Culture Media
I want to isolate a microbe that grows on phenol, so I place it in a liquid medium that has phenol as the only source of carbon and energy. What kind of culture is this?
Enrichment culture
Extreme halophiles?
salt loving bacteria, require salt to grow
Define carrying capacity
# of organisms an environment can support
Name literally one direct measurement of microbial growth, like you don't even have to define it
Plate count, serial dilution, pour plates, spread plates, filtration, most probable number method, direct microscopic count
Describe what a BSL-1 lab would be
Basic microbiology teaching lab
My blood agar shows signs of hemolysis (clear halos), what kind of culture media would this be?
Differential media
Thermophiles?
Heat loving microbes, optimal growth temperature of 50-60° C
Process where a pure culture of microbes is placed in a suspending liquid and quick frozen at temps ranging from -50° C to -95° C
Deep freezing
Used often to detect coliform bacterium, which indicate fecal contamination of food or water
Filtration
Describe how turbidity works
Light passes through the test tube, and a detector senses how much light passes through the tube, giving a reading. Cloudy patches of bacteria scatters light.
fastidious
Anaerobes
Bacteria using gaseous nitrogen directly from the atmosphere
Nitrogen fixation
What is the slide called that allows you to perform direct microscopic counts?
Petroff-Hausser cell counter
Describe what is happening in the death phase (very appropriate for the category)
Number of bacteria dying exceeds the number of new cells formed
An obligate anaerobe must be grown in a petri dish, how can this be done?
Incubate microorganisms in sealed boxes and jars where oxygen is chemically removed, anaerobic chambers are also an option
Capnophiles
Carbon dioxide loving organisms
Define quorum sensing
Bacteria communicating and coordinating behavior by distributing inducers
I want to count and see characteristics of the colonies I'm planning to grow, which direct method should I use?
Spread plate method, colonies grow on surface of medium, and you can count them!
Describe to me why Staphylococcus aureus is yellow on my mannitol salt agar and what this means about the culture media
S. aureus can ferment mannitol, and this means this media is a differential media
Biosafety level 4 labs is the highest level a lab can reach. We have a nickname for BSL-4 labs, what is that nickname, and give an example of a pathogen that would be handled in a BSL-4 lab.
the hot zone, ebolavirus
Mesophiles?
Moderate temperature loving microbes, 37° C optimal
Forming a small initial outgrowth that enlarges until its the size approaches that of the parent cell, and then separates
Budding
Explain serial dilution
You split up 1 ml of a sample to 9 ml of a sterile liquid, and continue this until you have diluted the sample to plate a countable number of colonies, then do some math to figure out how many bacteria were in the original sample. If any of you put a better answer than this I am proud of you
Describe what superoxide dismutase does
Neutralizes superoxide radicals which can be toxic to the cellular components of bacteria