Topic 6: Environmental Control of Metabolism Flashcards
The three main domains of life?
Archaea, bacteria and some species of eukaryotes
Micro organisms use a wide range of _____ for metabolism
Substrates
Micro organisms produce a wide range of ______ from the metabolic pathways?
Products
Why are microorganisms used?
There are adaptability, ease of cultivation and speed of growth
What is required when culturing microorganisms?
Their growth medium requires raw materials for biosynthesis as well as an energy source
What do many microorganisms produce?
All the complex molecules are required for biosynthesis, for example amino acids, vitamins and fatty acids
And energy source is the rived from what two categories?
Chemical substrate or from white and photosynthetic microorganisms
Culture conditions include control of what factors?
Sterility, temperature, oxygen levels and pH
What do you sterilise the conditions and fermenters reduce?
Competition with desired microorganisms for nutrients and reduce the risk of spoilage of the product
What are the four phases of growth?
Lag phase, log/exponential phase, stationary phase, death phase
What happens during the lag phase?
Enzymes are induced to metabolise substrates
What happens during the log/exponential phase?
Most rapid growth of microorganisms occur, due to plentiful nutrients
What happens during the stationary phase?
Nutrients in the culture medium become depleted and toxic metabolites are produced
What is produced in the stationary phase?
Secondary metabolites are produced, i.e. antibiotics
In the wild, what do secondary metabolites allow for?
And ecological advantage by allowing the microorganisms which produce them to all compete with other microorganisms
