Biotechnology and genetic modification

• Microorganisms can be used by humans to produce foods and other useful substances
• Bacteria


  The most common type of microorganisms used in biotechnology
• Bacteria


  • They are capable of producing complex molecules
  • They reproduce rapidly, meaning the amount of chemicals they can produce can also rapidly increase
• Bacteria


  • There are few ethical considerations to growing them in large numbers in the laboratory
  • They possess plasmids
• Plasmids


  Small, circular loops of DNA which can be an ideal way of transferring DNA from one cell to another during genetic manipulation
• Biofuels


  Fuel made from living organisms rather than a fossil fuel like oil, coal or gas
• Biofuel production


  1. Plant material is chopped up into small pieces and mixed with yeast which respires anaerobically and produces ethanol

  2. The liquid is separated from the remaining solids and any water is removed, leaving a concentrated solution of ethanol
• In some places, this is causing concern that there is less land available for local people to grow food crops needed for survival
• Bread making


  1. Yeast is mixed with flour and water and respires anaerobically, producing carbon dioxide

  2. The carbon dioxide produced by fermentation (anaerobic respiration) of glucose is what makes bread dough rise
• Fruit juice production


  1. Fruit is chopped up and an enzyme called pectinase is added

  2. Pectinase breaks down pectin, allowing more juice to be squeezed out

  3. Adding pectinase also helps to produce a clearer juice
• Biological washing powders


  Contain enzymes that help to break down large, insoluble molecules such as fats and proteins into smaller, soluble ones that will dissolve in washing water
• Biological washing powders


  • They are effective at lower temperatures, meaning less energy (and money) has to be used in order to wash clothes to get them clean
  • They can be used to clean delicate fabrics that would not be suitable for washing at high temperatures
• Lactose intolerance


  Inability to produce the enzyme lactase, which breaks down lactose in milk
• Making milk lactose-free


  The enzyme lactase is added to milk and left to stand to break down the lactose
• Penicillin


  The first antibiotic, discovered in 1928 by Alexander Fleming
• Penicillin production


  The Penicillium mould is grown in an industrial fermenter to produce large quantities of penicillin
• Industrial fermenters

  • Conditions can be carefully controlled to produce large quantities of exactly the right type of microorganism
  • Aseptic precautions are taken to prevent contamination
  • Nutrients, optimum temperature and pH, oxygenation, and agitation are all carefully controlled
  • Waste is removed
• Mycoprotein production

  1. The fungus Fusarium is cultured in fermenters, providing it with glucose and oxygen

  2. The fungal biomass is then harvested and purified to produce mycoprotein
• Genetic modification

  Changing the genetic material of an organism by removing, changing or inserting individual genes from another organism
• Transgenic organism


  An organism that has received genetic material from another organism
• Recombinant DNA


  The DNA of an organism that now contains DNA from another organism as well
• Genetically modified organisms


  • Bacteria producing human insulin
  • Crop plants resistant to insects or herbicides
  • Crops producing additional vitamins
• Genetic modification using bacterial production of a human protein

  1. The gene is isolated using restriction enzymes

  2. The gene is inserted into a bacterial plasmid using DNA ligase

  3. The genetically engineered plasmid is inserted into a bacterial cell

  4. The bacteria reproduce, spreading the recombinant plasmid and producing the human protein
• Bacteria for genetic engineering

  • They contain the same genetic code as the organisms we are taking the genes from
  • There are no ethical concerns over their manipulation and growth
  • The presence of plasmids makes them easy to remove and manipulate