Prokaryotic Diversity- Archaea

Question 1

How many phyla are archaea split into?

Answer 1

5

Question 2

True or False: Breadth of phylogenetic diversity is similar to that of the Bacteria and Eukarya.

Answer 2

True

Question 3

Which Archaeal phylum includes Haloarchaea, also known as Halobacteria?

Answer 3

Euryarchaeota

Question 4

What is an example of Euryarchaeota Haloarchaea? What is a requirement for this archaea?

Answer 4

Halobacterium salinarum-
Absolute requirement for high salt concentrations
Typically need at least 1.5 M (~9%) NaCl for growth Found in solar salt evaporation ponds and salt lakes where the salt concentration approaches saturation
Ex) Great Salt Lake (Utah), Dead Sea
Ex) soda lakes (highly alkaline

Question 5

How do Euryarchaeota Haloarchaea maintain osmotic balance in a highly ionic environment? Give an example.

Answer 5

The archaea synthesize or accumulate compatible solutes. Halobacterium salinarum pumps large amounts of K+ into the cell from the environment.

• Intracellular K+ concentration exceeds extracellular Na+ concentration
• Water flows into the cell in hypersaline environments

Question 6

Some Euryarchaeota Haloarchaea have a unique system for generating energy: Light-driven synthesis of ATP without the use of chlorophylls. What pigment do they use instead?

Answer 6

Bacteriorhodopsin

Question 7

What is Bacteriorhodopsin?

Answer 7

Integral membrane protein  
Absorbs light energy and pumps protons across the membrane to make a PMF  
PMF is used to generate ATP 
They do not fix CO2 
Ex) Photoheterotrophy

Question 8

Euryarchaeota also include Methanogenic Archaea. What is special about them?

Answer 8

Only microbes capable of significant methane production (Methanogens).

Question 9

What is an example of an Euryarchaeota Methanogen?

Answer 9

Methanobacterium
4H2 + CO2 -> CH4 + 2 H2O
-chemical formula for how the methane is produced
-better than fermentation
Produce the bulk of CH4 in the atmosphere
Important green house gas
Strict anaerobes, found in many diverse anaerobic environments
Ex) Cow’s gut; Sewage sludge

Question 10

Euryarchaeota Methanogens demonstrate the diversity of cell wall chemistries. What is an example?

Answer 10

Pseudomurein used in Methanobacterium

• Similar in structure to peptidoglycan
• Less similar in composition to peptidoglycan

Question 11

Which family of Methanobacterium are the only ones to have the Pseudomurein composed cell wall?

Answer 11

Methanobacteriales family

Question 12

Not including Methanobacteriales, what kind of cell wall do most other Methanogens usually have?

Answer 12

Most other types of methanogens have a S-layer made of protein or glycoprotein as their cell wall.

Question 13

Which Archaeal phylum achieves nitrification?

Answer 13

Thaumarchaeota

Question 14

What is an example of Thaumarchaeota? What does it create in its environment?

Answer 14

Nitrosopumilus maritimus-
Aerobic, ammonia oxidizing chemolithoautotroph:
-Converts NH3 into NO2- for energy
-Uses CO2 for carbon
-Abundant in open ocean water where they seem to be a major player in nitrogen cycling
It creates a very complex ecosystem in the world around it.

Question 15

What is an example of the Archaeal phylum Nanoarchaeota?

Answer 15

Nanoarchaeum equitans-
One of the smallest cellular organisms (~0.4 µm) Obligate parasite of the crenarchaeote Ignicoccus
-Contains one of the smallest genomes known
Lacks genes for all but core molecular processes
Depends upon host for most of its cellular needs

Question 16

What is an example of the Archaeal phylum Korarchaeota?

Answer 16

Korarchaeum cryptofilum-
Obligately anaerobic chemoorganotroph
Hyperthermophile
Cells are long, thin filaments
Lacks many core genes
Depends on other members of hot springs community and cannot yet be grown in pure culture
-because we do not know what growth factors his family gives him

Question 17

What Archaeal phylum are mostly hyperthermophiles?

Answer 17

Crenarchaeota

Question 18

Where are Crenarchaeota found?

Answer 18

Found in extremely hot environments:

• Boiling hot springs, deep ocean vents
• Other representatives are found in extremely cold environments

Question 19

True or False: Crenarchaeota can be either chemoorganotrophs or chemolithotrophs. Most will use sulpher in their metabolism.

Answer 19

True

Question 20

What is an example of Crenarchaeota?

Answer 20

Sulfolobus acidocaldarius-
Grows in sulfur-rich acidic hot springs (~90°C, pH 2) Hyperthermophile and acidophile
Aerobic chemolithotroph that oxidizes reduced sulfur or iron
Example: 2S^0 + 3O2 + 2H2O 2 H2SO4
*2S^0 intermediate reduction of H2S

Question 21

What Archaeal SUPERphylum is Only known from sequence analyses from metagenomes. Ecological functions are unknown.

Answer 21

Asgard Superphylum

Question 22

What interferes with the sequencing of the Superphylum Asgard?

Answer 22

Their metabolism

Question 23

Due to their similarity what do people think the sequence of the superphylum Asgard may be?

Answer 23

The ‘missing link’ between Eukarya and Archaea.

Question 24

True or False: Members of this superphylum contain versions of genes previously thought to have been prokaryotic-specific

Answer 24

False: Members of this superphylum contain versions of genes previously thought to have been Eukaryotic-specific.

Question 25

Which Norse Gods are the superphylum Asgard’s phyla broken down to?

Answer 25

Lokiarchaeota, Odinarchaeota, Thorarchaeota etc