Enhancement of Analytical Thinking through Scientific Investigations

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Enhancement of Analytical Thinking through
Scientific Investigations
Lesson 8

• Instructor Ann S N Lau

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• Microorganisms

http//www.thinkgeek.com/geektoys/plush/6708/zoom/
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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

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Microorganisms

• Living requirement

Water
Substratum (sometimes) Nutrient (they recycle
nutrient by acting as decomposers)
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Classification

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

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Bacteria

• E.coli, Bacillus, Cynobacteria (Photosynthetic),
• Streptococcus ??? , Staphylococcus ????
• 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
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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
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Protist

• Slime mold, diatom ??
• May be able to have slight movement

http//en.wikipedia.org/wiki/Slime_mold
http//en.wikipedia.org/wiki/Diatoms
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Microorganisms

• Environment
• Bacteria nitrogen cycle and carbon cycle
• Waste water treatment

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Microorganisms

• Food industry
• Alcoholic beverage (wine fermentation), soda,
  root beer, bread baking, xylitol production
• Probiotic supplement ???

Xylitol crystal
http//en.wikipedia.org/wiki/Xylitol
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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

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Microorganisms

• Beneficial
• or
• Harmful
• ??

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Microorganisms

• Beneficial
• Food production
• Antibiotics production
• Alcoholic fermentation
• Bakery

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Microorganisms

• Pathogenic ???
• cholera ??
• syphilis ??
• anthrax ??
• leprosy ??
• tuberculosis ???
• Plaque (Black Death)
• Normally cause infection

Anthrax
http//en.wikipedia.org/wiki/Bacteria
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Microorganisms

• Disease
• Infection
• Food deterioration

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• Experiment and assignment !!!

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Sampling of microorganisms

• Materials
• Different kinds of Bread

Conditions How to culture the samples?
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• Strategy
• Different types of bread / Why?
• Living conditions or how to culture / How?
• What do you want to sample / What?

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Bread Mold
http//encarta.msn.com/media_461516551/Black_Bread
_Mold.html
http//www.garden.com.hk/web/en_product.php?id13
languageen
http//www.glad.com.au/gladProducts/foodDetails.as
p?pId12
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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?

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Diagram showing cultivated microbes
http//www.ars.usda.gov/is/AR/archive/oct05/air100
5.htm
http//www.biofilmsonline.com/cgi-bin/biofilmsonli
ne/ed_drop_plate_methodA.html
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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
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ltBoth samples were from area 1gt
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?
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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)