Biotechnology

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
  • Cheese/yoghurt
  • Mycoprotien (Quorn)
  • Soya sauce
• Drugs/Pharmaceuticals
  • Penicillin
  • Insulin
• Enzymes/Chemicals
  • Pectinase
  • Calcium citrate
  • Biogas
• Biomedication of waste products
  • Waste water treatment

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

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: the sum total of all chemical reactions that occur in an organism.

Primary and Secondary Metabolites

Primary 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.

Secondary Metabolites

• 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

• Temperature
• Type and addition of nutrient
• Oxygen concentration
• pH

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.

Asepsis

• Unwanted microorganisms are called contaminants.
• Aespsis: ensuring contamination does not occur via the use of aseptic technique.