Melvin Johnson Unknown Lab #1 Unknown#10 E. Coli Abstract There are many reasons for identifying an unknown bacterium. The reasons range from medical purposes, such as determining if the unknown could cause ailments in living things or knowing what microorganisms are present and what antibiotics are needed. The purpose of an unknown lab is to identify an unknown bacteria culture using a number of differential tests. The tests performed on the unknown bacteria cultures were all used to determine the identity of the bacteria.
Each of the tests performed provided some key information about the bacteria in question and how it function Identification of the unknown cultures was accomplished by sorting out and differentiating possible bacteria based on specific biochemical and morphological characteristics. The tests performed and materials used identified specific enzymatic reactions or metabolic pathways. Each test used helps to recognize the particulars and identify the unknown bacteria.
The tests used to identify the unknown cultures were THIS Ism’s HAS, Indolent, Motility, Glucose fermentation, UP, Citrate, Areas, Gelatin, Nitrate NON reduction, Catalane, Casein, and Starch. Physiologically, E. Coli is versatile and well-adapted to its characteristic habitats. It can grow in media with glucose as the sole organic constituent. Wild-type E. Coli has no growth factor requirements, and metabolically it can transform glucose into all of the macromolecular components that make up the cell. The bacterium can grow in the presence or absence of 02.
Under anaerobic conditions it will grow by means of fermentation, producing characteristic “mixed acids and gas” as end products. However, it can also grow by means of anaerobic respiration, nice it is able to utilize NON, NON or fumigate as final electron acceptors for respiratory electron transport processes. In part, this adapts E. Coli to its intestinal (anaerobic) and its extraterrestrial (aerobic or anaerobic) habitats. Unstained cells of E. Coli viewed by phase microscopy. About magnification. CDC. Nine reactions, each catcalled by a specific enzyme, makeup the process we call glycoside.
ALL organisms have glycoside occurring in their cytoplasm. At steps 1 and 3 TAP is converted into ADAPT, inputting energy into the reaction as well as attaching a phosphate to the glucose. At steps 6 and 9 ADAPT is converted into the higher energy TAP. At step 5 AND+ is converted into NADIA + H+. The process works on glucose, a 6-C, until step 4 splits the 6-C into two 3-C compounds. Clearheadedly phosphate (GAP, also known as phosphoglyceraldehyde, PAGE) is the more readily used of the two. Dehydrogenation phosphate can be converted into GAP by the enzyme Isomerism.
The end of the glycoside process yields two pyrrhic acid (3-C) molecules, and a net gain of 2 TAP and two NADIA per glucose. When bacteria grow in aerobic environments, the terminal electron acceptor 02) is reduced to water by an enzyme called an oxides. When bacteria grow in anaerobic environments, the terminal electron acceptor is reduced by an enzyme called a reeducates. In mitochondria the terminal membrane complex (Complex IV) is stockroom oxides. Aerobic bacteria use a number of different terminal oxides. For example, E. Coli does not have a stockroom oxides or a Bcc complex.
Under aerobic conditions, it uses two different terminal quinoa oxides (both proton pumps) to reduce oxygen to water. Anaerobic bacteria, which do not use oxygen as a terminal electron acceptor, have terminal educates individualized to their terminal acceptor. For example, E. Coli can use fumigate reeducates, nitrate reeducates, nitrite reeducates, DMS reeducates, or thermodynamic-N-oxide reeducates, depending on the availability of these acceptors in the environment. Most terminal oxides and reeducates are inducible. They are synthesized by the organism as needed, in response to specific environmental conditions.
Nitrate reduction Some microbes are capable of using nitrate as their terminal electron accepter. The TEST used is somewhat similar to aerobic respiration, but the terminal electron transport protein donates its electrons to nitrate instead of oxygen. Nitrate reduction in some species (the best studied being E. Coli) is a two electron transfer where nitrate is reduced to nitrite. Electrons flow through the quinine pool and the stockroom b/CLC complex and then nitrate reeducates resulting in the transport of protons across the membrane as discussed earlier for aerobic respiration.
NON- + e- + EH+NON-+ H2O Figure 1 – The reaction for nitrate reduction. NON-, nitrate; NON-, nitrite This reaction is not particularly efficient. Nitrate does not as willingly accept electrons hen compared to oxygen and the potential energy gain from reducing nitrate is less. If microbes have a choice, they will use oxygen instead of nitrate, but in environments where oxygen is limiting and nitrate is plentiful, nitrate reduction takes place. One such concern turned into a serious outbreak in Walker, a small rural town in southwestern Ontario with a population of about 5,000.
In May 2000, many of Walker’s citizens began to fall ill, experiencing stomach cramps, diarrhea, fever, nausea, and vomiting. E. Coli characteristics I * Prokaryotic * Gram-negative * Capable of aerobic and anaerobic diabolism * Heat-labile at high temperatures I Seven people eventually died and about 2,300 others contracted the ailment, which turned out to be an E. Coli 0157:HE infection. The municipal water system had inadvertently dispensed a toxic brew of the bacteria to Walker residents.
Without wanting to, Walker turned into an example of the importance of understanding the biology behind E. Coli so that scientists can What is E. Coli? E. Coli is a single-celled organism belonging to the large bacterial family Interchangeable, the enteric bacteria. Its genus name, Escherichia, is derived room the name of its discoverer, German physician Theodore Escherichia, who in 1885 first isolated and characterized the bacterium. ‘Interchangeable’ originates from the Greek word enteritis, meaning “that which pertains to the intestine. Medically, the Interchangeable are one of the most important families of bacteria because its members are the most frequent cause of urinary tract infections and are a serious wound pathogen. A number of genera within the family include Salmonella, Shillelagh and Yearnings, which are human intestinal pathogens. Several other Escherichia species are normally mound in the human gastrointestinal (GIG) tract. Left: E. Coli cells are rod-shaped and flagellated. Right: E. Coli colonies grow readily on an agar plate. Courtesy of University of Wisconsin-Madison Department of Bacteriology, 2002,http://www. Back. Wish. Due/Baccarat/lectureship) I E. Coli is the predominant facultative organism in the human GIG tract, which means that E. Coli can grow and metabolize glucose in both the presence of oxygen (aerobic conditions) and the absence of oxygen (anaerobic conditions). The bacterium protects the intestinal tract from potentially harmful bacterial infections, aids in digestion, and helps in the absorption of many necessary vitamins, like vitamins 812 and K.
Since E. Coli is regularly present in human intestines and feces, the bacterium has been tracked in nature as an indicator of fecal pollution in soil and water. All enteric bacteria can ferment glucose to produce acid and gas. E. Coli, specifically, is physiologically versatile. Under anaerobic conditions it can grow by fermentation or anaerobic respiration. This allows E. Coli to adapt to both the anaerobic environment inside the intestine and external aerobic environments.