Growing bacteria that degrade an environmental pollutant, which is also toxic to the cells at artificially high concentrations, might require ________ to obtain a sufficient population for biochemistry studies.
A) a continuous batch culture
B) a second growth substrate to keep the culture in exponential growth phase
C) steady state growth kinetics
D) the use of a chemostat
One laboratory group repeated the same experiment described by others with the identical bacterial isolate and the same growth medium and conditions used but were unable to achieve the same O.D. at 600 nm.
. What is the LEAST likely cause for this discrepancy of turbidity measured?
A) One lab used 16 mm wide test tubes and the other used 18 mm wide test tubes.
B) One lab subtracted the yellow color of the growth medium away from the final turbidity reported whereas the other lab used colorless water.
C) One lab vigorously dispersed the biofilm-forming bacteria with vortexing and the other did not.
D) The two labs varied with 1000 m elevation and did not consider the influence of pressure.
By controlling the concentration of nutrients added into a chemostat continuously, cells can constantly be maintained at
A) exponential growth phase.
B) stationary growth phase.
C) log or stationary growth phase.
D) death growth phase.
What is the function of bactoprenol?
A) It is a hydrophobic alcohol that transports peptidoglycan precursors across the cytoplasmic membrane.
B) It is responsible for forming the peptide cross-links between muramic acid residues in adjacent glycan chains.
C) It triggers the recruitment of FtsZ and the initiation of the divisome.
D) It supplies the energy necessary for transpeptidation to occur.
Which method would be LEAST effective at sterilizing a glass hockey stick to use in the spread-plate method?
A) autoclaving
B) gamma radiation
C) ethanol soaking
D) ultrahigh-temperature pasteurization
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