Bacteria

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

Characteristics of LUCA (last universal common ancestor)

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.

Gram positive gram negative

Lipid bilayer inside( porous) lipid bilayer, glycoprotein

Glycoprotein outside outer lipopolysaccharide (impervious)

many resistant to antibiotics.

Cell wall; unique and varied

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?

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.

LETTER Nature Genetics  29, 54 - 56 (2001) Published online: 13 August 2001; | doi:10.1038/ng708 Comparable system-level organization of Archaea and EukaryotesJ. Podani1, 2, Z.N. Oltvai1, 3, H. Jeong4, B. Tombor3, A.-L. Barabási1, 4 & E. Szathmáry1, 2 1

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??