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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
The isolate possesses some enzymes required for hydrolytic reactions. Hydrolytic enzymes found to be secreted from the bacterium, are -amylase, casein, and PYRase. In the starch hydrolysis and casein tests, there was a zone of clearing around the bacterium, which was indicative of the secreted enzymes necessary to break down starch and casein. In the PYR test, the presence of PYRase was detected by a color change to red on the PYR disc after the addition of the PYR reagent (p-dimethylaminocinnamaldehyde). Hydrolytic enzymes for which the EI tested negative were urease, gelatinase, and DNAse. In the Urea Hydrolysis test, it was observed that the urea broth did not have a color change, indicating that there was no urease secreted to break down urea in the broth. Similarly, there was no gelatinase present to break down gelatin in the Gelatin Hydrolysis test, so the nutrient gelatin remained solid. It was concluded that the EI does not possess DNase because there was no clearing zone around the bacteria, indicating that DNA had not been
One bacterium was gram negative. It underwent four different tests. These tests were the EMB test (Eosin Mehylene Blue), the Sulfur Indole Motility (SIM) test, the Urease test, and the Simmon’s Citrate Utilization test. The EMB test checks for a bacteria’s ability to ferment lactose. This test is accomplished by placing the bacteria on Eosin Methylene Blue agar. The agar is selective for gram negative bacteria and those bacteria that can ferment lactose will have colored growth, usually a metallic green sheen.
Streak plate technique was used to isolate pure culture for each bacteria (2). The Gram stain was used to determine Gram reaction and morphology of each bacteria (2) Selective and differential media such as, salt agar, MacConkey agar and blood agar were used for bacterial identification (2). Gelatin deeps were inoculated to detect production of gelatinase (2). Starch Agar plate were inoculated to detect amylase (2). Ocular reticle used to determine bacteria size (2). Motility deeps were inoculated to detect motility on bacteria (2). Thioglycollate broth used to determine oxygen requirements (2). Carbohydrate fermentation
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.
Staphylococcus aureus could be eliminated because not only did the unknown bacteria grow, but it also didn’t change color to yellow. Lastly, a Catalase test was done by taking a colony from the Blood Agar plate.... ... middle of paper ... ...
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 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
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
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.
Talaro , K., & Chess, B. (2012). Foundations in microbiology. (8th ed., pp. 563-564). New York, NY:
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...
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.
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