The Wonderful World of Bacteria

1
The Good, Bad, and the Ugly

• The Wonderful World of Bacteria

2/11/11
2
Facts-Why should we care ?

• we share
• our world with them!
• our guts with them!
• normal flora
• human Gut motel

3
the Good

• hand full - soil billions of bacteria
• Recycle nutrients -
• eg nitrogen cycle N2 to NH3 to nitrates, to
  nitrites
• plants can use nitrogen in this form.
• bioremediation - clean up pollutants ?
• contaminated waste sites -
• convert poisonous toxins to harmless molecules
• bacteria fungi do this.
• sewage treatment - breaks up - solid wastes-
• easy recycling
• Control harmful organisms living within us.-by
  controlling their nutrients

4
The Good bacteria- continued.

• Decomposers -
• dead organisms - break down flesh- release
  nutrients
• nutrients from dead are freed up
• Lacy Peterson -
• Antibiotics -
• are produced by bacteria
• to inhibit competing bacteria - competing for
  food.
• bacteria are ideal factories - churning out
  chemicals.
• reproduce like rabbits!!

5
The Good bacteria- continued.

• Genetic engineering -
• We can cut splice genes (DNA) - together into
  new combinations.
• different organisms made - by fused genes.
• these new recombinations -multiplied in quantity
  by bacteria
• eg. also vaccines, HGH, insulin,

6
Useful bacteria

• Food that we eat-
• lactobacillus (lactic acid bacteria)
• pickles, yogurt, olives, sauerkraut, cheese,
  fermented meats - salami, vinegar, soy sauce,
  chocolate,
• B vitamins, citric acid (candy and soft drinks

7
Research Technology

• Decomposers - yea!
• Sewage treatment Methanogens
• Can decompose pesticides petroleum products -
• Pseudomonads
• Can produce chemicals - in huge vats
• eg acetone, butanol,
• Pharmaceuticals
• Can create vitamins antibiotics,
• are even bacteria containing magnetic particles
• maybe a commercial source for -magnetic tapes
  recording devices.

8
The Bad

• Food spoilage
• milk-
• salmonella - food poisoning
• runny eggs - not fully cooked.
• tetanus - caused by a toxin
• deep puncture
• lockjaw - affects muscles and nerves
• Food poisoning - eg Mexico
• unfamiliar local bacteria
• Montezumas revenge travelers diarrhea!

9
The Ugly

• Diseases
• TB - tuberculosis -
• slowly takes hold (lungs), unnoticed
• penetrates cells of immune system.
• tissues die, dead tissue serves as food for
  bacteria.
• Strep throat -Streptococcus pneumoniae
• exist in our moist throats -
• Usually well behaved, until were weakened by
  cold or flu
• pneumonia-
• e coli
• Botulism
• botox commercial product - paralyzes muscles

10
Bacteria-what are they?
1

• are single celled organisms simple
• 1/100th size of human cell (1 micrometer long)
• 3.5 billion years old!
• are Prokaryotic Cells
• no nucleus no nuclear membrane
• No organelles no nucleus,
• no mitochondria, no ER, no Golgi, etc.
• In Cytoplasm is nucleoid region no separation
• no compartments just a big vat
• like a large hall, multiple classrooms
• plasma membrane w/inward folds
• enzymes may be located in folds.

11
Size ?
1/100th size of human cell (1 micrometer long)
head of pin
12
Structure

• Cell wall structure protection
• Plasma membrane -
• transport - materials in out
• Surface receptor markers -
• receive of extracellular signals.
• 1 large loop of DNA - genome
• plus multiple plasmids - circles of DNA
• Some, which carry genes for antibiotic resistance
• plasmids can be copied passed to other bacteria
  as close to sexual transmission as we can get
  here.
• Ribosomes - protein workbench

13
Structure
14
Shapes - 3 main ones

• Sphere - Cocci (kahk-sie)
• Streptococci (Strep-tuh-Kahk-sie)-
• chains-oooooooooooooooooooooooooo
• Staphlococci (Staf-uh-loh-Kahk-sie)
• Grapelike clusters
• Rod -bacilli (buh-SIL-ie)
• helix -spiral -Spirochete

15
Movement

• Flagella - whip like
• Propeller -
• Towards vs away
• or use slime - glide along cells surface

16
Pili

• Pili - acts like velcro
• and when partnered with slime capsule.
• used to attach to others, and objects
  Stickiness -
• biofilm on back of tongue
• Cutting boards
• plaque on teeth
• lining of instrument, tubes hospital, dentist
  office.

17
Reproduction -1 of 9 LA

• Reproduce quickly - asexual fission
• fastest 1 divides into 2 separate bacteria
  approx. once every 20-30 minutes.
• 99.5 are identical clones !! ??
• At this rate1 bacteria millions in 24 hours
• TB (slow) - 1 division every 16 hours
• Conjugation - do not reproduce sexually
• No fusion of 2 gametes.
• they can copy and transfer plasmids to other
  bacteria, even other strains !!
• can transfer antibiotic resistant genes !

18
What if ? facing harsh conditions ?

• can create sleeping cells endospores
• slime capsule- (some bacteria) -
• Enables them to stick to -rocks, host cells, etc.
• Holds water in - protects from dryness?
• Protects them vs phagocytes (which engulf)
• Protects vs bacteriophages
• eg botulism spores-
• How to kill toxins endospores?
• must boil at 120 degrees C (280 degrees F)
• some can withstand an hour in boiling water

19
Nutrition growth

• Autotrophic- energy from sun or minerals
• heterotrophic-energy from organic matter.
• saprophytes -feed on dead and decaying
• obligate (Ahb-luh-git) anaerobes-
• cant survive in oxygen.
• obligate aerobes -
• need oxygen to survive

20
How do they cause disease

• Some penetrate host cell membrane, destroy host
  cells -
• feed off of host cells use digestive enzymes
• Most cause disease w/ TOXINS -
• Poison -damages hosts metabolism.
• ENDOTOXINS
• in plasma membrane of Gram neg (-) Bacteria
• Forms shield against antibiotics
• chills, fever, damage to circulatory sys
• EXOTOXINS-carried in blood
• Eg diptheria, tetanus, botulism
• all different proteins different symptoms
• NEW- Virus (prophage) made 1 strain of diptheria
  virulent.

21
Control of bacteria

• Prevent spread ?
• To prevent airborne bacteria ? - eg. coughing
  sneezing droplets must Quarantine (eg.
  Diptheria, Scarlet fever, whooping cough, TB)
• Vaccination -
• Hygiene sanitation best preventative measure!
• Heating to 60 oC for 30 minutes destroys exotoxin
  proteins kills most bacterial cells.
• Pasteurization - short bursts of high heat!!
• Antibiotics - eg penicillins interfere with cell
  wall synthesis bacteria pop.

22
evolve and adapt?

• MRSA - methicillin resistant staphlococcus aureus
• antibiotic resistant strains have evolved,
  reproduced
• using conjugation to pass resistant genes along.
• our overuse of antibiotics for minor infections
• cause drugs to be ineffective for major bacterial
  illnesses

23
Extreme conditions

• Extreme some.
• live in saturated salt ponds (brine)
• live in hot, sometimes acid springs
• Yellowstone park - 60 degrees C, pH 1-2
• acidic pools - pH 1-2 - same as sulfuric acid.

24
Christian Gram - 1888

• Difference in bacterial cell wall composition -
  critical clinically.
• Gram Staining procedure
• bacterial cell wall not made of cellulose like
  plants.
• gram positive bacteria - retain crystal violet
  stain
• gram negative - cell walls very thick - dont
  retain stain
• Gram pos () or Gram neg (-) can determine which
  antibiotic to use.
• some have a slime capsule - protects against
  phagocytosis (engulfment) by white blood cells.
• eg. Streptococcus pneumoniae

25
bacteria cell walls- gram /-
26
no need of a host -

• Completely Independent organisms
• not like viruses.
• Can eat reproduce on their own!
• Like fish swimming in the ocean of
• your body.
• Like a human swimming through honey.

27
Questions

• What if every dead animal plant was laying out
  in the street ?
• You have atoms in your body that were once part
  of dead organisms, and were recycled by bacteria
  and fungi.

28
Energy ?

• fermentation

29
Your body

• made up of 100 trillion cells
• Each of your cells
• has a Nucleus
• has energy production equipment