Biology 9700 · AS & A Level · Principles of genetic technology

Principles of genetic technology — practice question

Fusarium venenatum, a filamentous fungus, may be cultivated in a fermenter and collected as mycoprotein. This food is marketed in several countries. The fungus is maintained in continuous culture in $150000\,\text{dm}^3$ airlift fermenters, where bubbles of compressed air supply oxygen and mix the contents. As it grows as thin, branched filaments, the harvested mycoprotein has a naturally chewy, fibrous texture. About $300\,\text{kg}$ of fungus may be harvested each hour.
(a)[2]

Explain the meaning of the term continuous culture.

(b)[4]

After roughly six weeks, mutants may develop within the fungal population, for example a form with more highly branched filaments. The fermenter is drained, cleaned and restarted with the original strain of $F.$ venenatum every six weeks. Explain why the fermentation process should be halted before mutants develop.

(c)[1]

Approximately $12\%$ of the harvested fungus is protein. Calculate the approximate mass of protein harvested in one day during continuous culture. Show your working.

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