The dichotomous keys show process of elimination taking place and several steps that were performed to the two unknown bacteria. Bacteria number one was concluded to be either S. aureus or E. faecals. As shown, a gram stain was performed to bacteria 1, because it helped in separating the bacteria into Gram negative or positive. Bacteria 1 was Gram positive bacteria, so the next step was to eliminate the bacteria that were bacilli, because under the microscope the bacteria was shown to be cocci. Then a lactose test was performed, because it helped me in determining the bacteria metabolism (if lactose was utilized as a sugar by the bacteria) (“Phenol Red Broth”, n.d). Lastly, with the help of process of elimination a MSA test was performed to …show more content…
It was concluded that the two possible bacteria’s unknown 1 could be S. aureus or E. faecals. In order to find unknown 1 bacteria, a urease test will have to be performed, because a urease test is usually positive for some enteric bacteria’s (“Urease Test”, n.d). Therefore, S. aureus will hydrolyze urea making it positive and E. fecalis will not (“Microbiology 20 Biochemical Unknown, 2009). S. aureus is bacteria that is floral, meaning that is not harmful to people. However, “staph can cause infection on the bones, heart valves, and or bloodstream” (“Staphylococcus aureus in Healthcare Settings”, January 17, 2011). In the other hand, E. faecalis is a bacterium that can cause life threatening infection in humans. Usually in the gastrointestinal tracts, and the bacteria is “non-motile, Gram positive, Cocci bacterium” (“Enterococcus faecalis”, n.d). Similarly, to find my unknown bacteria 2, a gram stain was used to eliminate bacteria. Bacteria 2 was concluded to be Gram negative, because it was viewed pink under the microscope. Since my bacteria 2 is Gram negative, I eliminated all Gram-positive …show more content…
If the oxidase test was to be negative then the bacteria would have to be S. flexnery. S. flexneri is a bacterium that causes diarrheal disease, and it’s a “facultative anaerobe belonging to the family Enterobacteriaceae” (“Shigella flexneri”, n.d). However, if the oxidase test came as positive then the bacteria would have to either P. aeruginosa or A. faecalis (“Microbiology 20 Biochemical Unknown, 2009). Then an indole test will have to be done. An indole test is to identify if the bacteria could produce the enzyme tryptophase (SIM Medium”, n.d). If the test came as positive then unknown bacteria 2 would be P. aeruginosa (“Microbiology 20 Biochemical Unknown, 2009). P. aeruginosa is a bacterium that is the number one leading infections in humans. The bacterium is Gram negative that can lead to “endocarditis, meningitis, etc. (Friedrich.M, Dec 5, 2016). In the other hand if the bacteria came as indole negative then bacteria 2 would be A faecalis. A faecalis is a Gram-negative, rod-shape bacterium with flagella, and that belongs to the family Alcaligenaceas”, and it’s an opportunistic pathogen that induces infection (“Alcaligenes faecalis”, n.d). All in all, skills were practices to determine two unknown
I identified the genus and species of an unknown bacterial culture, #16, and I applied the following knowledge of morphologic, cultural and metabolic characteristics of the unknown microorganism according to the laboratory manual as well as my class notes and power point print outs. I was given an incubated agar slant labeled #16 and a rack of different tests to either examine or perform myself; the tests are as follows: Gram Stain; Nutrient Gelatin Test; Carbohydrate Fermentation; Dextrose, Lactose and Sucrose; IMVIC tests; Citrate, Indole, Mythel-Red and Vogues Proskauer test; as well as a Urease and TSI Test.
Each test that was used in the lab for the unknown bacteria had been performed on many different bacteria and shown that each test has different results depending on the bacteria given. The first test, the Gram stain, confirmed that the unknown bacterium was a gram negative bacilli. After performing the remainder of the tests and comparing them to the twelve negative bacteria that it could be out of it was basically a process of elimination. Basically looking at all the results and seeing which tests separated positive verses negative results the most. After reviewing all of the tests the first test that stuck out besides the gram stain was the lactose fermentation, followed by the citrate utilization test and then by the indole test. The lactose fermentation test eliminated seven of the 12 bacteria. From the five bacteria left the citrate utilization test eliminated who more of the bacteria, and last the indole test eliminated two of the three bacteria left leaving only one bacterium left. After comparing the results to the results of the 12 tests and separating which tests were positive and negative for each it was obvious that the bacteria had to be Shigella
Unknown 10b is Staphylococcus epidermidis. According to Bergey’s Manual Staphylococcus bacteria are gram positive spherical cells that occur singly, in pairs or in irregular clusters. Unknown 10b was gram positive, spherical and occurred in clusters. Bergey’s Manual also says the bacteria grow well in high salt concentrations. Unknown 10b grew well on the mannitol salt agar. The optimum growing temperature is 30-37 degrees Celsius (Bergey’s Manual). Unknown 10b grew best at 37 degrees Celsius. The lab manual and past lab results confirmed all other test results. Unknown 10b was only able to use gamma lysis, it was unable to ferment mannitol and had no coagulase activity. When comparing to past labs it is confirmed that Unknown 10b is Staphylococcus epidermidis.
In this lab project, the microbiology students were given 2 unknown bacteria in a mixed broth each broth being numbered. The goal of this project is to determine the species of bacteria in the broth. They had to separate and isolate the bacteria from the mixed broth and ran numerous tests to identify the unknown bacteria. The significance of identifying an unknown bacteria is in a clinical setting. Determining the exact bacteria in order to prescribe the right treatment for the patient. This project is significant for a microbiology students because it gives necessary skills to them for future careers relating to clinical and research work.
The purpose of this laboratory is to learn about cultural, morphological, and biochemical characteristics that are used in identifying bacterial isolates. Besides identifying the unknown culture, students also gain an understanding of the process of identification and the techniques and theory behind the process. Experiments such as gram stain, negative stain, endospore and other important tests in identifying unknown bacteria are performed. Various chemical tests were done and the results were carefully determined to identify the unknown bacteria. First session of lab started of by the selection of an unknown bacterium then inoculations of 2 tryptic soy gar (TSA) slants, 1 nutrient broth (TSB), 1 nutrient gelatin deep, 1 motility
The eighteenth exercise of the laboratory manual titled Unknown Identification and Bergey’s Manual is an experiment to identify an unknown bacterium. In this exercise, a student must randomly choose a numbered bacterium available to the class. The keys in Appendix H, located on the last pages of the book, are the major helpful tools in this exercise because it provides completed steps of tests that needs to be performed in order to distinguish certain bacteria. This means that in this exercise, various types of tests and techniques must be performed to identify the chosen unknown bacterium. The unknown bacterium that I selected was number thirty-nine in which I discovered as the Bacillus megaterium after conducting several tests.
The purpose of this project was to identify unknown bacteria species from a mixed culture. The two unknown species were initially plated onto Tryptic Soy Agar (TSA), Eosin Methylene Blue (EMB), Mannitol Salt Agar (MSA), and blood agar plates to distinguish between the two different bacteria using colony size, color, shape, and growth characteristics. By identifying and inoculating the differing types of colonies, the two unknown bacteria were purified and able to be tested
The Campylobacter species observed in 1886 from Theodor Escherich in the colonic mucus of infants who had died of “cholera infantum,” but they could not be cultured. (Miliotis & Bier 2003) Mc Fadyean and Stockman in 1909 first isolated Campylobacter fetus from aborted sheep fetuses. (Miliotis & Bier 2003) After that observed that the Campylobacter which called (Vibrio fetusovid), caused septic abortion in cattle. (Miliotis & Bier 2003) This pathogen bacterium starts to create problems dysentery in the cattle.( Miliotis & Bier 2003) In 1957 the King examined people which have bloody diarrhea the reason for the disease is the Campylobacter species. (Miliotis & Bier 2003)The species of Campylobacter are Campylobacter jejuni, Campylobacter coli, Campylobacter lari and Campylobacter fetus. (Miliotis & Bier 2003) The campyloCbacter is Gram-negative thin; (Siegrist 2014) Gram-negative bacteria are bacteria that do not retain the crystal violet dye in the Gram stain protocol. (Miliotis & Bier 2003) Gram-negative bacteria will thus appear red or pink following a Gram stain procedure due to the effects of the counter stain. (Miliotis & Bier 2003) The shape has the Campylobacter is curved and motile rod like S or spiral. (Siegrist 2014) Finally the Campylobacter has single polar flagella at one or both ends and they exhibit a rapid darting motion (Siegrist 2014), like picture1.
The objective of this lab was to identify unknown bacteria culture by using various differential tests. There are many reasons for knowing the identity of microorganisms including to find the correct antibiotic to treat infections the bacteria may have caused. All the methods and techniques used to identify unknown bacterium #79 was learned in the microbiology laboratory.
The very first step of my experiment is to get all the equipments and materials I need. What I need for this experiment are six kinds of berries I chose, enough yeasts, x-ray machine and materials for comet assay. The first step of my experiment is to give berries to the yeast. I will give berries to yeast by blending the berries using the blender, and then whiz it, so I can add the juice from the berries to the yeast. While I am doing my experiment I will have to decide how much juice I add to yeast. Then after adding the juice I will x-ray the yeast with the x-ray machine, with the help of an adult. After x-raying the yeast I will use the comet assay technique to see if it damages it or no. My final step is to collect the data.
The swab was exposed to the air when travelling to and from the location bacteria was supposed to be collected from. Hence, air-borne bacteria could have been introduced to the swab, thus, the bacteria cultivated on the petri dish for a particular quadrant could not have been solely from one location.
The purpose of the study was to identify what are unknown bacteria by applying all the methods that we have learn in microbiology for the identification of are unknown. We apply the different test and be able to recognize the different characteristic of are unknown. Each test has its own purpose to help identify the bacteria by the reaction.
The purpose of the microbiological experiment was to applying different types of techniques and methods learned in microbiology lab to a bacteria so that it may be accurately and precisely identified. “The words accurately and precisely are not the same in microbiology, accurately has the meaning of if repeated the same answer continues to be the result, precisely has the meaning of the correct answer.” “Microbiological experimentation often involves test that determine the ability of an organism to use or produce some chemical, or to determine the presents or absence of a specific organism in a sample.” The scientific methods that were performed aided in the precise identity of the bacteria.
In the Hemolytic Activity Test, the 26A bacteria was beta hemolytic but I also could have stab the