Module Contact: Dr Tom Clarke, BIO Copyright of the University of East Anglia Version 1

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1 UNIVERSITY OF EAST ANGLIA School of Biological Sciences Main Series UG Examination MICROBIAL BIOTECHNOLOGY BIO-3C09 Time allowed: 3 hours Answer ALL questions in Section A and ONE question from Section B Write answers to EACH SECTION in a SEPARATE booklet. The maximum number of marks available for your answers in SECTION A is 50 marks The maximum number of marks available for your answer in SECTION B is 50 marks The TOTAL number of marks available for the paper is 100 Numbers in square brackets [ ] indicate the relevant mark applied to each part of the question. Notes are not permitted in this examination. Do not turn over until you are told to do so by the Invigilator. BIO-3C09 Module Contact: Dr Tom Clarke, BIO Copyright of the University of East Anglia Version 1

2 ln optical density 2 SECTION A: SHORT ANSWER QUESTIONS Answer ALL questions 1. Briefly describe the advantages and disadvantages of continuous culture compared to batch culture. [6 marks] 2. The graph below shows the growth profile of a microorganism cultured in a fermenter for 20 hours, with optical density measurements taken every hour. From this graph determine: (a) the duration of the exponential growth phase (b) the growth rate of the organism (c) the doubling time of the organism Time (hrs) [6 marks] 3. Give three reasons why you would use bacteria to overexpress a protein rather than purify it from the natural source. 4. What is meant by the term sludge age (also known as solids retention time ) in connection with activated sludge wastewater treatment? 5. In bacterial nitrification what molecule is the intermediate between ammonia and nitrite? Give its name and chemical formula. [2 marks] Section A continues on next page/...

3 3 Section A continued Name three ways of controlling filamentous bulking in wastewater treatment plants. 7. What are the four main steps of brewing? [4 marks] 8. The filamentous microfungus Fusarium venenatum is used to make single cell protein in a continuous flow fermenter for durations between hours. Explain what causes the large differences in culture run time. [2 marks] 9. What are the current problems associated with phage therapy? [6 marks] 10. Briefly list the attributes of the ideal probiotic. [5 marks] 11. How does the architecture of the enzymes that make Type I and Type II polyketide antibiotics differ? [4 marks] 12. Name three physiological processes in bacteria that are targeted by antibiotics. 13. What are phasins and what are their roles in microbes that generate bioplastics. END OF SECTION A START YOUR ANSWER TO THE NEXT SECTION IN A NEW BOOKLET Section B begins on next page/... TURN OVER

4 4 SECTION B: ESSAY QUESTION Answer ONE question [50 marks] 14. The 1989 Exxon Valdez and 2010 Deepwater Horizon Oil spills both caused significant environmental damage. Compare the methods used to clean up both spills and discuss the role of microorganisms in bioremediation methods. 15. Why is there an urgent need to develop new antibiotics? Discuss, with examples, the strategies that can be used to discover new anti-infective compounds. What are the problems faced by pharmaceutical companies in developing new antibiotics? 16. Describe how micro-organisms have been engineered to ferment pentose sugars, such as xylose and arabinose, to produce ethanol and discuss how effective the resultant engineered strains are. Why is the fermentation of pentoses important in biofuel production? END OF PAPER

5 5 BIO-3C09 EXAMINATION MARKERS [Do not print this when printing to take to Examinations Office! This is for our information only.] Question No. 1 st Marker 2 nd Marker Section A Q1 13 T Clarke G Rowley Section B Q14 T Clarke M Coleman Section B Q15 M Bibb G Rowley Section B Q16 M Coleman T Clarke