Biotechnology — Past, Present, and Future

Ancient

Agriculture

  • Realised the advantage of selecting seeds from the best crops and breeding the best animals
    • Selective breeding/artificial selection
  • Cross breeding different varieties resulted in stronger, healthier offspring than inbreeding
    • Hybrid vigour
  • Shift from hunting-gathering to farming
    • Increase in population density and biodiversity

Aboriginal People and Aquaculture

  • Stones and foundations 6,000 years old, e.g. canal system built by Aboriginals
    • Canals entered from the ocean to Lake Condah in Victoria
    • Evidence of eel traps in the district
  • Similar evidence in Mount William and Tolondo — connecting canals to swamps
  • Aquaculture — collecting oysters, fish, and eels to sustain communities

Food Production — Bread Making

  • Ancient evidence of the use of wild grains in the Middle East
  • Reliefs on tombs in ancient Egypt — explains the need for wheat with naturally extracted seeds
  • Evidence for the use of yeast from 2000BC in ancient Egypt
    • Began as an accident, but then was intentionally introduced to make the bread rise from the fermentation of sugar into CO2
  • Caves containing fossilised wheat have animal remains — change in animals eaten
    • Maize, beans, and potatoes in Central America
    • Rice, millet, and buffalo in Asia
    • Wheat, sheep, and goats in the Middle east

Food Production — Cheese Making

  • Involves action of bacteria on milk — 10,000 years ago
  • Process was improved
    • Understanding that enzymes could be purposely added, producing curds and whey
    • Pressing of curds removes water
    • Storage in a dry environment allows ripening — actions of surface bacteria to flavour the cheese
  • Evidence of yoghurt making — 4000 BC
    • China — bacteria fermented milk into a semi-liquid consistency, extending the time in which it could be used/stored

Classical: 1800s to Mid-20th Century

Fermentation

  • A process that results from the user of yeast — 6000 years ago in ancient Egypt
  • Bread or milled grain in a damp place began to ferment, producing alcohol
  • Sugar-rich solutions containing grain or fruit contain yeasts that ferment into alcohol
    • Brewers used barley and other grains to make beer
    • Sugar and yeast in the skin of grapes facilitate fermentation for wine-making

Medicine and Antibiotic Production

  • The use of plants to heal the sick is an ancient remedy
    • Willow bark, turmeric, opium poppy, Jesuit bark
  • Contemporary scientists create medicine from plants and fungi used in modern pharmacological drug development
  • Penicillin
    • Antibacterial product made by the fungus Penicillium
    • Discovered in 1928 by bacteriologist Alexander Fleming
    • Stabilised by the pathologist and pharmacologist Howard Florey to produce the antibiotic
    • Revolutionised the treatment of infectious diseases caused by bacteria

Modern: 1950s to Present

  • Genetic engineering — techniques used to manipulate DNA and alter the genetic makeup of an organism to meet the needs of society, the environment, and science
  • Recombinant DNA — DNA made up of DNA from more than one genome
  • Genetically modified organisms — organisms with DNA from more than one species
  • Transgenic species — species whose genome includes DNA from another species

Technology to Manipulate DNA

  • DNA Splicing
    • Cutting out genes using restriction enzymes that cut DNA at specific base sequences
    • Scientists snip DNA into smaller pieces at specific base sequences
  • DNA Amplification
    • Copying genes
    • Using the polymerase chain reaction (PCR) to make many copies of a target base sequence using a DNA polymerase enzyme. This can then be inserted into the new genome
  • Recombining DNA
    • ‘Pasting’ or inserting genes
    • DNA ligase enzyme is used to join pieces of DNA together, forming bonds in the sugar-phosphate backbone of DNA

Technology to Analyse and Visualise DNA

  • Agarose Gel Electrophoresis
    • Used to analyse DNA and then identify the ‘DNA fingerprint’ of an individual
    • DNA is fragmented and passed through a gel by an electric current — sorted in size order from smallest to longest length in base pairs
    • The distribution pattern is seen as bands on the gel — used to identify an individual or species
  • Gene Probes
    • A specific length of single-stranded DNA (20-1000 nucleotides in length) that is complementary to a known DNA sequence of a gene
    • Tagged with a fluorescent dye or radioactive atom — visualise
    • Thousands of genes are tested at a time using a micro-array
  • DNA Sequencing
    • Used to determine the exact nucleotide sequence of DNA — find the genetic code for a phenotype
    • Using gel electrophoresis or automated technologies (e.g. nanopores)
  • DNA Profiling
    • Involves the amplification of STRs (short tandem repeats) by PCR, then gel electrophoresis
    • Compare the base sequences of two or more individuals to determine relatedness — criminal profiling, paternity test

Application of Modern Biotechnology

Industrial

  • Pollution Prevention — The use of microorganisms to clean up and reduce waste; the use of enzymes toreplace harmful phosphates in washing powders; fertilisers, biopesticides, biofuels, made of plants
  • Biomaterial Production
  • Bio-Fabrication
  • Synthetic Biology

Agricultural

  • Reproductive Technologies and Genetic Diversity
    • Artificial insemination, artificial pollination, IVF, embryo transfer, cloning
    • Advantages include increased
      • Milk yield in female cattle
      • Quality of beef in cattle
      • Size of eggs and frequent laying in chickens
      • Grain yield from wheat
      • Protein in food
      • Vitamin content in food (e.g. golden rice)
    • Include using genetically engineered crops to address hunger in poor and developing countries
    • There is concern about a loss of genetic diversity and fair sharing of benefits from GM crops
  • Conservation Biology Applications 
    • Mapping relatedness in animals — design breeding programs to maximise diversity and hybrid vigour 
    • Artificial insemination for animal conservation 
    • Captive breeding-program 
    • Banks for animal genetic material — cryogenic preservation of animal genes for biodiversity 

Medical

  • Gene Therapy — Delivering normal functional genes to individuals who are lacking the functional copy, and as a result, suffer from a genetic disorder.
  • In Vitro Fertilisation (IVF) – Greater success rate thanks to improvements in scientists’ understanding of endocrinology and reproduction; overcoming infertility and genetic disorders