Microbiology: An Introduction
12th Edition
ISBN: 9780321929150
Author: Gerard J. Tortora, Berdell R. Funke, Christine L. Case
Publisher: PEARSON
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Chapter 7, Problem 5R
DRAW IT A bacterial culture was in log phase in the following figure. At time x, an antibacterial compound was added to the culture. Draw the lines indicating addition of a bactericidal compound and a bacteriostatic compound. Explain why the viable count does not immediately drop to zero at x.
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What method of bacterial measurement does this graph represent?
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A culture of E. coli has a concentration of 5 x 108cells/mL. How many times do you have todilute the culture so that when you spread 0.1mL on an agar plate you will have 250 colonies?Hint: you need to find dtotal and then convert it into a DF.
A new chemical disinfectant was tested for activity against Staphylococcus growth. The bacteria were incubated in bacterial growth medium + disinfectant for 24 hours, then one loopful of the mixture was transferred to fresh medium without the disinfectant (subculturing) and incubating the subculture. The initial culture and subcultures were evaluated for growth after incubation. (+ = growth; - = no growth)
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Initial
Subculture
1:2
-
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1:4
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1:8
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1:16
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1:32
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Chapter 7 Solutions
Microbiology: An Introduction
Ch. 7 - The thermal death time for a suspension of...Ch. 7 - If pasteurization does not achieve sterilization,...Ch. 7 - Thermal death point is not considered an accurate...Ch. 7 - Prob. 4RCh. 7 - DRAW IT A bacterial culture was in log phase in...Ch. 7 - How do autoclaving, hot air, and pasteurization...Ch. 7 - How do salts and sugars preserve foods? Why are...Ch. 7 - Prob. 8RCh. 7 - A large hospital washes burn patients in a...Ch. 7 - Prob. 10R
Ch. 7 - Which of the following does not kill endospores?...Ch. 7 - Which of the following is most effective for...Ch. 7 - Prob. 3MCQCh. 7 - Which of the following cannot be used to sterilize...Ch. 7 - Prob. 5MCQCh. 7 - The data were obtained from a use-dilution test...Ch. 7 - The data were obtained from a use-dilution test...Ch. 7 - Prob. 8MCQCh. 7 - A classmate is trying to determine how a...Ch. 7 - Which of the following is most likely to be...Ch. 7 - Prob. 1ACh. 7 - For each of the following bacteria, explain why it...Ch. 7 - A use-dilution test was used to evaluate two...Ch. 7 - To determine the lethal action of microwave...Ch. 7 - Entamoeba histolytica and Giardia lamblia were...Ch. 7 - Between March 9 and April 12five chronic...Ch. 7 - Prob. 3CAE
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