Using Micro-organisms Flashcards
What are the different types of micro-organisms?
Bacteria Fungi Virus Protozoa (e.g. Amoeba) Algae
What are micro-organisms used for?
Medicines (e.g. Penicillin) Food Production Chemicals such as enzymes and fuels Genetic Modification Selective Breeding
What is fermentation?
The chemical breakdown of a substance by micro-organisms like yeast and bacteria, typically involving effervescence and giving off heat.
How do micro-organisms obtain energy? What occurs as this is happening?
Many micro-organisms use an external food source from their growth culture medium to obtain energy. In doing so, they change substances in the medium and are useful.
What is biotechnology?
The use of micro-organisms is make products useful for humans called biotechnology.
Give examples of the roles of micro-organisms in food production.
- Yeast, a fungus, is used to make beer, wine and bread
- Lactobacillus, a bacterium, helps to make yoghurt and cheese
- Acetobacter, a bacterium, converts ethanol in wine to vinegar
What is used to produce/use micro-organisms on a large scale?
An industrial fermenter
What is the role of the steam inlet in the industrial fermenter?
It lets hot steam enter the fermenter, cleaning and sterilising the insides. It removes chemical residue and kills any unwanted micro-organisms.
What is the role of the nutrient inlet in the industrial fermenter?
Allows nutrients needed by the micro-organisms to enter the start and occasionally during the process.
What is the role of the air inlet in the industrial fermenter?
Oxygen is required if a micro-organism respires aerobically. The air is pushed in with pressure and a filter is attached to sterilise air. The inlet is attached to a disk with holes (a spargar) that allows air to enter with pressure and helps mixing air with the contents of the fermenter.
What is the role of the acid/alkali inlet in the industrial fermenter?
To adjust the pH contents, a buffer can be introduced through the inlet.
What is the role of the cold water inlet in the industrial fermenter?
Lets cool water enter the cool water jacket.
What is the role of the cold water jacket in the industrial fermenter?
The fermenter is surrounded by a metal jacket that carries cold water to adjust the temperature of the fermenter. The water circulates in the jacket so that the contents lose heat, and warm water is taken out through another outlet.
What is the role of the water outlet in the industrial fermenter?
Warm water leaves through this outlet.
What is the role of the harvesting outlet in the industrial fermenter?
Once the products are formed, they exit through this outlet for further processing.
What is the role of the exhaust/gas outlet in the industrial fermenter?
Removes excess gas produced during fermentation to avoid pressure build up.
What is the role of the steam outlet in the industrial fermenter?
Releases steam after sterilisation.
What is the role of stirring paddles in the industrial fermenter?
Mix up the contents, keeps micro-organisms in suspension in liquid - essentially ensuring exposure to nutrients and an even temperature throughout.
What is the role of the probes in the industrial fermenter?
They monitor conditions such as pH and temperature. Information is sent to computer control systems and the environment is adjusted accordingly.
What does beer-making involve?
Involves alcoholic fermentation by yeast.
Describe the role of yeast in the production of beer.
Yeast can respire and break down glucose in the absence of oxygen to produce ethanol and carbon dioxide.
What is beer made from?
Beer is made from barley seeds which contain starch, not sugar.
What needs to happen to starch before it is fermented?
It needs to be broken down to sugars because the enzymes needed for this are produced by germinating barley seeds.