Comparing The Cellular Morphology Of Table 2

1731 WordsMar 26, 20177 Pages
Comparing the cellular morphology of table 2 to their respective pure culture in table 3. B. cereus presented with a white colony, round colony morphology, smooth margins and flat elevation in both pure culture and isolated culture; E. coli presented with a Yellow colony, round colony morphology, smooth margins, and flat elevation; S. aureus presented with a White colony; round colony morphology, smooth margins, and raised elevation. In comparison of the cellular morphology of each bacterium in the mixture (table 2) to their respective pure culture (table 3) showed that Bacillus cereus, Escherichia coli, and Staphylococcus aureus are present in the mixed culture as their respective cellular morphology was the same as compared to the pure…show more content…
However, additional tests can be performed to further differentiate the three bacteria from one another. One example is the BactiStaph test for the Staphylococcus genus (in this case S. aureus) (Summers, Brookings and Waites, 1998). Which relies on the principle of detecting coagulase (clumping factor) using fibrinogen, and detecting protein A with immunoglobulin G. As result of these surface markers present on most strains of S. aureus will test positive for BactiStaph test (Summers, Brookings and Waites, 1998; Harris, Foster and Richards, 2002); Another test to differentiate E. coli and B. cereus from S. aureus is by the basis of motility. Using either MAST motility test or hanging drop method differentiate E. coli and B. cereus from S. aureus, as the two bacteria are motile (Mitchell and Kogure, 2006); Lastly, since neither E. coli nor S. aureus produce endospores, whilst B. cereus under the right conditions does produce endospores. By using techniques such as Dipicolinic acid assay or Schaeffer-Fulton spore stain can be used to assess the presence of spores in B. cereus (Hindle & Hall, 1999). Three plating methods can be used to produce well separated single colonies, streak plate procedure, spread plate and the pour plate procedure (Sanders, 2012). Spread plate procedure is used to separate microbes contained within a small sample volume (e.g. mixed broth culture) which is then spread over an agar
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