1. The document discusses microbiology techniques used to culture bacteria, including aseptic technique, autoclaving equipment, and inoculating agar plates. 2. It also covers the classification of microbes into three domains: Archaea, which live in extreme environments; Eubacteria, which are found in most habitats and include heterotrophs, photosynthetic and chemosynthetic autotrophs; and Eukaryotes. 3. The differences between Archaea and Eubacteria include their cell walls, membranes, ribosome size, and the presence or absence of histones and introns in their genes.

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

2. As you watch the film clip....Ask yourself the following questions...What THREE words come to mind when you first see the flatWhy do you think James´s flat makes you feel the way you do?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 techniqueb)learning how to CULTURE bacteria c) understanding how to classify bacteria

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

7. Before we begin!

8. Using micro-organismsMicro-organisms can be grown by man. They need certain nutrients which are often contained in an agar medium: carbohydrates (energy source)

9. mineral ions

10. sometimes +protein, vitaminsThis is poured into a petri dish.ContaminationIs when unwanted, possibly harmful microbes grow. You don’t want this to happen.

11. Microbiological techniques12345Aberdeen UniversityLab coat to protect clothingMicrobes not carried outHands washed before & after, gloves wornMicrobes not carried outSmooth, non-absorbent work surface (plastic) cleaned with disinfectant before & afterSterile petri dishes of nutrient agar readyAutoclave / pressure cooker to sterilise glassware (>120oC, 20min)Less chance of unwanted microbes getting in (contamination)Microbes killedMicrobes killed

12. Techniques (continued)67Lid held over petri dish during inoculationWire loop & bottles flamed before useMicrobes killedLess chance of unwanted microbes getting in

13. 8Bin lined with plastic bag for safe disposal of used materials by autoclaving9Inoculated dish sealed with tapePrevents microbes getting in or outPrevents microbes getting out. Microbes killed

14. Now it´s your turn!Find a partnerDecide what aspects of bacterial culture you are going to investigatee.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!Prepare your work surface and agar plateInnoculate!Seal your petri dish and don´t forget to label it with your names and the dateRe-sterilise your work surfaceWash your hands!

15. Classificationis the grouping together of things on the basis of features they have in common.

16. In 1996 scientists found the reasons for the reclassification of living organisms into three domains.

17. Large collaboration of scientists deciphered the full DNA sequence of every gene of bacteria called Methanococcusjannaschii.

18. This archaebacterium lives at 85oC, a temperature lethal for regular bacteria as well as multicellular plants and animals.

19. Only 44% of this archaebacterium genes resemble those in eubacteriaor eukaryotes.Differences between organisms of three domains:Histones – proteins associated with the three dimensional structure of chromosomal DNA, present only in eukaryotic cells.Introns – segments of non-coding DNA within genes that are removed before translationSize of ribosomes – bacterial ribosomes (70S) – smaller than eukaryotic ones (80S).Structure of cell wallsStructures of cell membranes

20. Classification of BacteriaArchaebacteria: extremistsEubacteria: HeterotrophsPhotosynthetic autotrophsChemosynthetic autotrophs

21. ArchaeaArchaebacteria (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.