Bacteria in the news'

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Bacteria in the news.
Please reflect on any questions, comments, or
concerns relating to this.
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The numbers.

• University of Georgia - estimates the number of
  bacteria on earth to be five million trillion
  trillion that's a five with 30 zeroes after it.
• 5,000,000,000,000,000,000,000,000,000,000!!!
• Bacteria inside all animals combined including
  humans1
• By far the greatest numbers are in the
  subsurface, soil and oceans.
• Scientists have found these cells 40 miles high
  in the atmosphere and beneath the ocean floor
  some seven miles deep.

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Bacteria.

• Cell type Prokaryotes
• Domain Bacteria (Eubacteria)
• Kingdom Monera
• Shapes Cocci, Helices/Spirilla, Bacilli
• Colony Size, shape, pigmentation

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Colony Characteristics.

• Abundance of Nutrients Bacteria grow FAST!
• Different types of bacteria will produce
  different-looking colonies (colony morphology).
• Bergey's Manual of Determinative Bacteriology
  (commonly termed Bergey's Manual) describes the
  majority of bacterial species identified by
  scientists so far.
• Form
• Elevation
• Margin
• Surface
• Opacity
• Chromogenesis (coloration)

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Form

• What is the basic shape of the colony?

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Elevation.

• What is the cross sectional shape of the colony?
• Turn the Petri dish on end.

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Margin.

• What is the magnified shape of the edge of the
  colony?

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Surface, Opacity, Chromogenesis

• Surface How does the surface of the colony
  appear?smooth, glistening, rough, dull (opposite
  of glistening), rugose (wrinkled), etc.
• OpacityFor example, transparent (clear), opaque,
  translucent (almost clear, but distorted vision,
  like looking through frosted glass), iridescent
  (changing colors in reflected light)
• ChromogenesisFor example, white, buff, red,
  purple, etc.

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What types of bacterial colonies?
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Gram characteristics.

• The purpose of Gram staining is to visually
  differentiate groups of bacteria
• Identifies chemical and physical properties of
  their cell walls.
• Gram positive Bacteria that are stained violet
  or dark blue, indicating high amount of
  peptidoglycan in the cell wall and typically
  lacking an outer membrane.
• Gram negative Bacteria that do not retain a
  stain, looking red/orange, indicating a small
  amount of peptidoglycan or a secondary outer
  membrane.

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Gram positive bacteria.

• Retain a blue, violet
• color

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Gram negative bacteria.

• Does not retain blue dye, is stained a
  reddish-orange color.

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Issues

• Among pathogenic (disease causing) bacteria, gram
  negative are more threatening!!!
• WHY????
• An outer membrane helps protect the bacteria
  against the defenses of their host
• An outer membrane blocks the entry of drugs

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3 Labs

• Colony characteristics
• Simple and gram staining
• Streak plates for next week
• YOU NEED TO ANSWER LAB QUESTIONS FOR HOMEWORK!!!!

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Lab Questions

• What is the name of the cell type that all
  bacteria are?
• What are the characteristics of that cell type?
• What colony characteristics do you see on your
  petri dish (if yours does not show any growth,
  look at another dish)?
• Is your bacteria gram positive or gram negative?
• What does this show about your bacteria?
• 6. Why is it important to study microbiology?