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					Bacteria
Characteristics of LUCA (last universal common ancestor)



Members of all the domains:
• Conduct glycolysis
• Replicate DNA conservatively
• Have DNA that encodes peptides
• Produce peptides by transcription and
  translation using the same genetic
  code
• Have plasma membranes and
  ribosomes
Structure:


Procaryotic.)




Prokaryotic cells differ from eukaryotic cells.
Prokaryotes lack a cytoskeleton; divide by
   binary fission.
DNA is not in a membrane-enclosed nucleus.
   DNA is a single, circular molecule.
Prokaryotes have no membrane-enclosed
   organelles.
Cell wall; unique and varied




 Gram positive                  gram negative


Lipid bilayer inside( porous)              lipid bilayer, glycoprotein
Glycoprotein outside             outer lipopolysaccharide (impervious)
                                  many resistant to antibiotics.
Reproduction: can divide, and can come together and
share some genetic information.
Sex is bacteria – haploid
(one set of information)
ring dna – one dna strand
only
Classic view; identified by morphology;
Bacillus anthracis; rod shaped
Spirillum : spiral shaped
Merismopedia: cocci.round, and here colonial
Nostoc, cyanobacteria.; photosynthetic
New view: based on biochemistry.
Recognition of tremendous variety in
metabolic systems
                 energy   carbon
                 source   source
Photoautotroph   light    CO2
Photoheterotroph light     organic C
Chemolithotroph inorg.    CO2
Chemoheterotroph org. C     org C
  both live and dead source of energy
Corresponds to plant, animal, fungi

 Also, some are aerobes, some
 anaerobes, some can do both.
Distances represent
biochemical diversity;


Note all eucayotes beyond
protozoa are very close!

 Homo = Human
 =all animals
 Coprinus =
 mushroom
 Zea = corn, all
 higher plants
 Parmecium =
 eucaryotic protist
 Porphyra = red
 algae
 Costaria = brown
 algae
Lateral gene transfer and
domains


Why are the three domains oddly
different yet similar?
 LETTER Nature Genetics 29, 54 - 56 (2001)
Published online: 13 August 2001; | doi:10.1038/ng708
Comparable system-level organization of Archaea and Eukaryotes
J. Podani1, 2, Z.N. Oltvai1, 3, H. Jeong4, B. Tombor3, A.-L. Barabási1, 4 & E. Szathmáry1, 2
1



                                                                  Figure 1. Analyses based on
                                                                  information transfer
                                                                  pathways.
                                                                  a−d, NMDS ordinations. e,g,
                                                                  OC classifications. f,h,
                                                                  UPGMA classifications. i,j,
                                                                  unrooted NJ trees. (a,b,e,f,i)
                                                                  represent data based on
                                                                  substrate list;(c,d,g,h,j) are
                                                                  based on enzyme variables.
                                                                  (a,c,e,g) represent ordinal
                                                                  information; (b,d,f,h,i,j)
                                                                  represent P/A information. A,
                                                                  Archaea; B, Bacteria; E,
                                                                  Eukarya.
Figure 2. Analyses based on
metabolic pathways.
a−d, NMDS ordinations. e,g,
OC. f,h, UPGMA classifications.
i,j, unrooted NJ trees. (a,b,e,f,i)
represent data based on
substrate list; (c,d,g,h,j) are
based on enzyme variables.
(a,c,e,g) represent ordinal
information; (b,d,f,h,i,j) represent
P/A information. A, Archaea; B,
Bacteria; B1, nonparasitic
bacteria; B2, parasitic bacteria;
E, Eukarya. The arrow in (f)
indicates the location of the
Crenarchae A. pernix.
Possibility of lateral gene transfer between
species.



Importance: movement of genes from one
species to another = gm crops?
• Prokaryotes are the most successful organisms
  on Earth in terms of number of individuals.
• The number of prokaryotes in the ocean is
  perhaps 100 million times as great as the
  number of stars in the visible universe.
• They are found in every type of habitat on Earth.
• Every procaryote is infected by viruses, so a lot
  more viruses than anything else.
Importance of bacteria.


1. Ocean plankton – photosynthetic - add Iron – reduce C02 in
   atmosphere
2. Nitrogen fixation – N2 – usable forms
3. Decay – breakdown of organic molecules
4. Fermentation – the glory of wine and beer
5. Environmental cleanup – archaea.
6. Disease issues
         infertility – Chlamidia
         atherosclerosis – arterial plaque
         kidney stones
         stomach ulcers – heliobacter (Barry Marshall)
         cystic fibrosis – protection against typhoid


7. Bird flu – why worry?
8. Influenza – why will we never eliminate it.
9. When should a bacteria (disease) kill quickly? When slow?
10. Antibiotic resistance
Dental Plaque = colony of bacteria in a biofilm.
Purification of water supply
1. Typhoid – recognition of tainted water transmission


2. What is clean water? Amount of fecal bacteria.
3. Sewage treatment
4. Water treatment – improvement with time until today.
5. Where is the water supply safest and why?
Classic issue of
Bad water and
disease. London
1854
Solutions ; Sewage Treatment
0. put sewage somewhere else (Chicago solution)
1. Primary treatment – get rid of solids
  what to do with them?
2. Secondary treatment – bacterial digestion – leaves nutrients
    reclaimed water for golf courses
3. Tertiary treatment – chemical carbon filter, electrolytes
   What to do with the water?


Costs: primary - $.05 per 1000 gallon
       secondary$.10 per “         “
       tertiary   $.50 per 1000 gallons
The reason Clean Water Act only went to Secondary treatment.
        Problems with water
• Non-point sources of pollution
     dogs, cats, etc.



 high nutrients = algal growth leads to
 bacterial growth
         How to purify water
• 1872 – filter through sand
• 1896 – chlorination, chlorine gas now we
  use ozone, other oxidants
• Today – aerate, chlorinate, settle, filter,
  rechlorinate, etc.
  The explanation for ‘swimmer’s or surfer’s ear




Question: who has the purest water, Los Angeles or Aspen, Colorado??

				
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posted:8/16/2011
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