Test 1 - Myxococcus xanthus Flashcards
Myxococcus xanthus’ walls are Gram +/-
Gram -
What is its organization in terms of flagella? Is it immobile?
No flagella, BUT can move with “gliding motility”
What is Gliding Motility?
Smooth movement of cell on a surface without need for flagella, which creates a slime trail to aid movement.
What two different types of motility are there for Myxococcus xanthus?
- A-Motility (Adventurous)
2. S-Motility (Social)
When does Myxococcus xanthus perform A-Motility?
By single cell, on firm surface.
What protein aids A-Motility? How does it aid motility?
CGLB, which may release surfactants at back of cell. Surfactant disrupts H-bond and hence surface tension of water. Surfactant allows Myxococcus xanthus to move in the opposite direction of the surfactant.
When does Myxococcus xanthus perform S-Motility? What does it require? What does this body part do?
In group. It requires a pillus, which allows the bacteria to grab onto other cells.
T/F: In a colony of Myxococcus xanthus, all cells are performing S-Motility
F. The edges are performing A-motility.
Is it an aerobe or an anaerobe? What metabolism does it perform?
Aerobe. No fermentation.
It is a (chemo/photo)(heterotroph/autotroph)
Chemoheterotroph.
Where do Myxococcus xanthus get their food from?
Microorganism/fungi and dead organisms.
How is Myxococcus xanthus like Bacillus anthracis?
They both secrete digestive protein, which lyse cells in contact. It also take up peptides from organisms to use for energy and source of molecules.
What do Myxococcus xanthus secrete to hunt? Why? (2)
- Digestive proteins to lyse cells
2. Antibiotics to disturb enzyme
How does Myxococcus xanthus’ hunting habit fit into its behavior? (2)
Because it hunts in packs, it
- Uses S-Motility to swarm prey, and
- Constantly secrete digestive enzymes for more effective killig.
Does Myxoccocus xanthus grow? How?
Yes, by elongation.
Does Myxoccocus xanthus develop? How?
Forms spores (NOT ENDOSPORES) when triggered by stress (- nutrient)
What are the 3 steps of Myxococcus xanthus development into spores?
- Sense starvation
- Form aggregate
- Differentiate
What happens in step 1 of Myxococcus xanthus development into spores? What is the step called?
Sense Starvation: - metabolic rate/energy –> development
What happens in step 2 of Myxococcus xanthus development into spores? How does it work? (Give specific chemical) What is the step called?
Form Aggregate: Starving cells secrete Phosphatidylethanolamine (PE), and the cells chemotax toward ++ [PE]
What happens in step 3 of Myxococcus xanthus development into spores? (5 Steps) What is the step called?
Differentiation: After cells form a mound…
- Some cells sacrifice themselves for food for others
- 15 new genes get transcribed for spore formation.
- Myxospores form.
- Stalk made of slime lifts spore up off surface.
- Germination.
What is the name of the spore?
Myxospore.
What causes germination? What happens then?
Food presence. Spore bursts open.
What are advantages of forming Myxospores? (List 3) Give explanation if needed.
- Metabolism
- Heat and UV resistance, due to carotenoids, which is a spore-specific protein that absorbs UV rather than letting it damage DNA
- Spores release at once many bacteria, creating a pack ready-made.
How does Myxococus xanthus reproduce?
Binary fission.
