culturing microorganisms

• • “Culturing” means growing micro-organisms.
  • To accelerate growth they are often given optimal temperature, oxygen, pH and food.
  • The “food” here is called nutrient medium.
  • It can come in jelly form (agar plates) or broth form (liquid)
• If conditions are not controlled when culturing microorganisms then growth is affected.
• • In industry culturing microorganisms is often done using a fermenter.
  • Fermenters monitor and control all aforementioned factors affecting growth.
  • There are two types of fermentation; Batch fermentation and Continuous culture.
• • The processes involved in small scale cultures and industrial scale bioreactors all aim to maximise yield.
  • Yield may be a direct product e.g. Quorn
  • Yield may be a primary metabolite e.g. ethanol
  • Yield may be a secondary metabolite e.g. penicillin
• • Asepsis = the absence of micro organisms.
  • Bioreactors practice asepsis of unwanted microorganisms
• • All of this would not be possible if we didn’t use aseptic technique.
  • A lack of aseptic technique leads to contamination
  • It prevents growing organisms that would use up nutrients, oxygen and therefore decrease yield.
  • It reduces the risk of pathogenic micro-organisms developing
• Inoculation = adding microorganisms to a nutrient medium