Control of microbial growth Flashcards
what is sterilization
the killing of all viable organisms (including virus) with a growth medium
list methods that can be used to inhibit or limit the growth of microorganisms
decontamination
disinfection
what is decontamination
the treatment of an object or surface to make it safe to handle
what is disinfection
the removal of all pathogenic organisms
what are the three classes of physical control
heat sterilization, radiation and filtration
how can we measure the effectiveness of heat as a sterilant
by the time required at a given temperature for a 10-fold reduction in the viability of a microbial population
what is decimal reduction time(D)
the time required at a given temperature for 10-fold reduction in a viable microbial population.
what is thermal death time
the time it takes to kill all cells with at a given temperature
high concentration of what macromolecules can decrease heat penetration
sugars, proteins and fats
at what temperature and time is required to achieve sterilization in an autoclave for small amount of endospore
121 degrees Celsius for 15mins
what is the difference between sterilization and pasteurization
sterilization is the removal of all viable microorganisms including viruses while pasteurization is the use of heat to reduce not all microorganisms in a liquid
what is generation time
time it takes for microbial cells to double in size
the period between inoculation and onset growth
lag phase
the period where cells double in regular intervals is called
exponential phase
another word for exponential phase
balanced growth
