2.6 - Environmental control of metabolism Flashcards
What are some examples of micro organisms?
Archaea, Bacteria and some species of Eukaryotes
What is an Aseptic technique?
A set of practices that protects someone from contamination from a microbe
Why do we use Aseptic techniques?
- To prevent contamination of the microbe we are growing
- Stop other microbes competing and using up resources and reducing yield
- To prevent the microbe we are culturing contaminating the environment, it may be harmful to human health
What are 2 methods of Aseptic techniques?
Computer controlled fermenter and product monitoring
What do computer controlled fermenters do?
Grow micro-organisms on a vast scale to produce useful products (e.g. Antibiotics)
What are the 4 phases of growth?
Lag, Log/Exponential phase, Stationary, Death
What is a Lag phase?
Where enzymes are induced to metabolise substrates
What is the Log/Exponential phase?
This phase contains the most rapid growth of micro-organisms due to plentiful nutrients
Why does the Stationary phase occur?
Due to the nutrients in the culture media becoming depleted and the production of toxic metabolites. Secondary metabolites are also produced such as antibiotics
Why does the Death stage occur?
Due to the toxic accumulation of metabolites or the lack of nutrients in the culture
Why are micro-organisms used?
They use a wide variety of substrates, and they’re used since their adaptability, ease of cultivation and speed of growth
What do micro-organisms produce?
Complex molecules required for biosynthesis (e.g. amino acids)
What is a Viable cell count?
Involves counting only the living micro-organisms
What is a Total cell count?
Involves counting viable and dead cells
