The unknown broth contains a gram negative bacterium and a gram positive bacterium. In this experiment I performed many different test dealing with things such as the presence of enzymes, fermentation abilities and different chemical reactions. I then flame the loop again and inoculated the slant. Biochemical tests were started and incubated, after the T-streak results showed no contamination or mixture of organisms, for 24 hours in a hot room of 37 degrees celcius. No issues complicated the gram negative conclusion, and the answer was Proteus vulgaris. The bacteria appeared to be a gram positive cocci. The bacteria was tested on the mannitol test and turns read mannitol to yellow.
Yielding results that showed the unknown number 25 to be a gram negative bacillus. Consultation with the Professor, confirmed the two unknown bacteria correctly as Pseudomonas aeruginosa and Staphylococcus epidermidis. Gram Positive Bacteria Bacillus subtilis Originally named Vibrio subtilis in 1835, this organism was renamed Bacillus subtilis in 1872 MicroWiki. I was nervous about working with E. The agar dishes were put in the incubator and left for 48 hours. The search began with the identification of the bacteria as being rod shaped under the light microscope.
This test is a differential that tests for sugar utilization, gas production and sulfur reduction. After a Gelatin and a Galactose test were performed, the only bacterium that remained was Pseudomonas aeruginosa. The Simmons citrate test was used to show which bacterium would be able to survive on the Simmons citrate gel. St Louis: St Louis Community College at Meramec, 2011. This positive test means that the unknown bacteria is capable of performing mixed acid fermentation. The negative result of the Gelatin test eliminated Proteus mirabilis and Pseudomonas aeruginosa as possible candidates. On day one of this process I received two bacteria, one labeled 7A and the other labeled 7B… Biochemical Unknown I.
After the broth is incubated reagent A and B are added to determine if the reduction occurred; if the broth turns red a positive reaction occurs if not zinc is added. This is a differential medium that tests an organisms ability to produce an exoenzyme called gelatinase that will hydrolyze gelatin. Gram positive did not grow. The shaped of this bacterium was rounded and ball shaped. The indicator for this test is biorhythms blue dye which will turn from green to blue if pH is at 7. The appropriate tests were prepared and applied.
Once down to two gram positive bacteria tests were completed to eliminate one more. Knowing what organism will give the student an idea of the genus and species that can cause diseases, how it can grow and reproduce including how this type of bacteria can be treated and killed, what type of antibiotic it will be susceptible to. If bacteria have the enzyme citrate-permease they can transport molecules that will be converted to pyruvate within the cell. The following results were noted: Berb 1 — Isolated colonies — growth of one color Berb 2 — Isolated colonies — growth of one color Berb 3 was determined to be the best option distinctly different colonies. The actual broth is made with urea, peptone, potassium phosphate, glucose, and phenol red. First we made sure that all the equipment was ready in front of us and all. My unknown can either be any of the following gram + bacteria ; Bacillus Cereus, Bacillus Subtilis, Stapahylococcus Aureus, Staphylococcus Epidermidis or Enterococcus faecalisMannitolTo determine bacteria that grows in high salt concentrationMannitol agarRed agar mannitol turns yellow colorUreaTo determine if bacteria can detect ureaseUrea brothNo change in color.
The Urea tube was then incubated at 37 degrees Celsius for 8 days to observe for a color change. The Vogues- Pressure test had no color change, thus indicating that the unknown was not a butadiene fermented. The unknown gram-negative bacteria is Enterobacter aerogenes. The Staphylococcus aureus and Enterococcus faecalis are positive to mannitol. This immediately ruled two of the gram positive bacteria Bacillus cerus and Bacillus subtilis. The mixture was air dried and ready for Microscopic examination.
After these experimentation my original guess was correct in saying I believed the unknown bacteria I had was E. Next I performed the Gelatins Test using a gelatin tube. In order to do the streak method, an inoculating loop was sterilized with a Bunsen burner and put into the unknown specimen. These bacteria must be able to be identified in order to treat patients properly, efficiently and safely. Coli is most commonly found in the intestines of warm blooded organisms. The Urea tests for the ability of a bacteria grown in urea broth produces urease. Under the microscope unknown number 122 showed to be blue-colored rods.
Sulfur is in the form of thiosulfate and there is also an iron-containing compound. No color change means that no sugars were fermented. The plate was labeled gram positive for future test. After three days I placed some Barrios Reagent A and Barrios Reagent B in the test tube. The Methyl Red test was carried out using the instructions provided by our lab book on page 34 2. NegativeGram - Organism does not produce enzyme casein.