Microbial Diversity Flashcards
Explain microbial diversity briefly
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.
True or false, Prokaryotes take up way more niches than Eukaryotes
True!! Every niche with eukaryotes has prokaryotes but not vice versa.
True or false, one gram of dental plaque has more bacteria than humans to ever live on earth?
True!! Each year, humans excrete their own body weight of bacteria.
What bacteria proves we cannot judge if an organism is prokayrote or eukaryote by size?
Thiomargarita namibiensis!!
Largest bacterium on earth
100 million times larger than E. Coli
What bacteria is found in chains of 12 balls?
thiomargarita namibiensis
Explain Nanoarchaeum Equitans?
- very tiny bacterium
- only can grow when attached to host microbe
- lives in very hot conditions of 95 degrees
- not smallest microbe
Explain Ultra-small bacteria
- 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
What is Mollivirus Sibericum
- 30,000 year old Giant virus found in melting ice
- still infectious after being defrosted
- it is 0.6um
What did Mollivirus sibericum prove about chamberlands work?
the notion that viruses are always smaller than bacteria disproved his Chamberland filters.
Explain the Pandoraviruses
Giant viruses which is 1.2 by 0.5 um !!
Explain Hyperthermophiles
they have optimum growth of above 80 degrees!
Often found by hydrothermal vents
mostly archaea with very few bacteria
no eukaryotes
What is the highest optimum for hyperthermophiles?
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!!
Explain Geogemma barossi
A hyperthermophile that exists at 121 degrees. Denounces the autoclave. At 105 degrees this bacteria doubles in population!
explain the ampulla virus
A virus that infects hyperthermophiles.
explain the AfV1 virus of acidianus
This virus is long and thing and has pincers which cling onto infected cells.
Explain Picrophillus
- 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
What does optimum growth conditions infer?
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
What is the fastest organism on earth? is it archaea or bacteria or eukarya?
methanocaldococcus villosus. It travels at 470 bodylengths per second!! It is an Archaea!! It is hyperthermophillic
cheetah’s run 20 body lengths per second.
What is the fastest bacteria on earth? how fast?
Bdellovibrio which can travel at 100 body lengths per second!! It only uses one flagella to accomplish this!!
Explain predatory prokaryotes
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.
Explain Bdellovibrio as a predatory prokaryote
- It uses speed to attack prey
- enzymes break down membrane
- it burrows itself into the periplasm and utilizes nutrients.
Explain vampirecoccus
- predatory prokaryote
- remains outside of cell and sucks in prey nutrients
Bacteria were found in bubbles of 250 million year salt crystal. Believed the high salt concentration sustained a dormancy of these microbes.
pretty cool. Salt may have came from a meteor therefore its extraterrestrial bacteria.
That said, 16sRNA showed resemblance to dead sea bacteria
Explain Bioluminescent bacteria
- found in light organs of fish in symbiotic relationship
- ## they will only give off light at very high cell densities
the concept of expressing a gene only when cell population density is high is called?
Quorum sensing
bioluminescent bacteria express light gene in high densities
What is the benefit of Quorum sensing
it allows bacteria to coordinate behaviour. Bacteria communicate with each other by releasing signal molecules. when this are high quorum sensing occurs.
how do pathogens use quorum sensing?
Pathogens use it to regulate expression of virulence factors
Who was Robert Ballard
Discovered the wreck of the titanic
What are rusticles?
Bacteria consortia is ‘eating’ the titanic
extracting iron from steel of hull
creates icicles made up of 30% extracted iron
What are Halomonas Titanicae?
one of the bacteria eating the titanic
t or f, 10^8 bacteriophages in a drop of water
true
What does large number of bacteria viruses indicate?
Control over bacteria population or the mediation of gene transfer via transduction (virus transfers genes to different kinds of bacteria)
What is microbial paint?
different kinds of bacteria produce different proteins. Some are pigments of different colours! Cells are colourless on agar plate until they grow colonies.
what is a microbial colony?
A cluster of microbes on an agar plate (or any medium) that presumably started from one cell
