Biotechnology: technology based on biology ad involves the exploitation of living organisms/biological processes to improve agriculture, animal husbandry, food science, medicine an industry.
- Food production
- Mycoprotien (Quorn)
- Soya sauce
- Calcium citrate
- Biomedication of waste products
- Waste water treatment
Micro-organisms in Biotech
Many processes involve bacteria and fungi because they:
- grow rapidly in favourable conditions
- often produce chemicals into the surrounding medium which are (fairly) easily harvested
- can be genetically engineered to produce specific products
- grow well at relatively low temperatures (lower than chemical engineering)
- not dependant on climate
- tend to generate pure products
- can often be grown using nutrient materials which are waste products to humans
Growth Curve Graph
Growth Curve Explaination
The graph shows a standard growth curve where the organisms have been placed in a closed system.
Lag phase: Organisms are adjusting to the surrounding conditions.
Log (exponential) Phase: Population doubles each generation.
Stationary Phase: Nutrient levels decrease and waste products build up. Individual orgnisms die at the same rate at which new organisms are being produced. NOTE: this would be the carying capacity of a habitat in an open system.
Decline/Death Phase: Death rate increases above reproduction rate. In a closed system, eventually all organisms will die.
Fermentation: the culturing of microorganisms an/aerobically in fermentation tanks.
Metabolism and Metabolites
Metabolism: the sum total of all chemical reactions that occur in an organism.
Primary and Secondary Metabolites
- Substances produces as part of its notmal growth.
- Includes amino acids, proteins, enzymes, nucleic acids, ethanol and lactate.
- Matches the growth in population of the orgamism.
- Substanced produced by an organism that are not part of its normal growth.
- Antibiotic chemicals are almost all secondary metabolites.
- production begins after the main growth period of the organisms and so does not match the growth in population.
Industrial Scale Fermenters
Factors to be changed are
- Type and addition of nutrient
- Oxygen concentration
Batch and Continuous Culture
- Batch - microorganisms are grown for a specific period of time, no extra nutrients added, eg Penicillin.
- Continuous - nutrients are added at regular intervals and products are removed.
- Unwanted microorganisms are called contaminants.
- Aespsis: ensuring contamination does not occur via the use of aseptic technique.