all antibiotics are equally effective against bacteria. Finding the identity of the bacteria causing the infection allows the doctor to prescribe the appropriate antibiotic. Unfortunately looking at only cell or colony morphology cannot lead to a conclusive result because there are many similarities in colony and cell morphology even among the eight bacteria used in this experiment.

Microbiology begins with Robert Hooke in his discovery of a very important part of biology in the year of 1665. He observe while looking through a microscope that life existence of small structural units referred to by Hooke as "little boxes". Hooke constructed his own version of a compound microscope which had two lenses instead of one. He viewed individual cell like structures through the lens marking the beginning to "Cell Theory”. Hooke microscope lacked the capability of resolution and it wasn't able to show large cells either.

In this experiment, three strains of bacteria were identified from a mixed bacteria culture. In order to determine the identity of the bacteria, selective and differential media tests were performed. Some of the medias used for testing were MacConkey, Eosin Methylene Blue Levine, Salmonella-Shiegella, Tryptic Soy Agar, Citrate, TSI, among others. Gram-stains were also used to observe the morphology of bacteria under the microscope. The identities of the unknowns were determined by comparing the results obtained with characteristics of possible species that are determined in the literature. The results pointed out that unknown A was Escherichia coli, Unknown B was Yersinia enterocolitica, and Unknown C was Staphylococcus epidermidis.

From the air we breathe to the water we drink to the food we eat, there are thousands upon thousands of bacteria that we interact with on a daily basis some are good and help us live healthy and productive lives, like the bacteria that is used to make and keep yogurt from spoiling (Wassenaar, 2002) . Now granted, not all bacteria are beneficial to us and can cause us a lot of harm. If bacteria are harming us, either by causing disease, contaminating our food, or harming the environment that we live in, one needs to identify the unknown bacteria so that the proper treatment and strategy can be developed to remedy the problem (Intrieri, 2014). In order to identify bacteria and other organisms, scientists have developed many different tests to differentiate microorganisms from each other their physical characteristics.

Bacteria biochemical testing can determine the types and numbers in terms of colony forming units of bacteria present in a sample of different chemical. The testing could be focused on a specific type of bacteria, medical bacteria or a broad range of environmental bacteria. Since bacteria are present in virtually any environment, it’s important to be clear why the