Eubacteria

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Eubacteria
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Bacteria Kingdom Eubacteria

• Oldest, most abundant and diverse group of living
  organisms

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Characteristics

• Single cell
• Prokaryotic
• Single chromosome
• No membrane bound organelles
• Reproduce sexually and asexually

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Structure

• Capsule ? protect against
• WBC, cling to surface,
• protect from drying out
• Cell wall ?maintain shape
• Nucleoid ? circular mass of
• DNA
• Plasmid ? single circular DNA
• strand used in
  conjugation
• Pili ? attachment to host cell
• Flagellum ? motion (whip)
• Ribosomes ? make protein

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How big are bacteria?
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Classification

• Based on
• Shape
• Arrangement
• Cell wall structure
• Carbon and energy source
• Oxygen requirements

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Shape

• Spherical
• Cocci (pl)
• Cocus (sing)
• Rod shaped
• Bacilli (pl)
• Bacillus (sing)
• Spiral
• Spirilla (pl)
• Spirillum (sing)

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Arrangement

• Prefix
• Diplo twos
• Staphylo cluster
• Strepto ? chains
• Sarcina ? octets
• Tetrad ? fours

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Cell wall structure

• Peptidoglycan
• Thin sheet composed of 2 sugar derivatives and a
  small group of amino acids that make up the cell
  wall
• Formation is disrupted by penicillin

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Gram Positive vs. Gram Negative

• Gram Positive
• Thick protein layer on cell wall
• Stain deep purple
• 90 of wall is made of peptidoglycan
• Gram Negative
• Thin protein layer on cell wall
• 5-20 made of peptidoglycan (penicillin is not as
  effective)
• Stain pink
• Lipopolysaccharide layer on outside of cell wall
  acts as a permeability barrier

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Gram Positive vs. Gram Negative
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Carbon and Energy Source
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Oxygen Requirements

• Obligate Aerobes
• require O2 for survival
• e.g. pneumonia, tuberculosis
• Obligate Anaerobes
• O2 not required for survival
• e.g. food poisoning, tetanus bacteria
• Facultative aerobes
• mainly function in the absence of oxygen can
  function in the presence of O2
• Facultative anaerobes
• grow best in presence of oxygen can function in
  absence
• e.g. scarlet fever, typhoid fever, E. coli in
  human intestines

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Reproduction in Bacteria

• Binary Fission ? asexual reproduction
• Conjugation ? sexual reproduction

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Binary Fission - Video
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Conjugation - Video
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Bacterial Growth

• Exponential Growth
• Limited by the exhaustion of nutrients or
  accumulation of toxic products

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Comparing Eubacteria Archaebacteria

• Similarities
• Prokaryotic single celled
• No membrane bound organelles
• Single chromosome
• Reproduce asexually by binary fission

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DIFFERENCES

• Eubacteria
• Cannot tolerate high temp
• Aerobic/anaerobic

• Archaebacteria
• Found in swamps, high salt concentration, high
  temp., high acidity
• Anaerobic (most)

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How are bacteria similar to and difference from
viruses?

• Similar ? have genetic material,
• pathogenic (some)
• Different ? bacteria are capable of
• independent life

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• Eubacteria and archaebacteria reproduce using
  binary fission.

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How is this process different from mitosis?

• Much simpler, only single strand of DNA is
  replicated ? no lining up along equator, spindle
  fibers, etc.

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Explain how bacteria share genetic information

• Conjugation
• make contact with cytoplasmic bridge (pillus)
• Plasmids are transferred from the donor to the
  recipient

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Describe two beneficial effects of bacteria and
two harmful effects of bacteria. Include
examples

• Beneficial
• 1. Flavobacterium
• dismantle complex penta molecules, leaving
  non-toxic CO2 H2O and harmless chlorides.
• 2. Streptomyces source of antibiotics

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• Harmful
• legionella pneumophilia
• Legionnaires disease
• 2. E.coli 157 in Walkerton

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What is an antibiotic?

• chemicals produced synthetically or by
  microorganisms that inhibit the growth of or
  destroy certain other microorganisms

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How does bacterial resistance to antibiotics
develop?

• Resistance
• ? genetic variation allows some to survive
• ? pass on R (resistance) factor to next
• generation as well as through
• conjugation
• ? R factor increases population