IntroductionThe objective of this laboratory was to identify a culture of unknown bacteria using various differential tests. There are many reasons to know the identity of microorganisms, including finding the right antibiotic to treat infections that the bacteria may have caused. All methods and techniques used to identify unknown bacteria #79 were learned in the microbiology laboratory. Test resultUnknown#79 was grown on a TSA slope at a temperature of 370°C after two days, the microbe replicated to more than 100 microorganisms, which have cream pigments. , and convex elevations. The microbe has entire margins and convex elevations. The microbe appears to be circular and reaches a diameter of 0.4 to 0.7 micrometers. 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 a 100x oil lens, the microbe was observed as a clump formed into a shell shape. The motility of the bacteria was detected by culturing the bacteria in a special type of nutrient agar. The test was performed in a deep tube containing motility medium. We stab it with an inoculation needle in a straight line at the center of the depth and the bacteria only grows along the inoculation line, which shows that the bacteria is not mobile. Thioglycolate broth is a versatile, enriched differential medium used primarily to determine the oxygen requirements of microorganisms. In this test, growth was all over the place but was best at the top, which determined that unknown #79 was facultative anaerobic. A fermentation test is performed to detect the ability of microorganisms to ferment a specific carbohydrate. Based on the fermentation testicles, the microbe fermented glucose, sucrose, lactose and maltose. If...... middle of paper......all biochemical tests performed performed as expected, with the exception of starch and urea digestion. On the first test, the starch shows a false +, then on the second test, the result is negative. The same thing happened with urea digestion, the second test showed a false + as a negative result, matching the result of a known bacteria, Staphylococcus aureus. Therefore, it was concluded that unknown #79 was Staphylococcus aureus.ReferencesDenver Community College (2014). Introductory microbiology laboratory manual. Boston, MA; person Learning solution Oxidative/fermentative glucose test. (April 15, 2014). Retrieved April 23, 2014 from Wikipedia: http://en.wikipedia.org/wiki/Oxidative/fermentation_glucose_test Gelatin hydrolysis test. (nd). Retrieved April 22, 2014 from http://www.vumicro.com/vumie/help/VUMICRO/Gelatin_Hydrolysis_Test.htm