Microbiology an Introduction: The Rate of Microbial Death Flashcards
it is easy to kill large number of populations very early on
is it difficult to kill the last remaining few organisms
why is it hard to kill the last remaining few organisms?
can divide quickly and replace population
how many factors affect death rate
the number of microbes is a factor that affects microbial death rate
environmental factors is a factor that affects microbial death rate
time of exposure is a factor that affects microbial death rate
the characteristic of the microbe is a factor that affects microbial death rate
what does the number of microbes as a factor mean?
larger populations take longer to kill
what types of environmental influences affect death rate?
temperature, containing organic material, and biofilms
how does temperature affect death rate?
most chemicals are more effective when heated
what types of organic materials inhibit the killing of microbes?
blood, vomit, feces, and urine
biofilms are made of
extracellular polymeric substances
mucoid matrix is made of EPS and is difficult to penetrate.
what two environmental influences inhibits the killing of microbes?
if it contains organic material or if it has a biofilm
what does the time of exposure as a factor mean?
longer times are more effective, especially as chemical concentrations change
Mycobacterium is not too waxy to be penetrated by polar chemicals
Pseudomonas are especially resistant to chemials
what are prions
spores and cysts are inactive, resistant forms
know this arrow
most resistant is the same as hard to kill
least resistant means the same as hard to kill
most resistant = least susceptible
least susceptible = most resistant
most susceptible = least resistant
least resistant = most susceptible