Incubate for 24 hrs at 37°C. The formation of red color after the addition of Methyl red reagent indicates the accumulation of acidic end products in the medium and is an indicative of positive test Fig 4. The strain O157:H7 releases a toxin into the body cavities that initiates an illness in mammals 2. The reason a Gram Stain was attempted was to identify the type of bacterium and determine whether or not it truly had been isolated McDonald et al. The coagulase test identifies whether an organism produces this exoenzyme.
The process of identification was achieved by utilizing procedures learnt during the semester. See probable results table below. The conclusion drawn from this is human error during the inoculating process. Upon returning and observing the streak plate, there was an abundance of green across the plate. So here is a great paper that might help you along when you are at this point in your studies.
There can be different explanations to that, either initial unknown was contaminated or some of the tests were conducted incorrectly. Purple rods were observed under a light microscope, confirming this. It inhibits cell wall synthesis mainly through inhibiting the biosynthesis of peptidoglycan. It is important for people to understand why it is beneficial for us, and even more important to understand how it is harmful. Environmental and Industrial Use of Bacillus Subtilis.
Secondly, the series of tests performed on the Gram positive unknown led to B. Starch agar is a simple nutritive medium with starch added. A third test was done in order to confirm that Escherichia coli is the unknown. For instance, if you are working in Active Directory, you can create a new user account, set up a shared folder, or change to a different domain. This tested for the hemolysis pattern of my organism. In order to identify what bacterium were present in the tube isolating techniques were performed first. A nitrate test was performed in order to detect if the bacteria was able to reduce nitrate into nitrate or some further reduced form.
This agar differentiates between the ability of organisms to ferment glucose, sucrose, or lactose and to liberate hydrogen sulfide gas from sodium thiosulfate. The bacteria was shown as rod shaped type cocci pinkish color which is a characteristic feature of a gram negative bacteria. The test tube used in this study was tube 109. Therefore, just like our instructor says about many things discussed in class: Too much of a good thing can sometimes cause more harm than good. The other plate has gram + bacteriaThe gram-negative is pinkish red with a rod shaped , cocci.
At this point everything that had been learned in microbiology lab and that had been explained in our lab manual 1 was put into action. Scientist use Bacillus subtilis in order to promote genetic research and due to its highly genetic manipulability levels, it is easier to conduct testing on Swartzburg, 2009. Incubate 24 hrs in O 2. The strong negative charge of the bacterial cell will strongly bind with the positive charged basic dyes and will impart its colour to all bacteria. Only citrate positive organisms will grow on this medium. There are numerous reasons for identifying unknown bacteria.
Materials and Methods A mixed culture of two unknown bacteria was provided by the instructor. It is commonly known as being harmful, but this is not always the case. Starch molecules are too large to enter into the bacterial cells, so some bacteria will secrete exoenzymes that will degrade starch into subunits that can be then easily utilized by the organism. This is indicated by the change in colour of the medium from orange red to deep red. So, the pre-constructed sequence of tests was still performed as if all five of the Gram positive options were still possible. Light peach to peach, No Clearing on the side of the streak. This condition can exhibit lethargy, vomiting and not being able to breathe.
The negative results explain that the bacterium did not have the enzyme urease, which breaks down urea. The results for the Urease test were positive as well and the agar c hanged from a salmon-orange to a fuch sia color. The purpose of this is to grow separately the 2 possible bacteria. This experiment was done by applying methods in order to identify an unknown bacterium. See probable results table below.
Always wash your hands after going to the bathroom, before working with food, and after coming in contact with animals. This issue could be an indication that the streak plate could have been done more carefully or that there was a contamination of sorts on the agar plate. What are the 3 types of blood agar results and how can you recognize them? You will conduct tests appropriate for your organism to determine genus and species identification. Count the number of beats in 10 seconds. With a sterilized inoculating loop the colony was separately streak , inoculated and incubated.