Narrowing down the unknown microorganism to gram negative, this approach was helpful to take the next step, in some bacteria the cell wall is surrounded by cell enveloped called capsule, also some bacteria make capsule when faced in a harsh environment to protect them. A capsule stain was preform, the results were analyzed and observed. An additional procedure that was done, was the Fast Actin staining which helps to see if the bacteria contains Mycolic acid in their cell walls, which determines the structure and function of the cytoskeleton in living and fixed cells (Shah). As expected for both E.coli and K. Pnenumia the fast acting results were negative. For both E.coli and K. Pnenumia the Oxidase test was positive a reaction was obtained.
Citrate test is used to identify if an organism is capable of utilizing citrate as a sole carbon source. Citrate medium contains sodium citrate as the only carbon source. if the bacteria can utilize the citrate it will also convert to the ammonium phosphate to ammonia hydroxide. The test will conclude and the agar will turn blue it means citrate was
The slide was then rinsed and safranin was again used as a counterstain. Using oil immersion objective lens of the microscope, unknown #76 had only reddish-pink cells without any signs of spore formation. Thus the given unknown is a non-spore former. Bacillus subtilis was used for positive control and Escherichia coli for negative control for endospore
Abstract This experiment was carried out to determine the species of the unknown organism. Once a choice of the unknown was made a Gram stain was conducted to determine the gram nature and morphology of the organism which was Gram negative bacilli. Based on those results a citrate utilization test was performed resulting in a positive test. Following the flow chart the next test to conduct was a motility test which also had a positive outcome. Lastly, a glucose fermentation test was conducted to determine the unknown organism.
Introduction The purpose of this experiment was to apply all knowledge gained from the entire semester while in the lab and apply it to be able to identify an unknown genus and species gram positive bacteria. Each student was given a petri dish with an unknown Gram positive bacterium inside. The petri dish with the unknown gram positive bacteria that was used in my experiment was #8. The possible bacteria inside my petri dish could be any of the following: Bacillus subtilis, Bacillus cereus, Mycobacterium species, Corynebacterium species, Lactobacillus, Staphylococcus aureus, Micrococcus luteus, Staphylococcus epidermidis, Enterococcus faecalis, Streptococcus pyogenes, and Streptococcus pneumoniae Hypothesis I predicted that the bacteria
Since a yam is a plant of the genus Dioscorea, it contains cells that are partially permeable membranes. The membrane only allows certain molecules to pass through, water molecules are easily able to go through (Freeman 2011). Since sodium chloride is a normal saline it contains salt. The salt ions are not easily able to pass through the cell membrane like water. Compared to water, the sodium chloride should make the potatoes weigh less than in water, which should support our
It starts orange and turns yellow positive for microbe 3C Klebsiella oxytoca (Professor Brady, Personal Communication). Procedure 1 Gram stain: Purpose/ Introduction: The Gram stain reveals whether a microbe is gram positive or gram negative. It also reveals the shape and arrangement of the microbe (Professor Brady, Personal Communication). Of the forty-three possible microbes the following are gram positive: Bacillus cereus, Bacillus circulans, Bacillus coagulans, Bacillus megaterium, Bacillus subtilis,
- Little to no oxygen will result in the E. coli cells producing large quantities of acetic acid, causing the growth medium to reach pH 4 or lower however, with proper aeration the cells will be able to use many organic acids as carbon sources and the pH of the growth medium will be maintained at neutral or basic ranges. Aeration is another important factor in determining E. coli cell growth however it can continue to grow in the absence of oxygen using fermentation and anaerobic respiration. - Optimal growth temperature is 37C, cannot grow well at temperatures higher than 42C and they can tolerate lower temperatures with lower growth rate. - The doubling time or generation time for most E. coli strain in a rich medium at 37C is 20 minutes. - E. coli requires environmental sources of all of the nutrients (carbon, hydrogen, nitrogen, oxygen, phosphorus, sulphur, as well as iron, selenium, calcium, sodium and several others) in order to survive.
Major unknown #202 was given out by the instructor, and the unknown bacterium was streaked out on a Trypticase Soy Agar tube and plate to inoculating the bacterium and incubating. After incubated and grown the morphology was observed and several Gram stains were performed to determinate if the bacterium were gram positive or negative, and the morphology of the bacterium. The Gram Stain of my major unknown #202 was determinate to be Gram negative bacilli, and was double checked by the Gram check slide. Also I noticed that my bacterium was a facultative anaerobe and according to my results of endospore test, my bacterium has not endospores. So according to the list of possible major unknowns provided by the instructor, I narrow my bacterium thru