1. Meet the Microbes!! Hina´s magical mystery Microbiology lab!

2. As you watch the film clip.... Ask yourself the following questions... a)What THREE words come to mind when you first see the flat b)Why do you think James´s flat makes you feel the way you do? c)What health risks are posed by keeping the flat in this condition?

3. Now look at these pictures... In groups list 5 differences between them!

4. Microbes are everywhere!

5. What is microbiology? Discuss the word with the person next to you! A little introduction! So what are we doing this session? a)learning ASEPTIC technique b)learning how to CULTURE bacteria c) understanding how to classify bacteria

6. Working with micro-organisms To produce useful products, uncontaminated cultures of microbes are required. This requires certain precautions and sterile techniques to be used. autoclave

7. Before we begin!

8. Using micro-organisms  carbohydrates (energy source)  mineral ions  sometimes +protein, vitamins Micro-organisms can be grown by man. They need certain nutrients which are often contained in an agar medium: This is poured into a petri dish. Contamination Is when unwanted, possibly harmful microbes grow. You don’t want this to happen.

9. Aberdeen University Microbiological techniques Lab coat to protect clothing Hands washed before & after, gloves worn Microbes not carried out 1 2 Smooth, non-absorbent work surface (plastic) cleaned with disinfectant before & after Microbes killed 3 Sterile petri dishes of nutrient agar ready Less chance of unwanted microbes getting in (contamination) 5 4 Autoclave / pressure cooker to sterilise glassware (>120 o C, 20min) Microbes killed

10. Techniques (continued) 6 Wire loop & bottles flamed before use Microbes killed 7 Lid held over petri dish during inoculation Less chance of unwanted microbes getting in

11. Prevents microbes getting out. Microbes killed 8 Inoculated dish sealed with tape Prevents microbes getting in or out 9 Bin lined with plastic bag for safe disposal of used materials by autoclaving

12. Now it´s your turn! 1.Find a partner 2.Decide what aspects of bacterial culture you are going to investigate e.g. The difference between soap and disinfectant Effectiveness of handwashing? Bacteria from different parts of your body Effect of chemicals on bacterial growth Anything else you can think of! 3.Prepare your work surface and agar plate 4.Innoculate! 5.Seal your petri dish and don´t forget to label it with your names and the date 6.Re-sterilise your work surface 7.Wash your hands!

13. Classification is the grouping together of things on the basis of features they have in common.

14. In 1996 scientists found the reasons for the reclassification of living organisms into three domains. Large collaboration of scientists deciphered the full DNA sequence of every gene of bacteria called Methanococcus jannaschii. This archaebacterium lives at 85 o C, a temperature lethal for regular bacteria as well as multicellular plants and animals. Only 44% of this archaebacterium genes resemble those in eubacteria or eukaryotes.

15. Differences between organisms of three domains: Histones Histones – proteins associated with the three dimensional structure of chromosomal DNA, present only in eukaryotic cells. Introns Introns – segments of non-coding DNA within genes that are removed before translation Size of ribosomes Size of ribosomes – bacterial ribosomes (70S) – smaller than eukaryotic ones (80S). Structure of cell walls Structure of cell walls Structures of cell membranes Structures of cell membranes

16. Classification of Bacteria Archaebacteria: extremists Eubacteria: – Heterotrophs – Photosynthetic autotrophs – Chemosynthetic autotrophs

17. Archaea Archaebacteria (archaios – ancient, bakterion – rod) live in extreme environments where few other organisms survive.They are believed to have been the first forms of life on Earth. Methanogenic archaebacteria – inhabit anaerobic habitats and give off methane as a product of their metabolism. They live in the guts of cattle and are responsible for the intestinal gases that cattle produce.Methanogenic archaebacteria – inhabit anaerobic habitats and give off methane as a product of their metabolism. They live in the guts of cattle and are responsible for the intestinal gases that cattle produce. Halophilic archaebacteria – live only in very salty conditions such as salt flats, where heat from the Sun has evaporated sea water.Halophilic archaebacteria – live only in very salty conditions such as salt flats, where heat from the Sun has evaporated sea water. Thermoacidophilic archaebacteria – live in hot acidic springs where temperatures may exceed 100 o C and the pH may be as low as 2.Thermoacidophilic archaebacteria – live in hot acidic springs where temperatures may exceed 100 o C and the pH may be as low as 2.

20. We identify them by: Investigating their growth requirements Looking at their size and shape Studying their reactions to specific stains (such as Gram stain) Eubacteria Eubacteria (eu –good, true, bakterion – rod) make up the remaining bacteria. They are found in all but the most extreme environments, in soils, sediments, floating free in air or water, in and on the other organisms. They occur mainly as single cells but also group together in chains or clusters.

21. To summarise: What is meant by the five kingdom classification system? What is meant by the five kingdom classification system? What evidence is there that archaebacteria were the first forms of life on Earth? What evidence is there that archaebacteria were the first forms of life on Earth? What are the main differences between archaebacteria and eubacteria? What are the main differences between archaebacteria and eubacteria?