Chemolithotrophic proteobacteria S and Iron oxidizing

• (SCIENCE 284: 16 April 1999) Thiomargarita namibiensis

• Beggiatoa (Winogradsky column)• Thiothrix/Thioplaca• Thiobacillus• endosymbionts of deep-sea vent

invertebrates

Quiz

1. Why is 16S rRNA such a good molecule for making phylogenetic trees (give 2 good reasons).

(3)2. What is the evolutionary distance between these two

sequences. You may define it as a %.GGCCCTATATAC

GCGCCTTTATAC (2)3. Chloroplasts were originally _______, and are proof for

theory of ________ (2)4. Name three different ways to define a bacterial species

(3)

Nitrifiers

• Nitrosonomas and Nitrobacter

• Winogradsky

Hydrogen oxidizers

• Alcaligenes ”Knallgas reaction“

• 2 H2 + O2 ---- 2 H2O

Methanotrophs and Methylotrophs

• Not all methylotrophs are methanotrophs• Use methanol, methylamine, formate and

(methane)• Type 1 (ribulose monophosphate pathway) and II

(serine pathway), membranes differ too– Type 1 membranes are throughout cell

– Type II on periphery of cell

• Endosymbionts in deep-sea vent mussels

Photosynthetic proteobacteria

• Purple phototrophic proteobacteria (bacteriochlorophylls and photophosphorylation)

• Purple sulfur, eg. Chromatium

• Below is Chromatium tempedium from Yellowstone, that grows above 50C. Notice the phase-bright sulfur granules

• Purple non-sulfur (photoheterotrophs)

• (other groups in the Bacteria that photosynthesize?, green sulfur, green filamentous, cyanobacteria)

Spirilla:

• Spirillum _some magnetotactic e.g. Magnetospirillum p 487

• Bdellovibrio, attack gram – bacteria, see developmental cycle

Sulfate/sulfur reducers

• Desulfurovibrio, Desulfuromonoas, anoxic habitats, compete with methanogens

• use, H2, lactate as e'donors and sulfate or sulfur as e'acceptor. What is the product?

Budding and stalked

• Hyphomicrobium (methylotroph), budding

• Caulobacter, stalked, see cycle

Sheathed Proteobacteria:

• e.g Leptothrix• Mn 2+ + 0.5 O2 + H2O --- Mn O2 + 2H+ delta G –68kJ

Fermentative rods and vibrios 1.Enterics (gamma)

• Gram -, nonsporulating, facultative aerobes, fermentative, opportunistic pathogens

• 2 types: mixed acid fermenters (produce acid) E. coli

OR 2,3-butanediol fermenters (produce neutral products) Enterobacter aerogenes/Erwinia

Escherichia

Salmonella typhi- typhoid fever Serratia marcescens (Bright red pigment- prodigiosin) Xenorhabdus (bioluminescence) Klebsiella pneumoniae (not normally pathogenic)

Vibrio, Photobacterium

• V. cholerae

• Photobacterium– O2 required for luciferase activity– Quorum sensing

– FMNH2 + O2 +RCHO ---- FMN +RCOOH + H2O + hv

– Need flavin mononucleotide, aliphatic aldehyde, O2, and enzyme. E- donor is NADH

Oxidative rods and cocci• Pseudomonads (human pathogens, biodegraders, plant

pathogens)• Azotobacter and free-living N-fixers• Rhizobium and Bradyrhizobium: symbiotic N-fixers• Agrobacterium, crown gall• Acetobacter and Gluconobacter• Legionella, • Neisseria• Rickettsia obligate parasite, Rocky mountain spotted

fever