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.
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 ...view middle of the document...
The purpose is to see if the microbe can use the protein gelatin as a source of carbon and energy for growth. Use of gelatin is accomplished by the enzyme gelatins. A medium containing gelatin is used. We have all seen how gelatin forms a semisolid substance. In the medium it serves as the solidifying agent in addition to its role as a source for carbon and energy. When gelatin is used, the medium changes from semisolid to liquid and cannot be solidified. (Gelatin Hydrolysis Test) In this test the medium flows when the tube is tilted, which shows that the gelatin been digested. Unknown microorganisms use gelatin as a source of carbon and energy for growth but didn’t use starch. Urea digestion, iodole production, and H2S Production shows negative result in unknown bacteria. Unknown #79 had catalase, a protective enzyme capable of destroying the dangerous chemical hydrogen peroxide. Unknown #79 was identified Staphyloccus aureus by doing several tests as shown in Table below.
Table 1.Characteristics of Staphyloccus aureus
Characteristics Stephyloccus aureus Unknown #79
Gram reaction + +
Cell morphology coccus coccus
Cell arrangement cluster cluster
Motility - -
Pigmentation + yellow
Optimal growth temperature 37ºC...