Biological Resources

• Uses of Microorganisms (like Bacteria and Yeast):

  • Bacteria are used to ferment AND break down Dairy products, such as yoghurt and cheese. Bacteria is also used to produce vinegar
  • Yeasts are used to bake Bread and brew Beer, an Alcohol
  • Some microorganisms can be used to produce Food Additives, such as flavourings
• Yoghurt is a product of Milk Fermentation by the bacterium Lactobacillus

  • Lactobacillus uses the lactose in milk as its substrate for Anaerobic respiration, which converts it into Lactic Acid and releases energy in the process.

  The result of Lactic Acid is what contributes to the distinctive taste and texture of the yoghurt

  
• How Yoghurt is made:

  1. ALL equipment is sterilised to kill unwanted Microorganisms and prevent contamination
  2. The milk is pasteurised at 72°C for 15 seconds to kill any harmful microorganisms. Then, the milk is cooled and Lactobacillus Bacteria is added
  3. The mixture is incubated at 40-45°C for several hours, while the Lactobacillus Bacteria ferment the Lactose in the milk
  4. The Lactobacillus bacteria convert the lactose into lactic acid, which sours and thickens the milk, forming yoghurt.
  5. The yoghurt is then stirred and cooled stopping the action of the Lactobacillus bacteria
• INDUSTRIAL FERMENTATION:

  Microorganisms, such as bacteria and fungi, can be used to create valuable substances, such as Penicillin and Insulin

  • To ensure their optimal growth, these microorganisms are grown in large tanks known as Fermenters, where conditions like temperature, pH, and nutrient levels can be monitored and controlled at all times
• What an Industrial Fermenter looks like:

  A) Ph

  B) Temperature

  C) Water In

  D) Waste

  E) Water out

  F) Jacket

  
• In an Industrial Fermenter:

  • [Air pump] introduces air (containing oxygen) into the fermenter. This is required for aerobic fermentations, where Microorganisms need Oxygen to respire
  • [Paddles] are used for mixing and ensuring an equal distribution of nutrients within the culture medium, increasing the rate of reaction
  • [Nutrients] are added to the culture medium to support the growth and metabolic activity of the Microorganisms

  
• Disadvantages to SELECTIVE BREEDING:

  • Reduces the Gene Pool of the population (so you will get a smaller pool of Alleles)
  • Because the best individuals BOTH have the 'good gene', (which makes them related) this can lead to Inbreeding

  --> This makes the offspring prone to diseases, OR inherited defects, because of their small Gene Pool

  • Less variation in a Population, so if one individual gets infected, ALL of them might be infected
• Fish Farming:

  Fish Farms are large enclosures or tanks designed to provide controlled environments for the growth of fish, mainly for Human Consumption
• EFFICIENT Fish Farming:

  • [Cages] The fish are put in cages to limit their movement, conserving energy for growth. They also help prevent INTERspecific Predation, attacks from birds and seals
  • [Diet] They receive a diet of high Protein food designed to increase their energy intake, which allows the fish to grow bigger and faster
  • [Young Fish] Are nurtured in specialised tanks to increase their survival rate. Separating the Young fish from the Adults, we stop the adults from eating the young, preventing INTRAspecific Predation

  
• EFFICIENT Fish Farming:

  • [Selective breeding] is used to enhance productivity by creating less aggressive, faster-growing fish
  • [Diseases and parasites] Such as sea lice, can be controlled with Pesticides or Biological Pest Control methods. For example, Wrasses, small fish, are used to eat the lice off the salmon

  
• [Increasing Crop Yields]

  GREENHOUSES:

  • Greenhouses keep plants free from Pests and Diseases
  • They TRAP the Sun’s heat, keeping the plants WARM
  • They also help farmers control the Water that’s supplied to the Crops

  ——> By INCREASING the Temperature, CO2 Concentration AND the Light Available, we can increase the RATE of Photosynthesis for the plants.

  This makes them grow bigger and faster; Crop Yields will be higher

  
• [Selective Breeding] this involves the breeding of animals with particular characteristics to produce offspring with more DESIRABLE characteristics

  
• How Yoghurt is made:

  1. ALL equipment is STERILISED to kill unwanted Microorganisms and prevent contamination
  2. The milk is pasteurised at 72°C for 15 seconds to kill any harmful microorganisms. Then, the milk is COOLED and Lactobacillus Bacteria is added
  3. The mixture is incubated at 40-45°C for several hours, while the Lactobacillus Bacteria ferment the Lactose in the milk
  4. The Lactobacillus bacteria convert the lactose into lactic acid, which sours and thickens the milk, forming yoghurt.
  5. The yoghurt is then stirred and cooled, stopping the action of the Lactobacillus bacteria