Microbiology: An Introduction
12th Edition
ISBN: 9780321929150
Author: Gerard J. Tortora, Berdell R. Funke, Christine L. Case
Publisher: PEARSON
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Textbook Question
Chapter 6, Problem 1A
E. coli was incubated with aeration in a nutrient medium containing two carbon sources, and the following growth curve was made from this culture.
- a. Explain what happened at the time marked x.
- b. Which substrate provided “better’ growth conditions for the bacteria? How can you tell?
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Below is shown a growth curve for an E. coli culture. As indicated, the culture was incubated in the absence of a carbon source for 2 hours until Glucose and Lactose were added; Glucose was used up after 5 hours, and Lactose was used up after 8 hours. During the time-course, you take four samples, labeled A-D, after 1, 3, 7 and 9 hours, respectively, as indicated under the graph. Assuming there is cAMP present at t=0, for each sample identify whether CAP and/or the Lac Repressor would be bound to the DNA, and explain why.
Below is shown a growth curve for an E. coli culture. As indicated, the culture was incubated in the absence of a carbon source for 2 hours until Glucose and Lactose were added; Glucose was used up after 5 hours, and Lactose was used up after 8 hours. During the time-course, you take four samples, labeled A-D, after 1, 3, 7 and 9 hours, respectively, as indicated under the graph. Assuming there is cAMP present at t=0, for each sample identify whether CAP and/or the Lac Repressor would be bound to the DNA, and explain why.
A microbiology student was given a mixed culture of two different gram positive bacteria species to grow into a culture medium using correct aseptic techniques. After two days,one gram positive bacterial species grew on the media and the growth appeared red on the surface of the medium. Tthe second gram positive bacterial species grew and the growth appeared yellow on the surface of the medium. What is the possible explanation for the differences in the color of the bacterial growth?
A.
the culture was contaminated
B.
the microbiologist put too much inoculum on the culture medium
C.
the medium was a selective medium
D.
the medium was differential
Chapter 6 Solutions
Microbiology: An Introduction
Ch. 6 - Prob. 1RCh. 6 - Prob. 2RCh. 6 - Prob. 3RCh. 6 - Seven methods of measuring microbial growth were...Ch. 6 - By deep-freezing, bacteria can be stored without...Ch. 6 - A pastry chef accidentally inoculated a cream pie...Ch. 6 - Nitrogen and phosphorus added to beaches following...Ch. 6 - Differentiate complex and chemically defined...Ch. 6 - DRAW IT Draw the following growth curves for E....Ch. 6 - NAME IT A prokaryotic cell hitched a ride to Earth...
Ch. 6 - Two culture media were inoculated with four...Ch. 6 - Two culture media were inoculated with four...Ch. 6 - Use the following graph to answer questions 3 and...Ch. 6 - Use the following graph to answer questions 3 and...Ch. 6 - Assume you inoculated 100 facultatively anaerobic...Ch. 6 - The term trace elements refers to a. the elements...Ch. 6 - Which one of the following temperatures would most...Ch. 6 - Which of the following is not a characteristic of...Ch. 6 - Which of the following types of media would not be...Ch. 6 - An organism that has peroxidase and superoxide...Ch. 6 - E. coli was incubated with aeration in a nutrient...Ch. 6 - Clostridium and Streptococcus are both...Ch. 6 - Most laboratory media contain a fermentable...Ch. 6 - Flask A contains yeast cells in glucose-minimal...Ch. 6 - Clinical Applications and Evaluation 1. Assume...Ch. 6 - Heat lamps are commonly used to maintain foods at...Ch. 6 - The number of bacteria in saliva samples was...
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