Chapter 7 Flashcards
Increase in cellular constituents
growth
Period of apparant inactivity during which the cells are adapting to a new environment and synthesizing new cell components. Short & very long.
lag phase
Period during which the organisms are growing at the maximal rate possible given their genetic potential, smooth curve.
exponential phase
Period in which teh number of viable microbes remains constant either because they metabolically stop reproducing or because the reproductive rate is balanced by the rate of cell death.
stationary phase
Why does growth cease??
- Nutrients used up
- Oxygen used up
- Toxic waste produced
Starved cells may enter a state called _____________, a dormant state relieved by an appropriate change in environment.
VBNC - viable but nonculturable
The length of time it takes for a population of microbes to double in number.
generation time
The number of generations per unit time, usually expressed as the number of generations per hour.
mean growth rate constant (k)
The number of cells per unit volume that are able to grow and reproduce.
viable cell count
A process by which bacteria communicate and carry out certain activities.
quorum sensing
A culture system with constant environmental conditions maintained through continual nutrient provision and waste removal.
continuous culture
A type of continuous culture in which sterile medium in limiting quantities is fed in at same rate as media w/ microbes removed.
chemostat
A type of continuous culture in which teh flow rate of medium through the vessel is automatically regulated to maintain a predetermined turbidity
turbirdostat
Organisms that grow over a fairly wide range of water activity.
osmotolerant
Organisms that require high levels of NaCl
halophiles
Organisms that have optimum growth between pH 0-5.5
acidophiles
Organisms that have optimum growth between pH 5.5-8.0
neutrophiles
Organisms that have optimum growth between pH 8.5-11.5
alkaliphiles
minimum, optimum, and maximum temp
cardinal temps.
Organisms that have optimum growth at 15C or lower
psychrophiles
Organisms that have optimum growth between 20C-30C
psychrotrophs
Organisms with optimum growth between 20-45C
mesophiles
Organisms with optimal growth between 55-65C
thermophiles (tide)
Organisms with optimal growth between 80-110C
hyperthermophile
Organisms completely dependent on oxygen.
obligate aerobe
Organisms that do not require oxygen for growth, but grow better in its presence.
facultative anaerobe
Organisms that ignore oxygen and grow equally in presence/absence of oxygen
aerotolerant anaerobe
Organisms that require oxygen at levels in the range of 2-10% for growth and are damaged by normal atmospheric (20%). Basically need less oxygen
microaerophiles
Organisms that grow more rapidly at increased barometric pressure.
barophiles
Organisms that grow in harsh environments that would kill most living organisms.
extremophiles
Complex involved in replication of the prokar. chromosome
replisome
Starved cells may enter this state.
VBNC
