The Resistance Of Unknown Microorganisms

1935 WordsApr 24, 20158 Pages
Determination of Unknown Microorganisms Unknown Numbers 1 & 2 Justin Lucas MCB3020L 10561- M/W: 2-4pm April 21, 2015 Introduction Microorganisms are ubiquitous and play a large role in the environment. Microorganisms help some other organism in symbiotic relationships and they can also harm other organisms by causing them disease. Tests have been developed to help determine the characteristics of many microbes so that their special capabilities can be utilized for benefit. While these tests have also helped to develop substances and strategies to reduce the populations of microbes that have detrimental effects. The experiment that was performed used some of these techniques to determine the identity of some common microbes.…show more content…
Peptidoglycan is also present in large amounts in the gram positive microbes. While the gram negative microbes also contain peptidoglycan it is only present in a small amount. Other microorganisms contain other components in their cell walls that prevent them from being gram stained. There are four important ingredients in the gram stain technique. These are the 2 stains crystal violet and safranin along with Gram’s iodine and 95% ethyl alcohol. The first stain crystal violet binds to the peptidoglycan in the cell walls of the microbes. Gram’s iodine is then used to strengthen that bond. The ethyl alcohol is used as a decolorizer that removes the crystal violet stain. With large amounts of peptidoglycan in their cell walls not all of the dye will be removed from the gram positive bacteria. After decolorization the second dye safranin is used. The gram negative microbes have very little amounts of peptidoglycan within their cell walls allowing for complete removal of the crystal violet stain during decolorization. Thus safranin is now unimpeded and will stain the cell. After determining the gram staining results, viewing cell morphology, using previously determined colony morphologies and following work flow instructions the inoculation of a mannitol salt agar plate, a coagulase test, a citrate slant and urea test were all performed. The mannitol salt agar plate is used in the determination of microorganisms of the Staphylococcus genus. Within
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