Micro Unknown Lab Report Essay Example

Micro Unknown Lab Report Paper The rationale of performing these tests was to distinguish six different microbes room one another and to compare how their metabolic and biochemical processes differ from species to species to determine the unknown sample. The tests included: Triple sugar iron agar (TSAR), the Sulfide Indolent Mobility (SIMI) test, Glucose fermentation, the Methyl Red test, the Vogues-Prosperous test, Citrate test, the Areas Test, and finally the Gelatin test. The microbes that were tested during this lab were: Escherichia coli, Entertainer arrogates, Kielbasa pneumonia, Protest miracles, Pseudopodia organisms, and Salmonella typographic. The sample labeled #11 could have been any of the six microbes. A gram stain was performed to assess the shape and other characteristics of the bacteria, and to ensure that there was no gram positive contamination. Gram positive cells have a thick outer pedagogical layer that traps the crystal violet-iodine complex more than gram negative cells. As a result, they are less vulnerable to the De-colonization step with alcohol making them appear purple in color, while the gram bacteria negative appear pink. Triple sugar iron agar slant tests for multiple things: sugar fermentation of glucose, lactose, and sucrose, and the production carbon dioxide and hydrogen sulfide. The gases are easy to identify. If any carbon dioxide is produced cracks or bubbles appear inside of the medium, and sometimes enough CO is produced to push the slant up towards the top, this will be reported as +g. We will write a custom essay sample on Micro Unknown Lab Report specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on Micro Unknown Lab Report specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on Micro Unknown Lab Report specifically for you FOR ONLY $16.38 $13.9/page Hire Writer The HAS is identified by how the gas reacts with an iron compound and makes the agar turn black. There are two possible types of sugar reactions that take place in the areas of the butt and the slant of the medium. The outcome of sugar metabolism will be acid production, so the pH indicator phenol red will turn yellow, and be reported as A. If there is no sugar diabolism, or alkaline by-products are made, will cause the indicator to stay the same color red, and reported as a K. THIS medium is prepared as a shallow agar with a deep butt, providing for both an aerobic and anaerobic environment. A THIS medium must be checked within about 12 hours to see if it ferments glucose, and again after 24 hours to see if it ferments lactose and sucrose. If the slant returns to being red and the butt is still yellow after this time period, the organism ferments glucose but not the other sugars. If it is completely yellow after the time interval, this indicates that the organism ferments all here sugars. SIMI Medium is used as differential test of microorganisms on the basis of hydrogen sulfide production, indolent production, and motility. The Sulfur reduction test is useful in differentiating enteric organisms, the Indolent test is used for differentiating the Interchangeable, and the Motility test is useful for testing a wide variety of organisms (condonable. Com). Casein is rich in thyrotrophic which is reduced and produces indolent by the enzyme transparency. Ferric ammonium sulfate is the indicator for HAS production. Once the medium was done incubating Kvass reagent was added to the tube. If the sample was positive the reagent would have a color change to red, if the reagent remained clear, a negative result was reported. Glucose fermentation uses Phenol Red Broth as differential test medium typically used to differentiate based on the color change of the pH indicator. Phenol red turns yellow below a pH of 6. 8, pink above a pH of 7. 4, and remains red in between. A Durham tube is used to collect any gas that may be produced, and is reported as (+g) if a bubble appears on the inside and (-) if the organism cannot ferment the glucose and no bubble is trapped inside the tube. If the broth turns yellow, it means that acid was produced and reported as A. If the organism can break down the amino acids be De-animation and ammonia is produced, this will raise the pH level turning it pink. This alkaline result was reported as K. The Methyl Red test is a differential test for bacterial respiration used to differentiate strains of chloroform bacteria capable of performing mixed acid fermentation that will lower the pH despite the phosphate buffer (http://faculty. Deanna. FDA. Due). Mixed acid fermentation is confirmed by using methyl red as an indicator. It is red ant pH 4. And below, allow at pH 6. 2 and above, and orange in between. Red is a positive result reported as (+), yellow is a negative result reported as and orange is negative or inconclusive. The Vogues-Prosperous test to detect organisms that are able to ferment glucose, but convert the products to action and 2,3-butadiene. This is deduced by the addition of Reagent A and Reagent B, and the observation of the color change thereafter. Reagent A is a solution of -naphtha and alc ohol. Reagent A catalysts the conversion of action to dedicate. Dedicate teens react with guanidine-containing compounds from the potent to form a red color in he presence of -naphtha. Reagent B is a solution of potassium hydroxide and water. It absorbs CO in the medium and acts as an oxidation agent, cataloging the reaction that converts action to dedicate (Dalton. Com). After the UP reagents have been added, a red color is observed, this is a positive result reported as if a copper color develops, the result is negative and reported as Citrate test uses Simmons citrate agar to see if the organism is able to utilize citrate as a carbon source. Only bacteria that possess the enzyme citrate-permeate can transport citrate inside the cell so it can be converted into private. Simmons citrate agar utilizes sodium citrate as its only carbon source and ammonium phosphate as the nitrogen source. The pH indicator biorhythms blue dye is green at a pH of 6. 9 and blue at pH of 7. 6. Bacteria that can survive on the agar and utilize the citrate, alkaline the agar by breaking down the ammonium phosphate to ammonia and ammonium hydroxide, both increase the PH. Any change to a blue color is a positive result reported as (+), and if there is no change and the agar remains green the result is negative and reported as (-). The Urea hydrolysis is catcalled by the enzyme areas. Areas catalysts the hydrolysis of urea into carbon dioxide and ammonia using water. A urea broth is used that contains yeast extract as its only nutrient source, buffers to inhibit localization of the medium, and phenol red as a pH indicator. Phenol red in this solution will be yellow or orange bellow pH 8. And pink above, to show any increase in PH. A pink color in the both indicates a positive result and reported as and an orange or yellow appearance the result is negative and reported as G). The Gelatin test is used to see if the microbe produces the enzyme gelatins. Gelatin is a protein made from collagen, made from animal connective tissue. Gelatins is an extracurricular proteolysis enzyme that aids in the breakdown of protein into amino acids (Harsh 244). Gelatin is used as the medium, which can liquid at room temperature but solidifies at about ICC. Since the gelatins enzyme can be quite slow, an incubation time o one week is needed. A positive test result will be reported if the sample remains a liquid after it is placed in the cold room, and a negative result will be reported if it re-solidifies. Experimental Proceed rest: The tests performed provided key information about the unknown bacteria and how it carries out its metabolic functions. The visualization of bacteria at the microscopic level is made possible by the use of various stains, which react with elements present in some cells but not others. The Gram stain was utilized in this procedure in four essential steps: apply the primary stain crystal violet, fix with iodine, decolonize with 95% ethyl alcohol to wash out the crystal violet-iodine complex, and the counter-stain Safaris was added. THIS medium was inoculated using an inoculating needle by stabbing the agar through the butt, and then the addle was pulled out and a streak was made up the slant. The THIS medium was incubated at ICC and checked after 18 and 24 hours for a change in color. ITS contains the three carbohydrates glucose, sucrose, and lactose. The medium also contains animal and yeast extract, and peptides as the sources of nitrogen, vitamins and minerals, and ferrous ammonium sulfate as the indicator for HAS. Phenol red is the pH indicator. (macromolecular. Org) The SIMI medium contains casein digest and animal digest to provide peptides to provide nutrients, vitamins, and minerals that are essential for growth. The SIMI medium was inoculated by stabbing the medium with an inoculating needle, and incubated at ICC for 24 to 48 hours. Once the medium was done incubating Kvass reagent was added to the tube to check for indolent production. Phenol Red Broth, used for glucose fermentation, contains potent, phenol red (a pH indicator), a Durham tube, and glucose. The broth is inoculated with the inoculating loop, and incubated at ICC for 48 hours. The Methyl Red broth contains potent, glucose, and a phosphate buffer. The broth is inoculated with the inoculating loop, and incubated at ICC for 48 hours. Once the sample is done incubating, a 1. 0 ml aliquot is taken and three drops of the Methyl red indicator is added. The results of a red color can be observed immediately if it is positive, otherwise it is a negative result. The Vogues-Prosperous broth contains potent, glucose, and a phosphate buffer just as in the MR.. Broth. The broth is inoculated with the inoculating loop, and incubated at ICC for 48 hours. Once the sample is done incubating, a 1. 0 ml aliquot is taken and 15 drops of Reagent A is added along with 5 drops of Reagent B. The result is monitored at ten minute intervals for 1 hour. The results of a red color can be observed if it is positive, otherwise it is a negative result if there is no color change. The Citrate test was lightly inoculated using an inoculating needle by streaking the slants with the unknown, incubated at ICC for 48 hours, and read for a color change. The Urea hydrolysis uses Rusticating and Stuart broth that contains yeast extract, monobasic potassium phosphate, adiabatic potassium phosphate, urea, and phenol red. The broth was heavily inoculated with the inoculating loop and incubated at ICC for 24 hours. The Gelatin test uses gelatin agar that also contains beef extract and potent. The medium is stab inoculated with an inoculating needle and incubated at ICC for up to 7 days. The sample is then placed in the cold room to check for re- solidification. Results: The gram stain procedure showed to be all gram negative pink, straight rods. They had no particular arrangement or clustering. TSAR SIMI test Glucose fermentation The Methyl Red test The Vogues-Prosperous test Citrate test The Areas Test Gelatin test Conclusion: Entertainer arrogates Material Methods Gram negative cells have a thinner pedagogical layer and a lipid membrane external to the cell wall