| Date | November 2020 | Marks available | 1 | Reference code | 20N.3.SL.TZ0.8 |
| Level | Standard level | Paper | Paper 3 | Time zone | TZ0 / no time zone |
| Command term | Outline | Question number | 8 | Adapted from | N/A |
Question
The diagram shows an aerated fermenter commonly used in biotechnology.
[Source: Adapted from GYassineMrabetTalk, CC BY-SA 3.0
https://creativecommons.org/licenses/by-sa/3.0, via Wikimedia Commons.]
Outline a reason for inserting steam into the fermenter before fermentation.
Describe how optimal temperature is maintained inside the fermenter.
Explain how penicillin can be produced in a fermenter.
Markscheme
sterilizes/kills unwanted microorganisms in the fermenter;
cold water is added to the jacket if the temperature is too high;
a. takes place in (deep-tank) batch fermenters;
b. Penicillium (fungus) is grown on sugar/starch/nutrients;
c. penicillin is produced when the nutrients are used up;
d. penicillin secreted by the fungus is separated and purified;
e. occurs under aerobic conditions/Penicillium is an obligate aerobe;
