Test 3 VOCAB Flashcards
Grow optimally at 80-110 C
*hot springs
Hyperthermophiles
Grow between 40-70c
*hotsprings
Thermophiles
Grow between 10 - 50C
Mesophiles
Grow between 0-30 C
Psychrotrophs
Grow between -10 - 20 C
Psychrophiles
bacteria that is extremely tolerant to low pH
*high use in industry / coal
Acidophiles
Require high salt concentrations and can survive 30% solutions
Obligate halophiles
do not require high salt concentrations but can survive up to 12%
Facultative halophiles
An enzyme that breaks down superoxide radicals (02-)
and what reaction does it catalyze?
Superoxide dismutase
02- + 02- + 2H+ = H2O2 + 02
2 superoxide radicals plus 2 protons = Hydrogen peroxide and normal oxygen
An enzyme which catalyzes hydrogen peroxide into 2 water molecules and oxygen
Catalase
Allows us to grow organisms in a lab under controlled defined conditions, can be chemically defined, solid or liquid, aerobic or anaerobic
Culture media
When we introduce bacteria on to a media
Inoculation
Bacteria that was introduced onto a media is called
Inoculum
as bacteria grows it is called a
culture
media in which we do not know everything in it or how much
*typically contains extracts
Complex media
Media in which we know everything in it as well as how much of it
Chemically defined media
Complex polysaccharide derived from marine algae
Agar
Oven-like creations which can hold many important factors constant
Factors such as: Temp, % CO2, %hydrogen, moisture,
Incubator
Small vessels which we can add CO2 as well as remove oxygen to reproduce anaerobic conditions
Anaerobic jar
Studying one bacteria at a time
Pure culture
Media that allows for one microbe to be differentiated from others grown on a plate
Differential media
Media that encourages the growth of a target organism and supressing or stopping the growth of other organisms
Selective media
Media that can increase the number of target bacteria to culture it out of a sample
Enrichment media
Time required for one cell to divide and become 2
*time it takes a population to double
Generation time
Occurs when cells are first inoculated into a culture and are adjusting
Lag phase
The phase in which cells are actively dividing at a constant min generation time
*straight line on log scale
Log phase
When nutrients run out, waste will build up and pH will change. Cells begin to die and growth slows
*WHen # of deaths reaches # of divisions the growth rate becomes 0
Stationary phase
Nutrients continue to decrease and toxicity of media increases, # of deaths overtakes the # of divisions
*decline in growth curve
Death phase
Where a sample is combined with molten agar (50C) and poured into a plate
Pour plating
A sample of bacteria is spread over the top of a solidified plate of agar
Spread plate
Culture is combined with cryoprotectant (antifreeze) then rapidly frozen and maintained at extremely low temps
*usually in liquid nitrogen
Snap freezing
Lyophilization
Aggregates of microbes living in a slimy layer of DNA, proteins and polysaccharides
Extracellular polymeric substance (EPS)
complex microbial communities
Biofilm
a microbiological growth media that chemically combines with dissolved oxygen and removes the oxygen from the media
reduced media
Refers to a microbial contamination
Sepsis
The absence of significant microbes (that cause disease)
Asepsis
Techniques designed to prevent microbial contamination
Aseptic technique
Removal of microbial life
Sterilization
Removal of pathogens
Disinfection
Removal of pathogens from living tissue
Antisepsis
modification of disinfection where microbes are removed from area usually by mechanical means
Degerming
Process of lowering microbial counts by cleaning
*typically used with inanimate objects
sanitization
Compound that kills microbes
Biocide/germicide
Inhibiting, not killing, microbes
Bacteriostasis
Lower heat is applied for a longer time to achieve microbial reduction, not elimination
Pasteurization
Heat alters the 3D structure of proteins by disrupting the bonds
Denaturation
Once proteins have been denatured they will bind together to form aggregates
Coagulation
Lowest temp at which cells in a culture are killed in 10 mins
Thermal death point (TDP)
Time to kill all cells in a culture
Thermal death time (TDT)
Minutes to kill 90% of population at a given temp
Decimal reduction time
*aka log reduction time
Pressure applied in a closed system to reach elevated temps
Autoclave
Shortest wavelength and most energy
This form can penetrate
*hits and ionizes cell structures like DNA and proteins
*Hits and ionizes water to reactive oxygen species
Ionizing radiation
Uses UV light, a longer wavelength
*non-penetrating
Interacts with DNA resulting in the formation of thymine dimers which prevent proper DNA replication
Non-ionizing radiation
Prevent proper DNA replication
*throws off the DNA complementary so they don’t bind across but instead to each other next to each other
Thymine dimers
Work by spinning polar molecules, generating heat
cannot ionize water
Microwaves
Rings are dipped into standardized cultures of bacteria
Then removed and dried
Rings are then dipped into cleaning agent per manufacturers recommended instructions
*10 mins at 20 C
Rings are placed in media and growth observed
Use dilution test
Filter paper is soaked in an agent
bacteria is spread over a plate
Disks placed on top
observe
Disc diffusion
Areas of clearing around the item that has cleaner on it, not allowing bacteria to grow there
Zone of inhibition
Aqueous solution of iodine
fast acting release
Tincture
Iodine with an organic molecule
slower acting but longer lasting
Iodophore
Some heavy metals are shown to have antimicrobial activity
Trace amounts of medal diffuse and interact with bacteria causing protein denaturation and lipid dissolution
Oligodynamic action
