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Ch 27: The Prokaryotes Bacteria & Archaea

(Eubacteria & Archaebacteria)

Some phyla

Epulopiscium

Paramecium

2nd largest bacterium known

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Largest known bacterium:

Thiomargarita namibiense

Bacterial cell structure

coccus/cocci bacillus/bacilli spiral

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PHA inclusions

Bacterial cell walls

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slime layer

conjugation pilus (pili pl.)

Motility

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Axial filaments (spirochaetes only)

Slime jets

Grappling hooks Bacteria: Type IV pilus/pili Archaea: hamus/hami

Motility

DNA

Nutritional Modes Energy source

phototroph vs. chemotroph

for phototrophs (lots of variation): group PS pigments(s) 1) purple S bacteriochlorophylls a or b 2) purple non-S bacteriochlorophylls a or b 3) green S bacteriochlorophylls a + c, d, or e 4) green non-S bacteriochlorophylls a + c 5) Halobacterium bacteriorhodopsin* 6) cyanobacteria chlorophyll a + phycobilins 7) PS-protists chlorophyll a + various 8) almost all land plants chlorophyll a + b

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Nutritional Modes (cont.)

C source:

autotroph vs. heterotroph

Combinations

chemoheterotroph

chemoautotroph

photoheterotroph

photoautotroph

Oxygen (O2) use aerobe vs. anaerobe

Modifiers

facultative vs. obligate Ecologically - very important; 2 examples

recycling symbioses (mutualism, parasitism, commensalism)

Human Microbiota: new perspective

“No tissue in the human body is sterile, including reproductive tissues and, for that matter, the unborn child,” Seth Bordenstein, a biologist at Vanderbilt University, says in an e-mail to The Scientist. 8/14

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proteins lipopolysaccharides

DNA-based

Aquifex

Old lineage?

thermophiles & hyperthermophiles

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Deinococcus radiodurans

TEM Thermus aquaticus = “Taq”

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Cyanobacteria =

blue-green bacteria (chl a & phycobilins:

phycoerythrin & phycocyanin)

Gloeocapsa Spirulina

Azolla (fern) & Anabaena (cyanobacterium) symbiosis

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Alpha Proteobacteria

Agrobacterium also:

Rickettsia rickettsia

mitochondria Rhodobacter (purple non-S)

Most numerous bacteria on earth: Wolbachia spp. (affect their host’s reproduction)

insect egg

mitochondria

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Beta Proteobacteria

Neisseria gonorrhoeae

Neisseria meningitidis

Rubrivivax

Gamma Proteobacteria

Vibrio cholerae

Escherichia coli

Legionella

Salmonella typhi also Shigella

Delta Proteobacteria

Myxobacteria

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Epsilon Proteobacteria

Campylobacter Nobel Prize Med. 2005

P: Chlamydiae

Chlamydia trachomatis

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Spirochaetes

Borrelia burdorferi

Treponema denticola

Bacteroides thetaiotamicron

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Firmicutes

Firmicutes: Clostridium

Clostridium tetani

Clostridium perfringens Clostridium difficile

Clostridium botulinum

Bacilli Lactobacilli

Bacillus

Lactobacillus

Streptococcus Staphylococcus

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P: Tenericutes = mycoplasmas (recently separated from Firmicutes)

Mycoplasma pneumoniae

Actinobacteria

Actinobacteria = actinomycetes (aka High G+C Gram +’s)

Mycobacterium tuberculosis

M. leprae

And Bifidobacterium

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Archaea

Geogemma (strain 121)

Sulfolobus

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Methanobacterium

Picrophilus

Halobacterium

Owens Lake

Known only from environmental samples

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New Phylum: Nanoarchaeota: some of smallest cells known (“nano” = 1/billionth -> implies “very small”

From the report in Nature (5/2/02): Found “on the surface of an Archaean called Ignicoccus (green), whose cells are about 2 millionths of a metre (2 µm) across. Each cell sported 30 to 50 Nanoarcheum equitans cells” (red).

“The organisms are about 400 billionths of a metre (0.4 µm) across - more than six million would fit on the head of a pin.”