Weeks 6 & 7: Microbial growth Flashcards
name some things that influence the generation time of an organism
environmental conditions such as temperature, available nutrients, pH, salt and pressure, and additionally genetics
what is a psychrophile?
capable of growing in cold temps
what is a thermophile?
grows best in higher temps
what is a halophile?
thrive in high salt conditions
lag phase of microbial growth:
cells begin synthesizing compounds such as proteins and DNA that are necessary for cell growth and division. lots of metabolic activity, but no cell division, so cell # remains the same
log/exponential stage of microbial growth:
cells divide rapidly, primary metabolites (such as certain AA) are harvested at this stage
stationary phase of microbial growth:
due to depletion of nutrients and the buildup of toxic metabolic by-products, the cells stop dividing. secondary metabolites (such as antibiotics) are harvested at this stage
what is harvested in the log/exponential stage of microbial growth?
primary metabolites, such as certain amino acids
what is harvested in the stationary phase of microbial growth?
secondary metabolites, such as antibiotics
which data should I use to calculate the generation time?
log/exponential/growth phase
what is generation time?
time it takes for a population of cells to double in number
where does an obligate aerobe grow in agar deep?
top of agar deep
what’s one example of an obligate aerobe?
Micrococcus luteus
where does an obligate anaerobe grow in agar deep?
bottom
what is an example of an obligate anaerobe?
Clostridium species
