Motility 2

Question 1

What is the master TF for sporulation?

Answer 1

Spo0A

Question 2

WHat must happen for Spo0A to be active?

Answer 2

It must be phosphorylated (Spo0A-P)

Question 3

What does low levels of Spo0A lead to?

Answer 3

Production of antimicrobials, proteases, competence–> vegetative growth continues

Question 4

What does high levels of Spo0A lead to?

Answer 4

Endospore production

Question 5

What are the two types of cell expressed during sporulation?

Answer 5

Mother cell and forespore

Question 6

Which sigma factors are expressed in the mother cell (early and late)?

Answer 6

Early–> E
Late–> K

Question 7

Which sigma factors are expressed in the forespore(early and late)?

Answer 7

Early–>F
Late–> G

Question 8

What kind of division happens to create a forespore?

Answer 8

Asymmetric–> mother cell is a lot bigger than forespore

Question 9

What is the DNA held in in an endospore?

Answer 9

The core–>Partially dehydrated, water is replaced by dipicolinic acid and Ca2+

Question 10

WHat does the cortex do in an endospore?

Answer 10

Protects the core

Question 11

What is the cortex in an endospore made up of?

Answer 11

Unique form of peptidoglycan
Made from 3 repeat subunits
Low level of crosslinking

Question 12

What part of an endospore protects it from radiation?

Answer 12

Crust

Question 13

Stages of endospore germination ?

Answer 13

Activation, germination and outgrowth

Question 14

Activation of germination?

Answer 14

Germinant receptors on the outside of the spore can sense the presence of a favourable environment/germinant

Question 15

Germinationof germination?

Answer 15

Endospore structures degraded, dipicolinic acid released

Question 16

Outgrowth of germination?

Answer 16

swelling of core and expansion of cell, return to normal metabolic activity

Question 17

Endospore stability?

Answer 17

Metabolically inactive and can survive w/o nutrients and water
Survive extreme temps and chemical treatments
Can remain dormant for many yrs

Question 18

What is a biofilm?

Answer 18

Multicellular bacterial community, often on a surface or at an interface, with the cells embedded in extracellular matrix in complex 3D architecture

Question 19

How do the majority of bacteria on earth exist?

Answer 19

In a biofilm

Question 20

What do microbial communities usually attach themselves to?

Answer 20

A surface (abiotic or biotic)

Question 21

Where can bacillus form a biofilm?

Answer 21

At the air-water interface on a liquid, or on solid surfaces

Question 22

What needs to be produced for the first stage of biofilm formation to occur?

Answer 22

A flagella

Question 23

What is the reversible attachment phase of biofilm formation?

Answer 23

The bacteria attach themselves to a surface, but if something happens they can also remove themselves

Question 24

What follows reversible attachment in biofilm formation?

Answer 24

Irreversible attachment

Question 25

What happens in irreversible attachment?

Answer 25

The bacteria start changing their gene expression

Question 26

What are some genes that are changed in irreversible attachment?

Answer 26

Flagella genes are downregulated, EPS genes are upregulated

Question 27

What is the EPS?

Answer 27

Sticky, extracellular substance that protects the biofilm

Question 28

What follows irreversible attahcment?

Answer 28

Phases of maturation (I, II, etc)

Question 29

What occurs in the phases of maturation?

Answer 29

Creating a cell cluster, cell division, growing the size of the biofilm

Question 30

What happens if something happens to the biofilm (e..g low nutrient level)?

Answer 30

The bacteria can disperse, change gene expression (flagella genes up)