How do we study microbes and all the jazz?
Culture them
Ingest them
Look at them under a microscope
Study their DNA, RNA, and proteins!
Complex media is harder to make and every single ingredient is measured.
General Media has which of the following characteristics?
Super selective
Great Plate Count Anomaly
Still can’t culture everything
Cultures as many microbes as possible
Enrichment media has which of the following characteristics/example(s)?
Culture fastidious organisms
Chocolate agar
Mannitol Agar
Add things to the media to enable specific types of bacteria to grow
❌ media selects for certain bacteria and selects against other bacteria.
Differential media usually is dependent on bacterial metabolic activity.
Differential media is not similar or at all like selective media.
Choose the correct terms for the following characteristics of autoclaving. Autoclaving uses high and high temperature to kill even . heat has more energy than dry heat. This kills everything but can be for delicate or reactive compounds. Autoclaving can also cause to . Also, trace metals that are -sensitive might react and become unavailable.
If autoclaving can denture vitamins and ruin or cause trace metal react, then what is another method of sterilization that would be better suited to handle this problem?
UV light
Filter sterilization
Bleach
Clorox Bleach-Free Fabric Sanitizer
Which of the following is TRUE about filtered sterilization?
Used for reactive compounds (vitamins or trace metals)
Removes the cells from the liquid, as autoclaving kills cells but doesn’t necessarily destroy them.
Requires UV lamp
Need cell-free water to do dilutions for microscope counts
Which is not a form of UV light sterilization?
UV-2
UV-A
UV-C
UV-B
Order the strength of UV light sterilization in increasing order in terms of effectiveness of killing microbes: 1) Lowest --> UV-A UV-B UV-C( UV-A, UV-B, UV-C ) 2) Medium --> UV-B UV-A UV-C( UV-B, UV-A, UV-C ) 3) Highest --> UV-C UV-A UV-B( UV-C, UV-A, UV-B )
UV-A is the least effective in killing microbes but has the deepest penetrance. UV-C is the most effective in killing microbes but has the lowes penetrance.
Hypothermiphiles and thermophiles grow in environments. Psychrophiles grow in environments. Halophiles love . Osmophiles love . Xerophiles grow in environments.
What is true about thermophiles?
They love cold environments
They have unsaturated fatty acids
They have saturated fatty acids
They use unsaturated fatty acids to increase the melting temperature of the cell membrane.
The closer to 1, the purer the water solution.
Why do we use salt and sugar in food preservation?
Gives it a good flavor
They feed the bacteria
Reduces the food from looking bad
Reduces water activity
We can use microbes to preserve our food by them producing acid. This method of food preservation is called?
Fermentation
Salting
Sugaring
Acidification
Canned fruits naturally have higher acid than canned meat or vegetables as they have naturally occurring acidity prevents the growth of this bacteria.
E. coli
C. botulinum
Listeria
Anaerobes
What is pasteurization?
Heating food at a HIGH temperature for a LONG time to kill bacteria without destroying the nutritional value or dramatically altering the flavor of the food
Heating food at a LOW temperature for a SHORT time to kill bacteria without destroying the nutritional value or dramatically altering the flavor of the food
Heating food at a HIGH temperature for a SHORT time to kill bacteria without destroying the nutritional value or dramatically altering the flavor of the food
Heating food at a LOW temperature for a LONG time to kill bacteria without destroying the nutritional value or dramatically altering the flavor of the food
What is true about anaerobes?
Boiling water to remove gas is needed to make anaerobic media.
Anaerobes need air to survive
Some obligate anaerobes have superoxide reductase
Obligate anaerobes can thrive in the presence of oxygen
They cannot utilize oxygen as an electron acceptor
Which type of organism contains a protein-free manganese complex instead of superoxide dismutase?
Aerobes
Microaerophiles
Aerotolerant
Obligate anaerobes
Aerobes and facultative aerobes always have and .
Some aerotolerant organisms have instead of
Obligate anaerobes have instead of .
Which of these organisms utilize oxygen as a terminal electron acceptor?
Facultative aerobes
Bacteriocidal kills destroys breaks down( kills, destroys, breaks down ) the bacteria, bacteriostatic stops grows slows( stops, grows, slows ) bacterial growth, and bacteriolytic destroys hides nurse( destroys, hides, nurse ) the cells.
destroy all microorganisms including endospores are used on surfaces to kill microorganisms but not necessarily endospores reduce microbial numbers but do not sterilize kill or inhibit microbial growth, but are non-toxic enough to be applied to living tissue
