Preview

Unknown Bacteria Lab Report

Good Essays
Open Document
Open Document
629 Words
Grammar
Grammar
Plagiarism
Plagiarism
Writing
Writing
Score
Score
Unknown Bacteria Lab Report
Unknown Bacterium #22

Purpose
The purpose of this experiment was to find the identity two unknown bacteria in the given test tube. Materials •Bacterial Loop •Bunsen Burner • Petri Dish with agar •Crystal Violet •Gram’s Iodine •95% Ethanol

•Safrin •Glass Slides

•Microscope •Unknown bacteria in test tube

Procedure

On the first day, one plate was streaked qualitatively and left it in the 25 degrees celsius incubator over five days and attempted to gram stain from the test tube. On the second day, took out my plate from the incubator and examined the plate for bacteria. Then, three more plates where streaked qualitatively and placed
…show more content…
This was compleated by growing the bacteria on a petri dish with agar, gram staining, then examning under a microscope. The bacteria identified was M. Roseus and B. Megaterium. The identity of these bacteria was mostly determined by the positve gram stain results and the shape they where under the microscope. Both of these bacteria where identified as gram positive (as shown in the table previously). This was determined beause of the nonexistant fatty layer in the cell’s cell wall that trapped the purple crystal violate. The second big thing that identified these bacteria was the shape you could see under the microscope. While looking under the oil immersion lense, the B. Megaterium was shaped as a rod, and the M. Roseus was shaped as a circle. The diference between these two was, the rod was a much longer and skinnier shape compared to the circle whitch was smaller and more round than the rod was. The error in this experiment was that during gramstaining the second bacteria. I was able to identify three different bacteria. One was small purple circles (the M. Roseus), another was purple rods (B. Megaterium), and the last one was small pink circles that was not identified. In this lab, one of the problems that was encountered was the bacterias would not grow. Although this was probably because failing to cool the loop while streakig, this was still one one of the main problems encountered. Another issue that was

You May Also Find These Documents Helpful

  • Good Essays

    A: In wet mount stain, color of the slide is same gray, colorless and glossy. Liquid or fluid appearance is visible. Bacteria and background don’t have a much of difference in color. Although, bacteria are defined and visible noted. Most of the time they are single round cells. In direct stain with crystal violet, again background is colorless and glossy. Bacteria is blue and some uneven grouping is noted. In this example the dye methylene blue stain is used. In indirect stain with Congo red stain, background is again colorless and glossy. Bacteria are orange to red and fine defined. At smaller magnified example they are grouping in uneven clusters, but in highest magnifier we can see single bacteria dark cell.…

    • 472 Words
    • 2 Pages
    Good Essays
  • Satisfactory Essays

    Each student was given an unknown bacteria to figure out. I was given the unknown bacteria S38. Everybody is supposed to do all sorts of test to identify the bacteria. The first thing I did was smear my bacteria on a liquid medium. I then proceeded to incubate the medium for 24-48 hours.…

    • 334 Words
    • 2 Pages
    Satisfactory Essays
  • Best Essays

    Enteric bacteria are members of the Enterobacteriaceae family of microorganisms. These gram negative, rod shaped, facultative anaerobes are found in the intestinal tracts of humans and animals. Enteric bacteria can be pathogenic; however, they are also a normal part of human bacterial flora and are therefore found in both healthy and infected hosts. This is why fecal matter found in contaminated water and food supplies as well as public recreational areas such as beaches can cause serious intestinal tract infections and urinary tract infections, among other diseases (Todar 2012). Escherichia coli is a major…

    • 1367 Words
    • 6 Pages
    Best Essays
  • Powerful Essays

    The purpose of this experiment was to use a systematic battery of tube tests and plates designed to lead to identification of two unknown bacterial species, from the combination of all results. A sample of bacteria was used, labeled “Sample 4”, from which both species was to be obtained, one gram positive and one gram negative. Table 1 is a list of the possible bacteria to be identified; the basic ideas and practice of identification of an unknown sample of bacteria are important for a microbiologist to develop. Not only is proper procedural practice necessary, the investigator must use critical thinking to solve the…

    • 2799 Words
    • 12 Pages
    Powerful Essays
  • Good Essays

    Cocci Bacteria Lab Report

    • 669 Words
    • 3 Pages

    In this procedure we used crystal violet, the primary stain to dye the bacteria purple, gram’s iodine, which will cause the crystal violet color to bind more tightly with the cell, ethanol, which removes the purple color from gram-negative bacteria, and then safranin, a pink dye, (Caldas, Herron, La Mota-Peynado, Wong, and Trowbridge, 2017). After heat fixing a slide with a smear of a bacterium species, we wash the slide first with crystal violet and let it sit for one minute and rinsed will distilled water. We repeated this same procedure with gram’s iodine. Before we add the safranin however, ethanol, is applied and only sitting on the smear for about 20 seconds. Next safranin is applied and goes through the same producer as before. Gram positive bacteria have a thick peptidoglycan layer cell wall which holds the purple dye of crystal violet even after the ethanol is applied. While gram negative bacteria is changed pink after it is decolorized with ethanol and recolored with safranin. This is the distinguishing factor between gram positive and gram…

    • 669 Words
    • 3 Pages
    Good Essays
  • Good Essays

    I would not say science is storybook fun, but who knew it become a mystery. Trying to find out what was in our number seven vial would become a battle we were willing to take on. As I began the test of deciding if our little bacteria friend was gram positive or negative, Jordan my science teammate, was putting together a smear plate. In as little as ten minutes we had discovered by the pink oval shapes we were observing, our microbe friend was a gram negative rod. We had narrowed our search down to five! We decided next we would do oxygen along with a motility test. Along with those, we did a fermentation investigation. These tests would narrow our pursuit down even further. Unfortunately these tests take time.…

    • 802 Words
    • 4 Pages
    Good Essays
  • Better Essays

    The method used in this experiment was derived from Cappucino and Sherman (2011) as detailed in experiment 10 with substitutions for the unknown bacteria. Aseptic lab technique was followed. One slide of the #7 unknown bacteria and one slide which included both unknown #7 and unknown #2 were prepared using the following stain technique.…

    • 1272 Words
    • 6 Pages
    Better Essays
  • Powerful Essays

    Then we performed a KOH string test to see if our unknown bacterium is Gram-positive or Gram-negative. We added a drop of 3% KOH (potassium hydroxide) to the leftover of our colony that we chose earlier to see if the mixture becomes viscous and forms a string. We recorded our observation and moved on to incubating our live culture on the EMB-lactose and PEA. Vancomycin wasn’t available to be used. We added our live culture to the EMB-lactose and PEA and added sterile beads to spread the bacterial cells all over the surfaces of the two agars and removed the beads and incubated the two agars. While the agars were incubating, we prepared our gel and loaded our respectful samples and ran the gel. After the gel finished running, we got a picture of our gel and recorded our observation for later…

    • 2044 Words
    • 9 Pages
    Powerful Essays
  • Good Essays

    An experiment such as this one serves the purpose of allowing us, the students, to apply what we already know about any organism and any laboratory procedure to the difficult task at hand. It is possible to identify a mixed culture by running familiar experiments on the unknown bacteria and taking information already known about specific bacteria and applying it to the results. This helps to slowly eliminate any bacteria that do not correspond with the results. I obtained tube number twelve to run various tests on. There are only two microorganisms, one is Gram positive and one is Gram negative, inside the test tube. The Gram positive possibilities are to be narrowed down from Bacillus cereus, Clostridium perfringens, Corynebacterium xerosis, Enterococcus faecalis, Streptococcus agalactaie, Staphylococcus aureus, and…

    • 1348 Words
    • 6 Pages
    Good Essays
  • Better Essays

    Bacillus Badius

    • 1222 Words
    • 5 Pages

    In this experiment I am attempting to identify an unknown microorganism. It is important to identify an unknown microorganism for many reasons, such as, if doctors need to treat an infection they need to first identify the bacteria that is causing the infection in order to know how to kill it. Unknown bacteria may also have clinical uses. For example, Penicillin, which is sometimes used to treat ear infections, is actually isolated from a fungus (Types of antibiotics). Microorganisms are classified based on many characteristics and different microorganisms may share several of these characteristics. Thus, making the possibility of identifying the microorganism, using a single test, none. Over a three week time span I was able to successfully identify the organism Bacillus badius by combining the results of several tests. For majority of the procedures I utilized the aseptic technique which consists of sanitary measures, such as, washing your hands. I used the Gram Stain test to determine the organisms’…

    • 1222 Words
    • 5 Pages
    Better Essays
  • Good Essays

    Because of their small size, rapid rate of reproduction, and relatively simple structure, bacteria are excellent subjects for laboratory studies. This investigation will introduce you to techniques of microbiology that will be of use to you throughout your biological work.…

    • 1405 Words
    • 6 Pages
    Good Essays
  • Good Essays

    Isolation of Bacteria

    • 811 Words
    • 4 Pages

    The purpose of the lab is to apply what has been learned so far in Microbiology, and use it to collect and examine microbial species from the physical environment. The physical environment around the lab will be utilized to find out the variety of different microbial species growing in and around the lab. This investigation will help in preparation for the individual projects that will be done at the end of the semester.…

    • 811 Words
    • 4 Pages
    Good Essays
  • Good Essays

    Gram staining lab report

    • 487 Words
    • 2 Pages

    Gram staining is a very important technique used in biology labs all over the world. It is a technique used to differentiate types of bacteria using certain physical and chemical characteristics of their cell walls. Gram positive bacteria (which show up purple after the gram staining process) have a very thick layer of peptidoglycan where gram negative bacteria (which show up pink after the gram staining process) have a much thinner layer of peptidoglycan. One thing to note is that not all bacteria are gram positive or gram negative, some are non-reactive to this type of staining. Bacteria that are non-responsive to this technique are known as gram insensitive.…

    • 487 Words
    • 2 Pages
    Good Essays
  • Satisfactory Essays

    lap report

    • 386 Words
    • 2 Pages

    The unknown bacterium tube number 12 was picked. According to the procedures that we have been learned in class, our performances were running properly. More than 20 kinds of experiments were performed to identify unknown bacterium.…

    • 386 Words
    • 2 Pages
    Satisfactory Essays
  • Good Essays

    Guava Leaves Case Study

    • 854 Words
    • 4 Pages

    For the bacteria’s case, using a sterile borer, 5 mm diameter wells are mixed into the medium. The samples are inoculated with the test bacterium which needs to be adjusted to the 0.5 McFarland standard solution; a sterile cotton swab was dipped into the suspension, rotated several times, and pressed firmly on the inside wall of the tube above the fluid level removing excess inoculum. The surface of the agar plate was streaked over the entire sterile agar surface rotating the plate to ensure an even distribution of inoculum with a final swab around the rim. The plates need to dry for 3-5 min. Fifty uL aliquots of each test extract are dispensed into each well after the inoculation of the plates with bacteria. The wells are arranged 2 inches apart in a triangular form. Three plates are used for the extracting of bacterium and the same extract is used for each plate. For each bacterial strain, controls are maintained where pure solvents are used instead of the extract. The plates are sealed with parafilm, labeled, and placed in an incubator set to 37°C. After 24 hours of incubation, each plate should be examined for inhibition zones by using a ruler in millimeters (Biswas & et al,…

    • 854 Words
    • 4 Pages
    Good Essays