Microbial Diversity

Question 1

Explain microbial diversity briefly

Answer 1

They can exist in any pH and at extreme temperatures. they can live in deep sea thermal vents or area’s of very high salt concentrations. Prokaryote diversity is very large.

Question 2

True or false, Prokaryotes take up way more niches than Eukaryotes

Answer 2

True!! Every niche with eukaryotes has prokaryotes but not vice versa.

Question 3

True or false, one gram of dental plaque has more bacteria than humans to ever live on earth?

Answer 3

True!! Each year, humans excrete their own body weight of bacteria.

Question 4

What bacteria proves we cannot judge if an organism is prokayrote or eukaryote by size?

Answer 4

Thiomargarita namibiensis!!
Largest bacterium on earth
100 million times larger than E. Coli

Question 5

What bacteria is found in chains of 12 balls?

Answer 5

thiomargarita namibiensis

Question 6

Explain Nanoarchaeum Equitans?

Answer 6

• very tiny bacterium
• only can grow when attached to host microbe
• lives in very hot conditions of 95 degrees
• not smallest microbe

Question 7

Explain Ultra-small bacteria

Answer 7

• can pass through a 0.2um filter
• found in ground water, uncultivated in lab
• smaller than some viruses
• 150 can fit into one E. Coli cell

Question 8

What is Mollivirus Sibericum

Answer 8

• 30,000 year old Giant virus found in melting ice
• still infectious after being defrosted
• it is 0.6um

Question 9

What did Mollivirus sibericum prove about chamberlands work?

Answer 9

the notion that viruses are always smaller than bacteria disproved his Chamberland filters.

Question 10

Explain the Pandoraviruses

Answer 10

Giant viruses which is 1.2 by 0.5 um !!

Question 11

Explain Hyperthermophiles

Answer 11

they have optimum growth of above 80 degrees!
Often found by hydrothermal vents
mostly archaea with very few bacteria
no eukaryotes

Question 12

What is the highest optimum for hyperthermophiles?

Answer 12

105 degrees however they have existed in up to 121 degrees (just not optimum) . This is a problem because an autoclave is suppose to kill off any microbe yet some can survive it!!

Question 13

Explain Geogemma barossi

Answer 13

A hyperthermophile that exists at 121 degrees. Denounces the autoclave. At 105 degrees this bacteria doubles in population!

Question 14

explain the ampulla virus

Answer 14

A virus that infects hyperthermophiles.

Question 15

explain the AfV1 virus of acidianus

Answer 15

This virus is long and thing and has pincers which cling onto infected cells.

Question 16

Explain Picrophillus

Answer 16

• is an acid loving archaea

- it grows in an optimum of 0.7 pH but can exist in even 0 pH. Lowest of any prokaryotes

Question 17

What does optimum growth conditions infer?

Answer 17

The conditions that provide the lowest generation time
For Picrophillis this would be a pH of 0.7
For geogemma barossi it would be 105 degrees

Question 18

What is the fastest organism on earth? is it archaea or bacteria or eukarya?

Answer 18

methanocaldococcus villosus. It travels at 470 bodylengths per second!! It is an Archaea!! It is hyperthermophillic
cheetah’s run 20 body lengths per second.

Question 19

What is the fastest bacteria on earth? how fast?

Answer 19

Bdellovibrio which can travel at 100 body lengths per second!! It only uses one flagella to accomplish this!!

Question 20

Explain predatory prokaryotes

Answer 20

bacteria that prey on other bacteria. They use the prey as a source of nutrients. They cannot be grown in media regardless of nutrients. They need host cells as prey.

Question 21

Explain Bdellovibrio as a predatory prokaryote

Answer 21

• It uses speed to attack prey
• enzymes break down membrane
• it burrows itself into the periplasm and utilizes nutrients.

Question 22

Explain vampirecoccus

Answer 22

• predatory prokaryote

- remains outside of cell and sucks in prey nutrients

Question 23

Bacteria were found in bubbles of 250 million year salt crystal. Believed the high salt concentration sustained a dormancy of these microbes.

Answer 23

pretty cool. Salt may have came from a meteor therefore its extraterrestrial bacteria.
That said, 16sRNA showed resemblance to dead sea bacteria

Question 24

Explain Bioluminescent bacteria

Answer 24

• found in light organs of fish in symbiotic relationship
• ## they will only give off light at very high cell densities

Question 25

the concept of expressing a gene only when cell population density is high is called?

Answer 25

Quorum sensing

bioluminescent bacteria express light gene in high densities

Question 26

What is the benefit of Quorum sensing

Answer 26

it allows bacteria to coordinate behaviour. Bacteria communicate with each other by releasing signal molecules. when this are high quorum sensing occurs.

Question 27

how do pathogens use quorum sensing?

Answer 27

Pathogens use it to regulate expression of virulence factors

Question 28

Who was Robert Ballard

Answer 28

Discovered the wreck of the titanic

Question 29

What are rusticles?

Answer 29

Bacteria consortia is ‘eating’ the titanic
extracting iron from steel of hull
creates icicles made up of 30% extracted iron

Question 30

What are Halomonas Titanicae?

Answer 30

one of the bacteria eating the titanic

Question 31

t or f, 10^8 bacteriophages in a drop of water

Answer 31

true

Question 32

What does large number of bacteria viruses indicate?

Answer 32

Control over bacteria population or the mediation of gene transfer via transduction (virus transfers genes to different kinds of bacteria)

Question 33

What is microbial paint?

Answer 33

different kinds of bacteria produce different proteins. Some are pigments of different colours! Cells are colourless on agar plate until they grow colonies.

Question 34

what is a microbial colony?

Answer 34

A cluster of microbes on an agar plate (or any medium) that presumably started from one cell