Bacteria

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Bacteria

• bacteria by Jonathan Coulton

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Objectives

• Define Bacteria, eubacteria, archaebacteria,
  and note the relationships between them.
• Methods used to classify bacteria
• Describe 3 types of archaebacteria
• Gram-positive vs. Gram-negative bacteria
• Structure of a bacteria cell
• How they move
• Bacterial genetic recombination

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• Its their planet, they were here first, and
  theres more of them than us.
• Theyre microscopic prokaryotes
• No nucleus, ect

The bacteria save us in War of the Worlds
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Evolution

• Theyve been evolving for 3.5 billion years,
  thats a lot of time to turn into different
  species.
• Theyve found ways to survive almost everywhere.
  Some can hibernate in space
• Leads to interesting ideas

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How many?

• 40 million bacteria in a gram of dirt
• 1 million in a mL of fresh water
• 5x1030 bacteria in the world
• Your body has 10xs more bacteria cells than
  human cells in it

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Classification

• A lot of bacteria look pretty much alike
• Group them on
• Structure, physiology, how they react to dif.
  Types of staining techniques
• OR group them on RNA similarity

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Why did the bacteria cross the microscope?

• To get to the other slide.

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Two kinds of bacteria

• Eubacteria
• Archaebacteria
• More ancient group

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Archaebacteria

• Have weird lipids on their membranes
• Have introns in their DNA
• Have NO Peptidoglycan
• A protein/carb mix

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Extremophiles

• Love extremes
• No competition there
• Places to salty, acidic, hot or cold, for life

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Methanogens

• Oxygen kills them
• Live at bottom of swamps, or in sewage
• Can combine O2 and CO2 into methane
• Swamp gas
• And in your gut
• Enteric bacteria
• E. Coli ? a facultative anaerobe It can live
  with or without O2
• Obligate anaerobes Have to live where theres no
  O2

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Halophiles Acidophiles

• Halophiles Love salt
• Live in the dead sea
• 2nd saltiest water on Earth
• 8xs saltier than oceans
• Lowest point on earth not covered by ice
• 418 M below sea level

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Dead Sea

• King David, Herod, Jesus, John The Baptist,
• Jericho is just north (oldest continually
  occupied town
• But the sea is shrinking
• People need water

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Volcanic acid lake in Gorley (Kamchatka, Russia)

• A crowbar will dissolve in about an hour in this
  lake

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Acid Lake in Taal, Phillipines

• Sulfuric vents at the lakes edge

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Eubacteria

• Rod shaped Bacilli
• Sphere shaped cocci
• Linked in a chain streptococci
• Grape-like clusters staphylococci
• Spiral shpaed Spirilla

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Gram Stain

• Gram-positive keep the stain, show up purple
• They have peptidoglycan
• These bacteria make yogurt
• Gram-negative dont take the gram stain, but do
  take a pink stain instead
• Rhizobium makes N2 gases usable by plants
• The difference Make dif, chemicals, react to dif
  antibiotics and disinfectants

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Cyanobacteria

• Not plants, but do photosynthesis
• Heterocysts a kind that makes Nitrogen usable
  for plants
• If you put a lot of nitrogen into a water supply
  you get a population bloom
• Eutrophication all these bacteria suck up the
  oxygen and everything else in the water dies

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Genetic recombination

• Without reproducing bacteria can acquire and
  express new genetic info
• Transformation Bacteria take in DNA around it
• Conjugation Bacteria use pilli to make a bridge
  between each other and uses plasmids
• Transduction viruses carry DNA between bacteria