Identification of unknown #79

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.

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