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Identification of unknown bacteria microbiology
Identification of unknown bacteria microbiology
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Recommended: Identification of unknown bacteria microbiology
Introduction
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.
Test Result
Unknown# 79 was grown on TSA slant in a 370 c temperature after two days, the microbe replicated to more than 100 microorganisms, which has cream pigments, and convex elevations. The microbe entire margins and convex elevations. The microbe appears to be circular and abut 0.4-0.7 micro meter in diameter. Crystal violet, iodine, alcohol and safranin were used to determine the gram stain of unknown #79 as a gram positive bacteria. Under a microscope with 100x oil lens, the microbe was viewed as a coccus shaped and formed clusters. The bacteria motility was detected by growing the bacteria in a special kind of nutrient agar, the test was done in a tube deep containing motility medium. We stab it with an inoculation needle in a straight line down the center of the deep and the bacteria grows only along the inoculation line which shows that the bacterium is non-motile. Thioglycollate broth is multipurpose, enriched, differential medium used primarily to determine the oxygen requirements of microorganisms. In this test the growth was everywhere but it was best at the top therefore this determined the unknown #79 to be facultative anaerobe.Fermentation test is performed to detect the ability of microorganisms to ferment a specific carbohydrate. Based on the fermentation testes the microbe did ferment Glucose, Sucrose, lactose and Maltose. Si...
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...ll biochemical tests performed came out as expected except for the starch and urea digestion. On the first test starch shows a false + test and then on the second test it comes as a negative result. The same thing happened with the urea digestion it showed a false + test on the second test as a negative result, matching the result of a known bacterium, staphylococcus aureus.Therefore, it was concluded that unknown #79 was staphylococcus aureus.
References
Community college of Denver (2014).Introduction to microbiology laboratory manual.Boston,MA;person Learning solution
Oxidative/fermentation glucose test. (2014, April 15). Retrieved 04 23, 2014, from Wikipedia: http://en.wikipedia.org/wiki/Oxidative/fermentation_glucose_test
Gelatin Hydrolysis Test. (n.d.). Retrieved 4 22, 2014, from http://www.vumicro.com/vumie/help/VUMICRO/Gelatin_Hydrolysis_Test.htm
Upon receiving the unknown Microorganism (M.O.) #16, I prepared a slide by cleaning and drying it. Then, using a bottle of water I placed sterile drop of water on the slide and used an inoculating loop, flame sterilized, I took a small sample of the unknown growth in my agar slant and smeared it onto the slide in a dime sized circle and then heat fixed it for ten minutes. After ten minutes had passed, I collected the ingredients needed to perform a gram stain. I got the primary stain, crystal violet, and flooded my smear for sixty seconds, and then rinsed the color off with water until the water ran clear. I then flooded the smear with the mordant, grams iodine, and let that sit on the slide for sixty seconds as well. I then rinsed the grams iodine off with water and applied alcohol to the smear to decolorize the cells; however I made sure not to over decolorize and only put enough drops on the smear till the purple ran clear. I then rinsed the slide with water and flooded the smear with safranin the counter stain and let it sit for sixty seconds and then rinsed the color off with water. I blo...
The unknown bacterium that was handed out by the professor labeled “E19” was an irregular and raised shaped bacteria with a smooth texture and it had a white creamy color. The slant growth pattern was filiform and there was a turbid growth in the broth. After all the tests were complete and the results were compared the unknown bacterium was defined as Shigella sonnei. The results that narrowed it down the most were the gram stain, the lactose fermentation test, the citrate utilization test and the indole test. The results for each of the tests performed are listed in Table 1.1 below.
Table 6 shows the results of the biochemical tests. The isolate can obtain its energy by means of aerobic respiration but not fermentation. In the Oxidation-Fermentation test, a yellow color change was produced only under both aerobic conditions, indicating that the EI can oxidize glucose to produce acidic products. In addition to glucose, the EI can also utilize lactose and sucrose, and this deduction is based on the fact that the color of the test medium broth changed to yellow in all three Phenol Red Broth tests. These results are further supported by the results of the Triple Sugar Iron Agar test. Although the EI does perform fermentation of these three carbohydrates, it appears that this bacterium cannot perform mixed acid fermentation nor 2,3-butanediol fermentation due to the lack of color change in Methyl Red and Vogues-Proskauer
After 5 days of growth each slant was tested using the gram staining technique to confirm the complete isolation of the bacteria. Both isolations were completely successful. Then each sample of bacteria was subjected to a series of tests for identification.
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 study is to identify an unknown bacterium from a mixed culture, by conducting different biochemical tests. Bacteria are an integral part of our ecosystem. 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. These biochemical tests are process of elimination that relies on the bacteria’s ability to breakdown certain kinds of food sources, their respiratory abilities and other biochemical conditions found in nature.
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.
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 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 first step to the unknown is selecting an actual organism. The best way to select a culture is based on a high-quality distribution. Equally important, shaking up the broth tube facilitates in the distribution. Upon selection, a gram check for purity is performed. Step by step instructions for this procedure can be found in Benson’s, Microbiological Applications p. 99. Furthermore, an aseptic technique must be performed for this test and the entire tests following the unknown. The purpose of this test is to differentiate between gram positive and gram-negative bacteria. The key indicator of gram-positive bacteria is a purple stain and a pink stain for gram-negative bacteria. A slide is viewed with a microscope under oil immersion. Equally
There was a huge crisis in Little Rock, Arkansas well according to Arkansas Governor Orval Faubus. The huge crisis was nine African Americans tried to attend a formerly all white school. These nine African American students were now and forever more known as The Little Rock Nine. The nine student names were Minniejean Brown, Elizabeth Eckford, Earnest Green, Thelma Mothershed, Melba Pattillo, Gloria Ray, Terrance Roberts, Jefferson Thomas, and Carlotta Walls. When the African American students tried to enter the school they were stopped by the Arkansas National Guard.
In 1954, the Supreme Court took a step in history with the Brown V. Board of Education of Topeka by stating that, “In the field of public education the doctrine of ‘separate but equal’, has no place. Separate facilities are inheritably unequal.” Little Rock, Arkansas a city in the upper south became a location of a controversial attempt to put the court order into effect when nine African American students were chosen to desegregate Central High in Little Rock. How did the Little Rock Nine affect America? Sanford Wexler stated in The Civil Rights Movement: An Eyewitness History,” its “effect would ripple across the nation and influence the growing Civil Rights Movement;” in addition, the Little Rock crisis forced the federal government to come down on state government in order to protect the rights of African Americans.
Little Rock, Arkansas is going to be remembered forever. This remembrance is all dedicated to nine African American students taking a stand in order to have an education at Little Rock Central High School. In 1957, the first group of African Americans, the little rock nine, were forced to stand outside of Little Rock Central High School and prohibited to try to enter. Governor Orval Faubus of Arkansas had sent the state to forbid them from going in. The Little Rock Nine was consisted of Ernest Green, Elizabeth Eckford, Jefferson Thomas, Terrence Roberts, Carlotta Walls LaNier, Minnijean Brown, Gloria Ray Karlmark, Thelma Mothershed, and Melba Pattillo. Out of the nine students students Ernest Green was the first African American to graduate Little Rock Central High School. All of the other students dropped out either because of personal issues or they just cracked under pressure because of all the racism and humiliation. ( “Beyond Racism: Little Rock Nine Member and Civil Rights “). Throughout the beginning school year of 1957 “The Little Rock Nine “was still not aloud to enter school under the command of Governor Faubus of Arkansas. It wasn’t until the end of September 1957 that the Little Rock Nine was aloud to enter the school.
I found something in the sample that even my teacher could not identify, and from then on I had fallen in love with microbiology. My interest in
stains on sputum’s and body fluids, and have completed a few AFB cultures. Apart from