Essential Idea:
Microorganisms can be used and modified
to perform industrial processes
Understandings:
- Microorganisms are metabolically diverse
- Microorganisms are used in industry because they are small and have a fast growth rate
- Pathway engineering optimises genetic and regulatory processes within microorganisms
- Pathway engineering is used industrially to produce metabolites of interest
- Fermenters allow large-scale production of metabolites by microorganisms
- Fermentation is carried out by batch or continuous culture
- Microorganisms in fermenters become limited by their own waste products
- Probes are used to monitor conditions within fermenters
- Conditions are maintained at optimal levels for the growth of the microorganism being cultured
Applications:
- Deep-tank batch fermentation in the mass production of penicillin
- Production of citric acid in a continuous fermenter by Aspergillus niger and its use as a preservative and flavouring
- Biogas is produced by bacteria and archaeans from organic matter in fermenters
Skills:
- Gram staining of Gram-positive and Gram-negative bacteria
- Experiments showing zone of inhibition of bacterial growth by bactericides in sterile bacterial cultures
- Production of biogas in a small-scale fermenter