BIOL 260-Microbiology (Bacterial Unknown Lab report) Report

BIOL 260-Microbiology (Bacterial Unknown ) - Lab Report Example On the basis of morphology after performing Gram staining one was identified as Gram positive Cocci while other was identified as Gram negative Bacilli. Further, colony characteristics, biochemical tests as well as specific tests the micro-organisms were carried out to reach to the correct identification of the micro-organism. The Catalase test was performed which was positive, eliminating the chances of unknown sample to be Streptococcus (which is catalase negative). Further, Mannitol fermentation was positive for this unknown sample which eliminates the chances of S. aureus (Mannitol negative) from the sample. Further, presence of pigment was observed to eliminate the chances of S. epidermidis and S. saprophyticus (both these organisms do not have pigment). Since the colony color was found to be yellow the identification tapers to the presence of Micrococcus sp. In order to further segregate the Micrococcus sp. presence or absence of glucose fermentation was observed. The result was negative confirming the absence of Micrococcus varians (which displays glucose fermentation) and presence of Micrococcus luteus (does not display gluc ose fermentation). The second unknown bacteria was aerobic as it was catalase as well as oxidase positive. Since it is Gram negative aerobic bacilli the identification tapers to the possibility of either Helicobacter salinarum, Alcaligenes faecalis, Pseudomonas aeruginosa. Since citrate utilization was positive in the biochemical test it could be Pseudomonas aeruginosa or Alcaligenes faecalis. To eliminate one of the species to taper the identification further, growth was observed which was moderate and hence probability of Pseudomonas was eliminated (as Pseudomonas display abundant growth). Manipulative skills and cognitive microbiological knowledge are essential for the identification of microorganism beyond