In the Hemolytic Activity Test, the 26A bacteria was beta hemolytic but I also could have stab the bacteria to see if it was classified as aerotolerant. The S. epidermidis broke down the red blood cell, leaving a ring around the bacteria, due to an enzyme streptolysin. During the catalase test, the bacteria created bubbles meaning oxygen was released conclusioning that it can break down hydrogen peroxide into water and oxygen making it facultative anaerobic. As for the bile test, the bacteria turned black, proving that the bacteria was able to break down esculin. I originally want to test the bacteria on a DNase plate to see if it could hydrolysis DNA, but since the lab ran out of plates I wasn’t able to. As for the
Tellurite-Glycine Agar Test,
Data table 1 Well plate Contents Glucose concentration A 3 drops 5% sucrose + 3 drops distilled water Negative B 3 drops milk+3 drops distilled water Negative C 3 drops 5% sucrose +3 drops lactase Negative D 3 drops milk +3 drops lactase 15+ E 3 drops 20% glucose +3 drops distilled water 110 ++ Questions B. In this exercise, five reactions were performed. Of those reactions, two were negative controls and one was a positive control.
Digestion of the haemolytic and non-haemolytic cells allowed for easier identification of fragments during electrophoresis analysis. Lane 12 in figure 3 show the size markers of SPP1 digested with EcoR1 while lanes 6 and 7 show samples of pK184hlyA and pBluescript digested with EcoR1 and Pst1. Lane 4 was loaded with plasmid DNA from haemolytic cells digested with EcoR1 and Pst1 while lane 5 was loaded with EcoR1 and Pst1 digested DNA from non-haemolytic cells. There was a lack of technical success in both lanes due to no bands appearing in lane 4 and only a single band appearing in lane 5. Theoretically, two bands should appear in both lanes after successful to allow for fragment identification. A possible explanation for the single, large fragment in lane 5 is that successful digestion did not take place and the plasmid was only cut at one restriction site leaving a large linear fragment of plasmid DNA. The absence of bands in lane 4 could be because there was not enough plasmid loaded into the lane. Another possibility could be that low plasmid yield as obtained when eluting the experimental samples in order to purify it. Lanes 8 and 9 belonged to another group and show technical success as two bands were present in both the haemolytic (lane 8) and non-haemolytic (lane 9) lanes. If the
The isolate possesses some enzymes required for hydrolytic reactions. Hydrolytic enzymes found to be secreted from the bacterium, are -amylase, casein, and PYRase. In the starch hydrolysis and casein tests, there was a zone of clearing around the bacterium, which was indicative of the secreted enzymes necessary to break down starch and casein. In the PYR test, the presence of PYRase was detected by a color change to red on the PYR disc after the addition of the PYR reagent (p-dimethylaminocinnamaldehyde). Hydrolytic enzymes for which the EI tested negative were urease, gelatinase, and DNAse. In the Urea Hydrolysis test, it was observed that the urea broth did not have a color change, indicating that there was no urease secreted to break down urea in the broth. Similarly, there was no gelatinase present to break down gelatin in the Gelatin Hydrolysis test, so the nutrient gelatin remained solid. It was concluded that the EI does not possess DNase because there was no clearing zone around the bacteria, indicating that DNA had not been
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.
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.
After the end of the experiment the unknown 10 sample was Staphylococcus epidermidis. Came to this conclusion by first beginning with a Gram Stain test. By doing this test it would be easier to determine which route to take on the man made flow chart. Gram positive and gram negative bacteria have a set of different tests to help determine the unknown bacterium. Based on the different tests that were conducted in lab during the semester it was determined that the blood agar, MSA, and catalase test are used for gram positive bacteria while Macconkey, EMB, TSI, and citrate tests are used for gram negative bacteria. The results of the gram stain test were cocci and purple. This indicated that the unknown bacteria were gram positive. The gram stain test eliminated Escherichia coli, Klebsiella pneumonia, Salmonella enterica, and Yersinia enterocolitica as choices because these bacteria are gram negative. Next a Blood Agar plate was used because in order to do a MSA or a Catalase test there needs to be a colony of the bacteria. The result of the Blood Agar plate was nonhemolytic. This indicated that there was no lysis of red blood cells. By looking at the plate there was no change in the medium. Next an MSA test was done and the results showed that there was growth but no color change. This illustrates that the unkown bacteria could tolerate high salt concentration but not ferment mannitol. The MSA plate eliminated Streptococcus pneumonia and Streptococcus pyogenes as choices since the bacteria can’t grow in high salt concentration. Staphylococcus aureus could be eliminated because not only did the unknown bacteria grow but also it didn’t change color to yellow. Lastly a Catalase test was done by taking a colony from the Blood Agar plate...
One of the most primitive actions known is the consumption of lactose, (milk), from the mother after birth. Mammals have an innate predisposition towards this consumption, as it is their main source of energy. Most mammals lose the ability to digest lactose shortly after their birth. The ability to digest lactose is determined by the presence of an enzyme called lactase, which is found in the lining of the small intestine. An enzyme is a small molecule or group of molecules that act as a catalyst (catalyst being defined as a molecule that binds to the original reactant and lowers the amount of energy needed to break apart the original molecule to obtain energy) in breaking apart the lactose molecule. In mammals, the lactase enzyme is present
I began my test to classify my unknown bacteria by performing the Gram staining because according to the first period procedure of the laboratory manual and the Appending H, it was the first test that should be done to plan and proceed to the next tests. Washed bottle of distilled water, three slides, and Gram-staining reagents
Upon completion of the experiment we were able to examine the DNA. First, the electrophorese
At the given time sets, CTAB was added to the tubes to kill the E. coli cells and lyse the cells to release its contents including galactosidase enzyme.
mutans was problematic due to its difference with Bergey’s Manual result for the catalase test. However, after comparing it with a peers results, it seems very possible that the strain we are working with varies from the strain used in Bergey’s. Bacteria possess the ability to develop varying phenotypes within the same species due to frequent mutation and horizontal gene transfer. Therefore, it is possible that the results obtained in our lab may vary from those provided in Bergey’s Manual. Arriving to the conclusion that the Gram negative bacteria was Klebsiella pneumoniae was much more direct. Using Bergey’s Flowchart for identification, the bacteria shared the test results and had a similar shape and
Coli. Each culture was grown in an M9 medium. One culture utilized glucose as a carbon source, while the other utilized succinate as a carbon source. Two other treatments of E. Coli were also tested, one without succinate and one without glucose. These two treatments were added as a baseline to compare how much succinate and how much glucose actually helped the E. coli grow. The two treatments were covered with parafilm and for the purposes of this experiment, will be called blanks. These cultures remained within their assigned group all day to measure the growth of E. Coli. The following process was repeated by all groups throughout the day. A cuvette was labeled with the sample that was being tested. The writing was at the top of the cuvette to prevent light from being disturbed and affecting results. 3 mL of the tested sample were placed in a flask using a sterilized 1 mL pipet. The spectrophotometer was then rezeroed with the corresponding blank inside. This was so that only growth would be measured. After recording measurements the flasks were returned to the incubator and the pipets were disposed of in a red biohazard bag. The contents of the cuvette were poured into 50% bleach to kill any E. coli. The cuvette was rinsed with distilled water. This process was repeated every 30 minutes over the course of eight and a half hours. Measurements at 12:00, 12:30, and 15:30 were missed due
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.
Figure 1 is an illustration of lab 1, the serial dilution performed for bacteria. This table is describing the number of colony forming units and the observations of the plates per dilution after a week. We didn’t stain the bacteria because time was limited and we would have only determined if they were gram positive or negative.
stains on sputum’s and body fluids, and have completed a few AFB cultures. Apart from