E nhancement of A nalytical T hinking through S cientific I nvestigations

1. Enhancement of Analytical Thinking through Scientific Investigations Instructor: Ann S N Lau Lesson 8

2. Microorganisms http://www.thinkgeek.com/geektoys/plush/6708/zoom/

3. Microorganisms • The oldest form of life on earth • Sometimes called “microbes”, especially the disease-causing species • Small in size, barely be seen by naked eyes, requires the use of microscope for investigation • Found in environment, food, industrial, medical; beneficial or harmful • Unicellular or multicellular

4. Microorganisms Living requirement Water Substratum (sometimes) Nutrient (they recycle nutrient by acting as decomposers)

5. Classification • Unicellular or multicellular Examples - Bacteria (unicellular) Fungi (e.g. yeast) (unicellular or multicellular) Protist (e.g. one-celled algae: diatom, slime- mold, etc.)

6. Bacteria • E.coli, Bacillus, Cynobacteria (Photosynthetic), Streptococcus 鏈球菌 , Staphylococcus 葡萄球菌 • Small in size (micrometers 10-6) • Can grow anywhere, reproduce by binary fission or budding • Cell wall, lack of organelles, no define nucleus Staphylococcus http://en.wikipedia.org/wiki/Microorganism E.coli Cynobacteria http://en.wikipedia.org/wiki/Microorganism http://en.wikipedia.org/wiki/Bacteria

7. Fungus • Saccharomyces cerevisiae, Candida species, Penicillium, Aspergillus species (bread mold), mold species that cause athletes foot etc. • Can be beneficial or harmful • Use in food industry, but some species can cause food to deteriorate http://en.wikipedia.org/wiki/Aspergillus Aspergillus niger Candida albicans http://en.wikipedia.org/wiki/Aspergillus http://en.wikipedia.org/wiki/Yeast

8. Protist • Slime mold, diatom 矽藻 • May be able to have slight movement http://en.wikipedia.org/wiki/Slime_mold http://en.wikipedia.org/wiki/Diatoms

9. Microorganisms • Environment Bacteria – nitrogen cycle and carbon cycle Waste water treatment

10. Microorganisms • Food industry Alcoholic beverage (wine fermentation), soda, root beer, bread baking, xylitol production Probiotic supplement 益生菌 Xylitol crystal http://en.wikipedia.org/wiki/Xylitol

11. Microorganisms • Biotechnology • Short life-cycle with simple genome • Good study model in biotechnology • Used in gene cloning, recombinant protein and DNA technology • Production of insulin, growth hormone, etc. • Genetics studies

12. Microorganisms Beneficial or Harmful ??

13. Microorganisms Beneficial • Food production • Antibiotics production • Alcoholic fermentation • Bakery

14. Microorganisms • Pathogenic 致病的 cholera 霍亂 syphilis 梅毒 anthrax 炭疽 leprosy 痲瘋 tuberculosis 結核病 Plaque (Black Death) Normally cause infection Anthrax http://en.wikipedia.org/wiki/Bacteria

15. Microorganisms • Disease • Infection • Food deterioration

16. Experiment and assignment!!!

17. Sampling of microorganisms Materials: Different kinds of Bread Conditions: How to “culture” the samples?

18. Strategy Different types of bread / Why? Living conditions or how to culture / How? What do you want to sample / What?

19. Bread Mold http://encarta.msn.com/media_461516551/Black_Bread_Mold.html http://www.garden.com.hk/web/en_product.php?id=13&language=en http://www.glad.com.au/gladProducts/foodDetails.asp?pId=12

20. How to make use your bread? • Cut it into equal size? Use as original size? • Record the nature of the bread used? • Sampling area – should we sample dirty area or clean area? Or both? • Any control experiment required? What kind of “Control”? • Method of sampling: basically by contact or swabbing (How hard should I swab?) • What kind of microorganisms are expected to be collected?

21. Diagram showing cultivated microbes http://www.ars.usda.gov/is/AR/archive/oct05/air1005.htm http://www.biofilmsonline.com/cgi-bin/biofilmsonline/ed_drop_plate_methodA.html

22. Zip bag Zip bag Bread Bread Condition 1 Nature of the bread: (Brand name, characteristics, or you can do a summary table as a key underneath) Sampling area: Method of sampling: Any moisture added? How long did it take to have the first lawn of microorganism appears? Any moisture added into the bag before culturing? Observation: Type(s) of microorganism appear(s ) onto the day: Condition 2 Nature of the bread: (Brand name, characteristics, or you can do a summary table as a key underneath) Sampling area: Method of sampling: Any moisture added? How long did it take to have the first lawn of microorganism appears? Any moisture added into the bag before culturing? Observation: Type(s) of microorganism appear(s ) onto the day:

23. Zip bag Zip bag Zip bag Zip bag Bread Bread Bread Bread <Both samples were from area 1> Consider different sample treatment being collected in the same way? (e.g. under sunlight, in refrigerator, in a moist / damp area, etc.) A B A from area 1 and B from area 2 Both treated in the same way but sampled from different areas?

24. Assignment – Submit a proposal • A comprehensive record of your experiment (method / strategy) • A complete record of your result e.g. What kind of microorganism you have collected? Matching it with reference book / internet source? Comparisons of your result with different sampling and treatment method? • Take photos if necessary • Organize your method and result in a report format • Each group submit one report and a short PowerPoint Presentation (5 minutes, 10-15 slides)

25. How moldlookslike? Start up of mold development on culturing medium Well-developed mold in the same medium

26. Where does mold grow? http://www.moldinspector.com/mold_photo.htm

27. Bread mold http://encarta.msn.com/media_461516551/Black_Bread_Mold.html http://www.nimr.mrc.ac.uk/news/2006/wellcome_img/mould/ Credit: Liz Smith / Wellcome Images

28. Other microorganisms…… Candida albicans (yeast) Listeria monocytogenes(bacteria) MRSA (Methicillin-resistant Staphylococcus aureus) 抗藥性金黃色葡萄球菌 E.coli O157 Salmonella 沙門氏菌 http://www.bd.com http://www.oxoid.com