Extremophiles + Microbes

Question 1

What organism thrives under salty conditions, particularly sodium chloride?

Answer 1

Halophiles

Question 2

What organisms like to live in HOT conditions?

Answer 2

Thermophile

Question 3

Fungi vs bacteria, which one grows best under drier conditions?

Answer 3

Fungi!
Better adapted to grow in the absence of water.
Bacteria like moist, humid conditions.

Question 4

Why are the graphs for temperature generally asymmetrical?

Why is there a sharp decrease after optimum temperature?

Answer 4

It’s gone beyond a temperature the organism can cope with = sudden death for organism!
That’s why it’s NOT symmetrical and much sharper at the higher temperature!
Organisms can cope with cold temperatures.

Question 5

What temperature related processes kill ALL living cells?

Answer 5

Incineration

Flaming

Pasteurisation of milk destroys 99.9% of disease causing microorganisms!

Question 6

What organisms like it cold?

Answer 6

Psychrophile

Question 7

What microorganisms wouldn’t be killed by composting or pasteurisation?

Answer 7

Viruses

Archea!

Question 8

What type of organisms are present in tube 3? (Organisms throughout tube but denser strip near top of tube as that’s where oxygen would diffuse in and organisms present there would grow faster = higher density)

Answer 8

Facultative anaerobes
(will grow in the ABSENCE of oxygen BUT if oxygen is present it has the enzymes to cope with that and will use it as aerobic is more efficient / provides more energy!)

Question 9

What type of organisms are present in tube 4?
(Barely any dots suspended in liquid but a dense strip a bit under the top of the tube)

oxygen and bacterial growth

Answer 9

Microaerophillic (grow best under reduced atmospheric oxygen concentrations!)
That’s why the band of bacterial growth is a little bit under the surface as they thrive and grow there.

Question 10

What’s in tube 1?

All dots at top of tube

Answer 10

Obligate aerobe - NO organisms through depth of tube, everything is concentrated at the top where it can get supply of oxygen! (Can’t survive in ABSENCE of oxygen)

Question 11

What’s in tube 2?

All organisms at bottom of tube

Answer 11

Obligate anaerobe - can’t survive in presence of oxygen so everything at bottom of tube!

Question 12

What’s in tube 5?

Evenly distributed organisms throughout tube

Answer 12

Don’t rely on oxygen for their growth!

Question 13

What food preservation method uses LOW water activity to limit microbial growth?

Answer 13

Salting!

Question 14

What does bacterio / fungal static mean?

Answer 14

It means you’re just halting or inhibiting growth! (Keeps them in the stationary phase)
So if you REMOVE an antibiotic the growth can restart!

Question 15

What does bactericidal mean?

Answer 15

Means it kills bacteria!

Question 16

What stops the microbial cell membranes turning to liquid at high temperatures?

Answer 16

Saturated fatty acid molecules are present - they help to pack molecules closer together! Means it’s a more RIGID structure.

Question 17

Name a microbe FREE part of the human body.

Answer 17

The brain
Marrow
CNS

Question 18

The term micro biome is used to describe the list of taxa present in a niche (space).
True or false?

Answer 18

FALSE

Micro biome refers to the list of genes

Question 19

Which 3 phyla are mostly found in your mouth?

Answer 19

Bacteriodetes
Proteobacteria
Firmicutes

Question 20

What 2 phyla do we find in the gut?

Answer 20

Bacteriodetes

Firmicutes

Question 21

The Bifido bacterium increases as a proportion of our gut microbial population as we age.
True or false?

Answer 21

FALSE

It decreases as we age

Question 22

What 2 natural host defences help to keep the Urogenital Tract free of pathogens?

Answer 22

Low pH

High populations of lactobacillus species