Lecture 39: Microbial Growth and Behaviour

Question 1

Bacteria are so dominant due to:

Answer 1

• Fast growth rate
• Being around a long time
• Have colonized every single niche we can think of
• Being able to live in very diverse environments
• Being able to adapt selves to non-ideal environments

Question 2

Bacteria can grow on…

Answer 2

• Antibiotics
• Cells of dead products
• Excretory products
• Heavy Metals
• Animal Tissue
• Plant Tissue

Question 3

Bacteria reproduce asexually by a process called _____ ____.

Answer 3

• Binary Fission

Question 4

What do bacteria need to grow?

Answer 4

• Energy = ATP for catabolic and anabolic reactions
  ENERGY SOURCE
• Precursor metabolites = organic building blocks
  CARBON SOURCE
• Reducing Power = NADH/NADPH
  Photoautotrophs fix CO2

Question 5

Catabolism vs. Anabolism

Answer 5

• Energy Generation

- Energy Consumption

Question 6

Chemoheterotrophs:

Answer 6

• Anaerobic respiration: most animals, fungi, and protozoa

Question 7

Heterotrophs =

Answer 7

• Feeding on other organisms

Question 8

Autotrophic =

Answer 8

• Getting energy from self

Question 9

Microbrial Growth “Feast or Famine”:

Answer 9

• Lag phase
  Engine is running but we haven’t undergone replication yet, haven’t gone into cell division yet
• Exponential phase
  Actively dividing and nothing is limiting for growth. Population is doubling in a constant time interval
• Stationary phase
  Something has become limited, run out of food, competition for space
• Death phase

Question 10

Bacteria has this amazing ability to stay ______ during the stationary phase.

Answer 10

• Viable (alive + not dividing)

Question 11

Antibiotics in general target the …

Answer 11

• Cell Wall

- However only replicating cells

Question 12

Persisters are bacteria that are…

Answer 12

• Doing something different than the other bacteria

- Resistant because of their physiological state (NON-DIVIDING)

Question 13

Need to take antibiotics to kill the _____.

Answer 13

• Persisters
• Otherwise you have a persister infection
• Not resistance, it’s persistance

Question 14

Small size? NO. Daughter cells grow inside …..

Answer 14

• Mother cell

Question 15

Bacteria is…

Answer 15

• Highly ordered and dynamic
• Capable of polarizing and differentiation into cell types
• Signal each other to coordinate multicellular actions
• Intracellular organization
• Anticipate changes in the environment

Question 16

Outline some examples of microbial behaviour:

Answer 16

• The social prokaryotes (myxobacteria)
• Gram-negative bacteria capable of multicellular and social behaviour
• Model system for the study of social behaviour in Prokaryotes
• Social gliding motility (hunt as pack and eat other bacteria)
• When they run out of things to eat, they stop and build big structures and make spores
• NO FLAGELLA
• Two engines, S-engine = grappling hook, A-engine = excrete slime and push
• Present at both poles of cell
• Aggregation = make fruiting body, talking to each other to make mound (when they’ve run out of nutrients)
• Myxospores = resistant to starvation