Fermentation is an important process in biotechnology. The booklet contains a range of practicals and information.
This activity focusses onto the fermentation of sugar solution to produce bioethanol. Details can be found in the accompanying booklet. Look for activity A3 from page 10 and on page 27. Students sheets are on pages 36 and 37. Slide 8 onwards in part 2 of the presentation can be used to introduce the activity.
The fermentation is set up on week one and then ethanol is distilled off the following week.
You may want to give students a homework before the first lesson to revise respiration. Then run a quick ‘pop quiz’ activity prior to setting up the experiment.
The activity suggests leaving the flasks at 25oC. In practice, just leave the solutions in a warm room. Using bungs with bubble traps inserted, instead of cotton wool plugs, will allow the formation of carbon dioxide gas to be seen. This can be an additional learning point and help to link the process to anaerobic respiration.
Industrially, ethanol is increasingly being produced using genetically-modified bacteria. Fermentation of lignin (wood) as a source of carbohydrate is also being developed as this reduces the need to use a food crop for fuel production.
As an extension activity, or homework, students could write a discussion of the statement: Should food crops be used for fuel production? This will allow them to develop skills in extended writing and construction of an argument.