1. Problems and Profit with Waste
Biotechnology
Problems and Profit with Waste
Mr G Davidson

2. Problems with Sewage
Our modern way of life produces vast amounts of domestic and industrial waste.
Biotechnology is now finding ways of putting some of this waste to good use.
Sewage is mostly human body waste.
Densely populated parts of the country produce large amounts and to reduce the chance of disease, it must be dealt with quickly and safely.
Thursday, September 20, 2018
G Davidson

3. Sewage and Health
In the first half of the 19th Century untreated sewage was dumped into rivers which were then used for drinking water and washing.
This often resulted in disease and sometimes death.
Thursday, September 20, 2018
G Davidson

4. Untreated Sewage
Thursday, September 20, 2018
G Davidson

5. Sewage and Health
The situation improved with the construction of proper sewers and an understanding of micro-organisms.
Even today disease is spread when untreated sewage leaks into public water supplies.
This can happen after floods, earthquakes or with badly designed sewage systems.
Thursday, September 20, 2018
G Davidson

6. Sewage Treatment
In developed countries most sewage water is treated before it is reused or released into rivers or the sea.
Sewage water is treated at sewage works.
These vary in size and design but use the same basic process.
Thursday, September 20, 2018
G Davidson

7. Sewage Works
Thursday, September 20, 2018
G Davidson

8. Sewage Treatment
The main process in the treatment of sewage is its breakdown by the action of decay micro-organisms to products harmless to the environment.
During sewage treatment the oxygen required by the micro-organisms can be provided by compressed air.
Thursday, September 20, 2018
G Davidson

9. Sewage Treatment
It is important that oxygen is available to allow the complete breakdown to harmless substances which can be released safely into the environment.
Sewage contains a range of materials requiring particular micro-organisms for their breakdown.
Thursday, September 20, 2018
G Davidson

10. Sewage Treatment
Thursday, September 20, 2018
G Davidson

11. Working with Microbes
We already know how microbes can help in the manufacture of food and drink.
Also that some microbes cause disease if they enter the bodies of living things.
It is obviously important when working with microbes in the lab to adopt “safe practice”.
This avoids unwanted growth of microbes or disease.
Thursday, September 20, 2018
G Davidson

12. Safe Practice The bench is thoroughly cleaned and hands are washed.
Sterile (very clean) equipment is collected:
Petri dishes with agar food jelly
Plating loop
Culture of bacteria
Bunsen burner
Thursday, September 20, 2018
G Davidson

13. Safe Practice
Working close to the hot bunsen flame the loop is heated till red hot then allowed to cool.
A sample of bacteria is collected from the culture bottle. The culture bottle is carefully opened and closed next to the flame.
Thursday, September 20, 2018
G Davidson

14. Safe Practice
Working close to the flame the loop is now gently rubbed over the surface of the agar jelly in the dish.
The loop is again heated till red hot and allowed to cool. The dish is sealed, then labelled and placed in an incubator.
Thursday, September 20, 2018
G Davidson

15. Bacterial Culture
Thursday, September 20, 2018
G Davidson

16. Unwanted Microbes
Contamination is the presence of unwanted, possible harmful microbes.
To prevent contamination all equipment must be clean and sterilised.
Thursday, September 20, 2018
G Davidson

17. Microbes and Decay When a plant or animal dies its tissues decay.
This is mainly due to the actions of microbes.
These microbes use the dead animal or plant material as a food source to obtain energy.
Thursday, September 20, 2018
G Davidson

18. Carbon Cycle
Thursday, September 20, 2018
G Davidson

19. Nitrogen Cycle
Thursday, September 20, 2018
G Davidson

20. Food and Fuel from Waste
Upgrading waste is a way of obtaining useful products such as high quality protein foods and biogas fuel.
These are obtained from unwanted waste materials through the action of micro-organisms.
Thursday, September 20, 2018
G Davidson

21. Fuels from Fermentation
There are advantages in using fermentation fuels rather than fossil fuels.
Thursday, September 20, 2018
G Davidson

22. Fuels from Fermentation
FERMENTATION FUELS
FOSSIL FUELS
Harmless to the environment
Harmful to the environment
Easy to obtain
Difficult to obtain
Cheap to obtain
Expensive to obtain
Renewable
Non-renewable
Thursday, September 20, 2018
G Davidson

23. Alcohol as Fuel Fermentation is an energy releasing process.
This is carried out by some microbes in the absence of oxygen.
Alcohol and methane gas are products of fermentation.
Glucose YEAST Alcohol + Carbon dioxide + Energy
Thursday, September 20, 2018
G Davidson

24. Single Cell Protein
Most micro-organisms reproduce themselves much faster than the cells of plants and animals.
Industry is able to use fast growing micro-organisms to manufacture food, especially protein.
Thursday, September 20, 2018
G Davidson