Introduction The main purpose of this lab was to identify unknown bacteria, every student got different organisms. By using different types of procedures, we obtain results in order to classify the bacteria as gram positive (+) or gram (-) and from there, continue with the processes ending with the name of the bacteria. All the material including a flow chart was provided from the instructor. Methods It took about two weeks of analysis and observation in order to identify every result of each test. The first part of this process was the Gram stain in order to identify whether if the bacteria was gram positive or gram negative, the primary stain is where the Crystal violet is used since is a small molecule it enter in to the cell wall, after …show more content…
The main purpose of this test is to determine if the bacteria have the enzyme citrate. According to the Microbiology Laboratory Theory & Application, Citrate Utilization test tells the ability of an organism to use citrate as their sole carbon source to perform citrate fermentation. In this test, Simmons citrate tubes which are green, were exposed with my bacteria. After inoculation for a period of 48 hours, we obtain results if the slant change in color from green to blue or if there is growth that means that citrate is present and obviously the results are positive but, if there is no change in color and no growth this means that the result is negative and citrate is absent. In my case the tube change in color from green to blue, obtaining a positive …show more content…
The objective of this test is to determine if the bacteria produces mixed acid fermentation or acetoin. In the Microbiology Laboratory Theory & Application states that the MR test identifies organism perform a mixed acid fermentation and produce stable acid, in the other hand VP is used to identify organisms that perform 2,3 butanediol fermentation. For this test, we need a broth with our culture which is the unknown bacteria, after 48 hours of inoculation we can continue with the procedure. I transfer almost half of my broth with the bacteria carefully with a pipette to a tube ending with two tubes with culture, then for the MR I added 3 drops of methyl red reagent. On the VP, I added first 15 drops of reagent A then I added 5 drops of reagent B. If for the MR the results are immediately which means turns red immediately this means that MR is positive and VP is negative, if VP changes in about 60 minutes to red and MR stays the same this means that MR is negative and VP is positive. For my bacteria, I got MR positive since the color changed
The purpose of the Unknown White Compound Lab was to identify the unknown compound by performing several experiments. Conducting a solubility test, flame test, pH paper test, ion test, pH probe test, conductivity probe test, and synthesizing the compound will accurately identified the unknown compound. In order to narrow down the possible compounds, the solubility test was used to determine that the compound was soluble in water. Next, the flame test was used to compare the unknown compound to other known compounds such as potassium chloride, sodium chloride, and calcium carbonate. The flame test concluded that the cation in the unknown compound was potassium. Following, pH paper was used to determine the compound to be neutral and slightly
Forensic Science Introduction: Someone in a restaurant has suddenly fallen ill and a mystery powder has been discovered with the victim. As the chief investigator, your duty is to identify the mystery substance through a lab. In this lab, it will consist of five known compounds and one unknown compound. Your job is to distinguish which one out of the five substances is the mystery powder. To figure out the mystery matter you will have to compare their physical and chemical properties and match them with the appropriate compound.
What do bacteria need to grow? For bacteria to grow the most typical thing that they like ate a warm and moist environment, but that is not all that they like. Bacteria also like and environment with a PH that is normal or close to a human PH and bacteria also like an oxygen rich environment. The places that could be common to find bacteria in a building are a keyboard, a water fountain, and restrooms. A keyboard is a common place for bacteria because it is being touched constantly with hands when people type and hands are warm, so bacteria like them. The water fountain is another place that is common for bacteria to grow because people's warm hands are touching it and also it has water, which causes it to be moist. The last place that bacteria will we commonly found in buildings are restrooms. The bacteria like restrooms because many people are in then and also there is a lot of water in them.
One bacterium was gram negative. It underwent four different tests. These tests were the EMB test (Eosin Mehylene Blue), the Sulfur Indole Motility (SIM) test, the Urease test, and the Simmon’s Citrate Utilization test. The EMB test checks for a bacteria’s ability to ferment lactose. This test is accomplished by placing the bacteria on Eosin Methylene Blue agar. The agar is selective for gram negative bacteria and those bacteria that can ferment lactose will have colored growth, usually a metallic green sheen.
The purpose of this study is to identify an unknown bacterium from a mixed culture, by conducting different biochemical tests. Bacteria are an integral part of our ecosystem. They can be found anywhere and identifying them becomes crucial to understanding their characteristics and their effects on other living things, especially humans. Biochemical testing helps us identify the microorganism present with great accuracy. The tests used in this experiment are rudimentary but are fundamental starting points for tests used in medical labs and helps students attain a better understanding of how tests are conducted in a real lab setting. The first step in this process is to use gram-staining technique to narrow down the unknown bacteria into one of the two big domains; gram-negative and gram-positive. Once the gram type is identified, biochemical tests are conducted to narrow down the specific bacterial species. These biochemical tests are process of elimination that relies on the bacteria’s ability to breakdown certain kinds of food sources, their respiratory abilities and other biochemical conditions found in nature.
I also inoculated a tryptic soy broth (TSB), a nutrient gelatin deep, a motility agar deep, a fluid thioglycollate medium (FTM) tube, and a TSA plate with my unknown culture. All of these inoculated media were incubated until the next class period (about 48 hours). Then when I came to class most of my inoculated tubes and my streak plate appeared to have growth. The next step I took was making a gram stain to determine the gram reaction and cellular morphology of my unknown. I used my working slant to do this, after careful examination of the gram stain, I learned that my unknown was a gram-positive bacterium. I then preceded by making a negative stain to see the size of the cells of my unknown bacteria. The cell shape was cocci and the cells occurred in clusters of tetrads. After discovering that my unknown bacteria was gram-positive cocci, I turned to page 207 of the lab manual to narrow down my options, there was only four out of the gram-positive list that were
Bacteria play a large role in our health, the environment, and most aspects of life. They can be used in beneficial ways, such as decomposing wastes, enhancing fertilizer for crops, and breaking down of substances that our bodies cannot. However, many bacteria can also be very harmful by causing disease. Understanding how to identify bacteria has numerous applications and is incredibly important for anyone planning to enter the medical field or begin a career in research. Having the background knowledge of identifying an unknown bacteria may one day aid healthcare professionals diagnose their patient with a particular bacterial infection or help researchers determine various clinical, agricultural, and numerous other uses for bacteria.
This is because the cells are normally stained with Gram's iodine solution which forms a complex with crystal violet stain that is insoluble in water. Addition of decolourizer dehydrates the peptidoglycan layer; tightening it and shrinking peptidoglycan layer of the gram positives, making the large complex not penetrate the layer. When a counter stain is added, it does not disrupt the complex i.e. purple colouration of the Gram positive cells. Therefore, in absence of Gram's iodine solution, the Gram positive cells would stain brownish red as gram negative cells, making it difficult for the identification of the unknown bacteria (Leboffe and Pierce, 2010). 13. (2 points) Control slides are missing in The Gram Stain Investigation. What are they and what is their importance in the straining
I identified the genus and species of an unknown bacterial culture, #16, and I applied the following knowledge of morphologic, cultural and metabolic characteristics of the unknown microorganism according to the laboratory manual as well as my class notes and power point print outs. I was given an incubated agar slant labeled #16 and a rack of different tests to either examine or perform myself; the tests are as follows: Gram Stain; Nutrient Gelatin Test; Carbohydrate Fermentation; Dextrose, Lactose and Sucrose; IMVIC tests; Citrate, Indole, Mythel-Red and Vogues Proskauer test; as well as a Urease and TSI Test. Materials and Methods/Results Upon receiving the Microorganism (M.O.) #16, I prepared a slide by cleaning and drying it. Then, using a bottle of water I placed a sterile drop of water on the slide and used an inoculating loop, flame sterilized, I took a small sample of the unknown growth in my agar slant and smeared it onto the slide in a dime sized circle and then heat fixed it for ten minutes.
Solid A was identified to be sodium chloride, solid B was identified to be sucrose, and Solid C was identified to be corn starch. Within the Information Chart – Mystery White Solid Lab there are results that distinguishes itself from the other 4 experimental results within each test. Such as: the high conductivity and high melting point of sodium chloride, and the iodine reaction of corn starch. Solid A is an ionic compound due to its high melting point and high electrical conductivity (7), within the Information Chart – Mystery White Solid Lab there is only one ionic compound which is sodium chloride, with the test results of Solid A, it can be concluded that is a sodium chloride. Solid B was identified as sucrose due to its low electrical
Sordaria fimicola is a species of microscopic fungus that is an Ascomycete and are used to test for genetic variation in the lab setting (Sordaria fimicola: A Fungus used in Genetics, Volk). These organisms are what are called model organisms, or species that has been widely studied usually because it is easy to maintain and breed in a laboratory setting and has particular experimental advantages (Sordaria fimicola, Volk). S. fimicola, because it is in the Ascomycota phylum, have a distinguishing reproductive structure called the ascus, which is surrounded by the perithecium. This cylindrical sac-like structure houses 8 haploid spores; created through meiosis to produce 4 haploid spores and then mitosis to make 8 (Lab Manual, pg. 59-68). Based on the genotype they will vary in order and color. There are 3 different ratios that can arise from the 8 ascospores: 4:4, 2:2:2:2, and 2:4:2 (black/wild type and tan coloration). The 4:4 ratio suggests that no crossing over had occurred because there is no difference in order of the color parents that were mated. The two other ratios suggest genetic recombination, or crossing over, because of the
In the last decade, the number of prescriptions for antibiotics has increases. Even though, antibiotics are helpful, an excess amount of antibiotics can be dangerous. Quite often antibiotics are wrongly prescribed to cure viruses when they are meant to target bacteria. Antibiotics are a type of medicine that is prone to kill microorganisms, or bacteria. By examining the PBS documentary Hunting the Nightmare Bacteria and the article “U.S. government taps GlaxoSmithKline for New Antibiotics” by Ben Hirschler as well as a few other articles can help depict the problem that is of doctors prescribing antibiotics wrongly or excessively, which can led to becoming harmful to the body.
Bacterial cells, like plant cells, are surrounded by a cell wall. However, bacterial cell walls are made up of polysaccharide chains linked to amino acids, while plant cell walls are made up of cellulose, which contains no amino acids. Many bacteria secrete a slimy capsule around the outside of the cell wall. The capsule provides additional protection for the cell. Many of the bacteria that cause diseases in animals are surrounded by a capsule. The capsule prevents the white blood cells and antibodies from destroying the invading bacterium. Inside the capsule and the cell wall is the cell membrane. In aerobic bacteria, the reactions of cellular respiration take place on fingerlike infoldings of the cell membrane. Ribosomes are scattered throughout the cytoplasm, and the DNA is generally found in the center of the cell. Many bacilli and spirilla have flagella, which are used for locomotion in water. A few types of bacteria that lack flagella move by gliding on a surface. However, the mechanism of this gliding motion is unknown. Most bacteria are aerobic, they require free oxygen to carry on cellular respiration. Some bacteria, called facultatibe anaerobes can live in either the presence or absence of free oxygen. They obtain energy either by aerobic respiration when oxygen is present or by fermentation when oxygen is absent. Still other bacteria cannot live in the presence of oxygen. These are called obligate anaerobes. Such bacteria obtain energy only fermentation. Through fermentation, different groups of bacteria produce a wide variety of organic compounds. Besides ethyl alcohol and lactic acid, bacterial fermentation can produce acetic acid, acetone, butyl alcohol, glycol, butyric acid, propionic acid, and methane, the main component of natural gas. Most bacteria are heterotrophic bacteria are either saprophytes or parasites. Saprophytes feed on the remains of dead plants and animals, and ordinarily do not cause disease. They release digestive enzymes onto the organic matter. The enzymes breakdown the large food molecules into smaller molecules, which are absorbed by the bacterial cells. Parasites live on or in living organisms, and may cause disease. A few types of bacteria are Autotrophic, they can synthesize the organic nutrients they require from inorganic substances. Autotrophic bacteria are either photosynthetic or Chemosynthetic. The photosynthetic bacteria contain chlorophyll that are different from the plant chlorophyll. In bacterial photosynthesis, hydrogen is obtained by the splitting of compounds other than water.
There were five test solutions used in this experiment, water being the control, which were mixed with a yeast solution to cause fermentation. A 1ml pipetman was used to measure 1 ml of each of the test solutions and placed them in separated test tubes. The 1 ml pipetman was then used to take 1ml of the yeast solution, and placed 1ml of yeast into the five test tubes all containing 1 ml of the test solutions. A 1ml graduated pipette was placed separately in each of the test tubes and extracted 1ml of the solutions into it. Once the mixture was in the pipette, someone from the group placed a piece of parafilm securely on the open end of the pipette and upon completion removed the top part of the graduated pipette.