Question: E.i. Axenic Culture Is A Culture Where A Single Organism Or Species Is Isolated From A Mixture Of Microbes And Is Free From Any Other Organisms Which May Act As Contaminants. This Axenic Culture Is Important As It Helps In The Study Of Animals Which Are In A Parasitic And Symbiotic Relationship In A Controlled Environment. Ii. The Culture With Only …

Question: E.i. Axenic Culture Is A Culture Where A Single Organism Or Species Is Isolated From A Mixture Of Microbes And Is Free From Any Other Organisms Which May Act As Contaminants. This Axenic Culture Is Important As It Helps In The Study Of Animals Which Are In A Parasitic And Symbiotic Relationship In A Controlled Environment. Ii. The Culture With Only …

(e) You have decided that it is essential to isolate axenic cultures from the mixture of microbes in the nutrient agar in (c)

E.i. Axenic culture is a culture where a single organism orspecies is isolated from a mixture of microbes and is free from anyother organisms which may act as contaminants. This axenic cultureis important as it helps in the study of animals which are in aparasitic and symbiotic relationship in a controlledenvironment.

ii. The culture with only a single type of organism is obtainedfrom an existing mixed culture by subculturing it. Thissubculturing is done by a series of dilutions to get very fewsingle organisms, and then these subcultures are allowed to growand multiply until particular organisms are able to be identified.After this subculturing step, the selection of only the desiredorganism is done to produce an axenic culture.

These selected organisms will be later again subcultured toavoid any contamination taking place due to the growth of unwantedorganisms on the agar that provides an enriched medium for itsgrowth.

F) i. The results show that B1 and B2 are Gram Negativeorganisms but this result is not reliable as this bacterial culturewas incubated for more than 24 hours which actually results in thedegeneration of the cell wall. This degeneration of the cell wallwill allow the crystal violet stain to be washed off and instead bestained with safranin dye.

ii. The appearance of green colour on staining with malachitegreen means that the isolated B1 bacteria shows the presence ofendospores.

I need help with questions from F(iii) to H

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(e) You have decided that it is essential to isolate axenic cultures from the mixture of microbes in the nutrient agar in (c) prior to subsequent analyses. (i) Define axenic culture. Why is it important? (1,2 marks) (ii) Explain how axenic cultures can generally be produced from the microbial mixture in (6 marks) (d). (1) Using the method described in (e), you finally end up with two pure bacterial (B1 and B2) and two pure fungal (F1 and F2) cultures. You have decided to identify the bacteria first by running some tests. (i) The bacterial cultures were incubated in an incubator for 48 hours at 37°C before Gram staining was performed. Results have indicated that both bacteria isolates B1 and B2 were Gram-negative. Is the result reliable? Explain. (1, 4 marks) Staining with malachite green has revealed green-colored entities in isolate Bl under the microscope. What does this mean? (1 mark) (iii) A simple literature review has revealed that isolate Bl is likely Bacillus or Clostridium. Devise an experiment to identify Bl. (6 marks) (iv) With the help of a fellow microbiologist, you have managed to identify isolate B2 as Vibrio cholerae. List the fundamental differences between isolate B1 and B2. (5 marks) (g) You now turn your attention to the two isolated fungal isolates (F1 and F2). Briefly describe how you can reliably identify the fungal specimens F1 and F2 down to a generic level. (4 marks) (h) You have successfully cultured fungi Fl and F2 using Potato Dextrose Agar (PDA). However, you think that it is best to assess whether these are truly fungi which induces the formation of agarwood and not undesired contaminants introduced during the experiment. (i) Suggest a plan of action for this assessment. (6 marks) (ii) This assessment is associated with a theory in microbiology (covered in class). Explain this theory and why it is important. (4 marks)