BIO 150 - Unknown Bacterium Identification
March 26, 2014
Lap Report
Unknown Number : #12
Name of Unknown : Pseudomona aerugninosa The identification of unknown bacteria is a time-honored part of microbiology courses. It will challenge my knowledge and skill in performing laboratory techniques and my ability to critically evaluate the information obtained from these techniques. The unknown bacterium tube number 12 was picked. According to the procedures that we have been learned in class, our performances were running properly. More than 20 kinds of experiments were performed to identify unknown bacterium. The first test is gram stain. The result is pink rod which means gram negative rod shape cells. Also, in nutrient broth tube, it is observed to growth bacterium. To determine the production of protease, we do the gelatin stab. The result of this experiment is negative which has solid texture. The motility is also positive because there is no visible stabbed line. Next, the Thioglycollate test is negative because it does not require the oxygen. MR test and VP test are negative which detects no red band at the top of the tube and no pink-red color. Also, in Nitrate broth, our group observes no reddish color, but appear to be reducing nitrate due to no color change after adding zinc, so it turns out positive in this experiment. Additionally, to determine the ability to quickly break down H2O2, we do Catalase production test. We watch presence of bubbles that is positive. In oxidase test, we get positive result that presents purple color. Also, we get negative on Tryptophan test because there is no red ring at the top of the tube. Then, we get negative result both Urea and TSI test because there is no pink color for Urea test and no black color on the bottom of the tube in TSI test. Then, follow three tests results are all positive. That is deep blue color for citrate test, clear zone surrounding growth for skim milk agar