MICROBIAL GROWTH PHASES I Flashcards
time it takes for a single cell to go from one division to next
generation time/doubling time
how bacterial population increases
exponentially/logarithmically
where organisms are “getting used to the medium and physical conditions
lag phase
this is the phase where the generation time is measured.
log phase
during this phase, the number of new cells equals the number of dead cells.
stationary phase
rate of cell death is faster than regeneration.
death phase
GENERAL MICROBIAL GROWTH CONTROL with meaning
sterilization - complete destruction
commercial sterilization - heat treatment
disinfection - inanimate surfaces
antisepsis - living tissue
degerming - mechanical removal
sanitation - lower microbial counts
antibiotic - agent, kills other microorganisms
MICROBIAL GROWTH PHASES:
lag phase
log phase
stationary phase
death phase
types of HEAT:
moist heat
pasterization
tindallization
dry heat
PHYSICAL METHODS OF MICROBIAL CONTROL
heat
filtration
cold
high pressure
desiccation
osmotic pressure
radiation
types of dry heat and the 3 parameters:
hot air oven
direct flaming
incineration
THERMAL DEATH POINT
THERMAL DEATH TIME
DECIMAL REDUCTION TIME
physical separation of bacteria from suspending liquid
filtration
this type of air filter can theoretically remove at least 99.97% of dust, pollen, mold, bacteria, and any airborne particles with a size of 0.3 microns (µm).
HEPA (high efficiency particulate air filter)
decreases chemical reactions and possible changes in protein
cold
types of COLD with meanings
refrigeration - slows down
deep-freezing - dormant stage
lyophilization - long term preservation
