Environmental Control Of Metabolism Flashcards
What are micro-organisms
Are archea, bacteria and some species of eukaryotes
What do micro-organisms use a wide variety of
Use a wide variety of substrates for metabolism and produce a range of products from their metabolic pathways
Why are micro-organisms used
Are used because of their adaptability, ease of cultivation and speed of growth
What will many micro-organisms produce
Produce all the complex molecules required for biosynthesis, for example amino acids, vitamins and fatty acids
What do cultured micro organisms require in their growth media
Require raw materials for biosynthesis as well as an energy source
What is an energy source derived from
Derived either from chemical substrates or from light in photosynthetic organisms
The culture conditions:
- Sterility
- control of temperature
- oxygen levels
- pH
What do sterile conditions in fermenters reduce
Reduce competition with desired micro-organisms for nutrients and reduce the risk of spoilage of the product
What are the phases
- Lag phase
- log/exponential phase
- stationary phase
- death phase
What happens in the lag phase
Where enzymes are induced to metabolise substrates
What happens in the log/exponential phase
Contains the most rapid growth of micro-organisms due to plentiful nutrients
What happens in the stationary phase
Occurs due to the nutrients in the culture media becoming depleted and the production of toxic metabolites
Examples of secondary metabolites
Antibiotics
What do metabolites confer in the wild
Confer an ecological advantage by allowing the micro-organisms which produce them to outcompete other micro-organisms
What happens in the death phase
Death phase occurs due to the toxic accumulation of metabolites or the lack of nutrients in the culture
