The Amazing World of Bacteria

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The Amazing World of Bacteria
Bacteria on the point of a pin!!!
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Differences Between Bacteria and Viruses

• Bacteria are classified as living
• Bacteria are prokaryotic cells
• No Nucleus
• Bacteria can perform metabolic functions
• Replication
• Protein Synthesis
• Use and obtain own energy in various ways
• Move on their own

Viruses are not affected by antibiotics
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KINGDOMS 1 2The Prokaryotes

• Eubacteria Archaebacteria
• 1st life forms
• Ubiquitous
• What does this mean?
• Most are helpful, some are harmful
• Can you give an example of each?

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KINGDOMS 1 2The Prokaryotes

• Prokaryotic
• Single celled
• No nucleus
• No membrane-bound organelles
• Bacteria are grown in the lab colonies

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Kingdom 1

• Archaebacteria
• archae Greek "ANCIENT
• Modern archaebacteria MAY BE directly descended
  from (and are very similar to) the first
  organisms on Earth
• Biochemical genetic properties differ from ALL
  other kinds of life
• UNICELLULAR PROKARYOTES
• Cell wall made of pseudopeptidoglycan
• No distinct nucleus with membrane around it
• Most are heterotrophic, a few are autotrophic
• Live in harsh environments
• Sulfurous hot springs, very salty lakes, and in
  ANAEROBIC environments, such as the intestines of
  mammals
• 3 phyla
• Methanogens
• Halophiles
• Thermoacidophiles

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Kingdoms 2

• Eubacteria
• EU "TRUE
• UNICELLULAR PROKARYOTES
• No distinct nucleus with membrane around it
• Cell wall made from peptidoglycan
• Some are heterotrophic, some are autotrophic,
  some are chemotrophic
• Examples
• Most of the Bacteria (Germs) that affect your
  life
• Includes the disease-causing bacteria such as
  tooth decay or food poisoning
• E. coli, Salmonella, Streptococcus

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Typical Prokaryotic Structure
Can move using Flagella Slime Capsule Brownian
Movement
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Bacterial Structure

• Some other important structures
• Plasmids
• Small, circular pieces of DNA
• Separate from the chromosome
• Pillus (pilli)
• Long, rigid, projection used in attachment or DNA
  exchange

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Bacteria Shapes Names

• Bacteria come in several shapes
• 3 main shapes are
• Sphere
• Rod (bacillus)
• Spiral
• The shape may determine the GENUS/GROUP name
• Whats the name of the spherical bacteria?

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3 shapes of bacteria
Cocci
Bacillus
Spirillum
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Shape names...plural vs. singular

• Round
• Coccus (cocci)
• Rod
• Bacillus (bacilli)
• Spiral
• Spirillum (spirilla
• or spirillia)

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Bacterial Arrangement Naming
Pairs Diplo-
Chains Strepto-
Clusters Staphylo-
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What kinds of Bacteria are these?
A
B
C
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Kingdom Eubacteria

• Very strong cell walls
• Made of peptioglycan
• Less complex genetic make-up than ancient
  bacteria
• A. Coccoid single cells.
• B. Rod or bacillus.
• C. Spirilla or spirilloid.
• D. Coccoid filamentous streptococcus.
• E. Coccoid colonial staphylococcus. F.
  Flagellate spirilloid procaryote.
• G-I Examples of Cyanobacteria or "blue-green
  algae"

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What about these?
A
B
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Identifying Bacteria

• 1st level of identification
• GRAM STAIN gram positive purple peptidoglycan
  Easily TREATABLE!!!
• A staining technique that will stain bacteria in
  2 different ways
• Gram () stain purple
• Gram (-) stain pink

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Mix of Gram() and (-) Bacteria
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Bacterial Growth conditions

• Moist
• Warm
• Nutrient Rich
• Some like O2, some hate it
• Obligate aerobe
• Obligate anaerobe

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Bacterial Survival

• When conditions are unfavorable, many bacteria
  can form endospores
• Tough outer coating to resist extreme conditions
• They can survive boiling
• To kill them items must sterilized in an
  autoclave
• Uses pressure heat to kill bacteria spores!
• Ex Clostridium botulinum forms into spores
  (which give off toxins) and is a major concern to
  the canned food industry

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Figure 27.10x Endospores
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Bacteria Reproduction

• ASEXUAL
• Binary Fission
• New organism from one parent
• Not much variety in offspring

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Bacteria Reproduction

• SEXUAL
• CONJUGATION
• Transfer of genes from one bacterial cell to
  another
• Occurs through a pilus

conjugation
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Bacterial Modes of Nutrition Very Diverse

• Nutrition of prokaryotes how org obtains energy
  and a carbon source to build org molecules
• Are 4 categories
• 1. photoautotrophs use light to make food
• 2. chemoautotrophs need CO2 as carbon source,
  and get chemical energy from inorganic substances
• 3. photoheterotrophs use light to make
  energy, but need a carbon source to start with
• 4. chemoheterotrophs must eat other
  organisms to get food in chemical form (most
  bacteria are this type saprobes and parasites)

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Ecological Impact of Prokaryotes

• Recycling of nutrients (decomposers)
• Symbiotic relationships interact with other
  orgs and form food webs
• Bioremediation use or orgs to remove pollutants
  from water, air, and soil
• Ex. Sewage treatment plants anaerobic prok
• Ex. Decompose petroleum compounds at oil spills
  -- pseudomonads
• Act as metabolic factories for human use
• -produce acetone, butanol
• -make vitamins, antibiotics
• -food flavorings (yogurt, cheese)
• -DNA technology produce hormones like insulin

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Nitrogen Fixation

• All organisms need nitrogen (DNA, RNA, ATP, etc)
• Most organisms cant use N2 from the air it
  needs to be in a usable form Nitrogen Fixation
• Some bacteria convert N2 from the air/soil waste
  into a usable form for plants

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Bacteria are often used to fight other organisms
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What are other bacterial uses?
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Pathogenic Bacteria

• Pathogenic Causes disease
• Only 1 of the bacteria we know are pathogenic
• Your body will respond by making antibodies
• Antibiotics can be given to help kill them too!
• They USUALLY target bacterial cell walls break
  them down or disrupt metabolism

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Kochs Postulates 19th Century

• 1. A specific organism must be always be observed
  in association with the disease.
• 2. The organism must be isolated from an infected
  host and grown in pure culture in the laboratory.
  
• 3. When organisms from the pure culture are
  inoculated into a susceptible host organism, it
  must cause the disease.
• 4. The infectious organism must be re-isolated
  from the diseased organism and grown in pure
  culture.

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Bacterial Infection Symptoms

• Physical damage by product of bacteria
  digesting your tissue Streptococcus pyogenes
• Endotoxins Listeria monocytogenes
• Exotoxins Clostridium botulinum antibodies
  may work but may be overpowered
• Immune reaction to foreign invaders

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Bacterial Diseases Modes of Transmission
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Preventing bacterial infection

• Sterilization of surfaces (with antiseptics,
  heat, or steam)
• Cooling, freezing food
• Dehydrating food (salt curing)
• Use chemical preservatives (food or water
  chlorine)
• Radiation
• Pasteurization (heating liquids)
• Canning
• Washing hands!!!
• Antibiotics are used only AFTER have infection
  present

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Antibodies vs. Antibiotics vs. Antiseptics

• Antibodies produced by white blood cells in the
  body (internal line of defense)
• Antibiotics kill bacteria using chemicals that
  are produced OUTSIDE of the body by other sources
  then
• introduced IN TO body as injection or ON TO
  site of infection as surface medication

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• Antiseptics Kill bacteria on OUTSIDE of body or
  on membranes that line areas leading to inside
  (ex. Mouth)
• Ex. Alcohol
• Listerine
• Iodine
• Hydrogen Peroxide
• Disinfectants act as surface antiseptics for
  non-living surfaces before bacteria even get to
  body
• Ex. Chlorox
• Lysol
• Ammonia