1. Monera (bacteria)

2. Syllabus links 3.1.3 Monera, e.g. Bacteria Bacterial cells: basic structure (including plasmid DNA), three main types. Reproduction. Nutrition.

3. Introduction Are found everywhere! Some species can tolerate extreme environmental conditions Range in size from 0.1 to 10 μm in length Could similar such microbes be found beyond the Earth…

4. Structure of a generalised bacterium

5. Bacterial types 1. Round Are called coccus (plural cocci)Are called coccus (plural cocci) Occur in pairs chain or clustersOccur in pairs chain or clusters

6. Bacterial types 2. Rod Are called bacillus (plural bacilli)Are called bacillus (plural bacilli)

7. Bacterial types 3. Spiral Are called spirrillum (plural spirilla)Are called spirrillum (plural spirilla)

8. Reproduction – binary fission Bacteria can divide every 20 minutes if conditions are suitable This means that 1 bacterium could produce over a million bacteria in just 7 hours This explains why bacterial infection produces symptoms so quickly

9. Mutations in bacteria Bacteria reproduce asexually so all offspring are clones Sexual reproduction drives evolution so what does this mean? Bacteria can evolve fast due to the speed at which mutations appear within rapidly growing bacteria and their short life cycles So mutations are passed on quickly and this can explain for example how some bacteria have acquired a resistance to antibiotics

10. The Formation and Growth of an Endospore

11. Summary of bacterial Nutrition

12. Syllabus links 3.1.3 Monera, e.g. Bacteria Factors affecting growth.

13. Factors affecting bacterial growth 1.Temperature 2.Oxygen concentration 3.pH 4.External solute concentration 5.Pressure Journey Into Amazing Caves (IMAX) - Google Video

14. 1. Temperature Bacterial reactions affected by temperature Most grow well at temperatures between 20 and 30 o C Some can tolerate much higher temperatures with no enzymes being denatured Genes from such bacteria are often added to other bacteria that are used in biotechnology Big Movie Zone: Volcanoes of the Deep Sea [Making Of] - Google Video

15. 2. Oxygen concentration 1.Aerobic bacteria – streptococcus aureus 2.Anaerobic bacteria – Clostridium tetani 3.Faculative anaerobes – Escherichia coli 4.Obligate anaerobes – Clostridiun tetani

16. 3. pH Bacterial enzymes work at specific pH – most at around pH 7 Some can tolerate extremes of pH Helicobacter pylori can tolerate a pH of 2 http://www.hopkins- gi.org/multimedia/database/intro_7 9_H_pylori.swf

17. 4. External solute concentration Most bacteria live in less concentrated solution This principle is behind the methods of food preservation

18. 5. Pressure The growth of bacteria is inhibited by high pressures Again certain bacteria can resist and even thrive at high pressures like our friends living near thermal vents at the bottom of the ocean Biotechnological applications

19. Syllabus links 3.1.3 Monera, e.g. Bacteria CIT: Economic importance of bacteria: examples of any two beneficial and any two harmful bacteria.

20. 1 Economic importance of bacteria Bacteria can be used in the formation of certain products

21. 2 Economic importance of bacteria Genetically modified bacteria are used to make useful products like insulin, drugs, enzymes, amino acids, vitamins, food flavourings, alcohols and a growing range of new substances Escherchia coli

22. Syllabus links 3.1.3 Monera, e.g. Bacteria Understanding of the term "pathogenic".

23. Disadvantages of bacteria Bacteria cause human, animal and plant diseases – PATHOGENS Bacteria causes food decay

24. Syllabus links 3.1.3 Monera, e.g. Bacteria Definition and role of "antibiotics". Potential abuse of antibiotics in medicine.

25. 1 Antibiotics Are compounds produced by micro – organisms that stop the growth of, or kill, other micro – organisms without damaging human tissue Originally isolated by Sir Alexander Fleming in 1928

26. 2 Antibiotics Most bacteria are killed by antibiotics however there is the possibility that they might acquire a resistance against the antibiotic e.g. MRSA in hospitals Causes of this are overuse of antibiotics and failure of some patients to complete their treatment

27. Lag phase Log phase Stationary phase Decline phase Death or survival phase

28. Food processing Modern bio - processing methods involve the use of bacteria (and other organisms) to produce a wide range of foods and useful products Examples include yoghurts, cheeses, artificial sweeteners, amino acids, vitamins etc. There is also a growing trend to using micro – organisms as a source of food (single cell protein SCP) There are 2 main methods of fermentation 1.Batch culture 2.Continuous flow

29. Batch culture

30. Continuous flow

31. Differences between batch and continuous flow culture BatchContinuous flow Fixed amount of nutrient added at the start Nutrients added all of the time Micro-organisms go through the lag, log, stationary (and sometimes, decline) phases Micro-organisms maintained in the log phase all the time Product formed for a short time (and the process may start again) Product formed all the time for a long period of time

32. Advantages of batch culturing 1.It is an easier process to control than continuous flow culturing 2.The product may be needed only in small amounts 3.The product may only be needed at certain times 4.The large volume of product formed allows for some losses when it is separated and purified 5.Some organisms do not grow well for the long periods of time required in continuous flow methods