Growth Requirements Flashcards
what are the 4 stages of binary fission?
cell elongates and DNA duplicates, membrane forms a septum, septum completes and the daughter cells separate
how is a tetracocci formed?
2 planes of division across one cocci
how is a sarcinae formed?
3 planes of division across one cocci
what does formation of a sarcinae lead to?
staphylococci
what is generation time?
time required for a cell to divide
what is the average generation time?
about 1-2 hours
what is the lag phase?
no overall increase in cells with intense metabolic activity
what is the log phase?
maximum growth rate for that environment
what is the stationary phase?
balance between cell division and death
what are the features of the stationary phase?
metabolically active so exhaustion of nutrients occurs, waste accumulates and spores form
what is the death phase?
cell lysis
what is the advantages of continuous culture?
continuous log phase, no nutrient limitation, and easy to control the environment
what does a continuous culture set up consist of?
influx of fresh medium and sterile air or gas, which forms a layer of culture and gaseous headspace and and overflow is effluent that contains microbial cells
what us sterilization?
killing of removal of all living organisms and their viruses
what is disinfection?
elimination of microroganisms from inanimate objects
