Skip to main content
Pearson+ LogoPearson+ Logo
Ch. 5 - Microbial Metabolism
All textbooksTortora 14th EditionCh. 5 - Microbial MetabolismProblem 27.1a
Previous problem
Next problem
Chapter 5, Problem 27.1a

For questions 1–4, answer whether
a. the process takes place under aerobic conditions.
b. the process takes place under anaerobic conditions.
c. the amount of oxygen doesn’t make any difference.


Activated sludge system

Verified step by step guidance
1
Understand the activated sludge system: It is a process used in wastewater treatment involving aeration and a biological floc composed of bacteria and protozoa.
Identify the role of oxygen in the activated sludge system: Oxygen is crucial for the aerobic microorganisms to break down organic matter.
Determine the conditions under which the activated sludge system operates: The presence of oxygen is necessary for the aerobic bacteria to thrive and effectively treat the wastewater.
Consider the options provided: Evaluate whether the process is aerobic, anaerobic, or if oxygen presence is irrelevant.
Conclude based on the understanding of the process: Since the activated sludge system relies on aerobic bacteria, it operates under aerobic conditions.

Verified Solution

Video duration:
1m
This video solution was recommended by our tutors as helpful for the problem above.
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Aerobic and Anaerobic Processes

Aerobic processes require oxygen to occur, while anaerobic processes do not. In microbiology, these terms are crucial for understanding how different microorganisms metabolize substrates. For instance, aerobic bacteria thrive in environments with ample oxygen, leading to efficient breakdown of organic matter, whereas anaerobic bacteria perform fermentation or other metabolic processes in oxygen-deprived conditions.
Recommended video:
Guided course
03:35
Anaerobic Respiration

Activated Sludge System

An activated sludge system is a wastewater treatment process that uses aeration and a biological floc composed of microorganisms to degrade organic pollutants. This system typically operates under aerobic conditions, where oxygen is supplied to promote the growth of aerobic bacteria, which effectively break down waste materials. Understanding this system is essential for determining the conditions under which it operates.
Recommended video:
Guided course
02:37
Active Transport

Oxygen's Role in Microbial Metabolism

Oxygen plays a critical role in microbial metabolism, influencing the types of metabolic pathways that microorganisms can utilize. In aerobic conditions, organisms can perform cellular respiration, yielding more energy compared to anaerobic processes like fermentation. The presence or absence of oxygen can significantly affect the efficiency of waste treatment processes, such as those in activated sludge systems.
Recommended video:
Guided course
03:52
Oxygen Requirements for Microbial Growth
Previous problem
Next problem
Related Practice
Textbook Question

Suppose you inoculate three flasks of minimal salts broth with E. coli. Flask A contains

glucose. Flask B contains glucose and lactose. Flask C contains lactose. After a few hours of incubation, you test the flasks for the presence of ß-galactosidase. Which flask(s) do you predict will have this enzyme?

a. A

b. B

c. C

d. A and B

e. B and C

139
views
Textbook Question

NAME IT Use the key in the Clinical Focus box to identify the gram-negative, oxidase-positive rod causing pneumonia in a sea otter. It is H₂S-positive, indole-negative, and urease-positive.

105
views
Textbook Question

Unlike purple and green phototrophic bacteria, cyanobacteria

a. produce oxygen during photosynthesis.

b. do not require light.

c. use H₂S as an electron donor.

d. have a membrane-enclosed nucleus.

e. all of the above

122
views
Textbook Question

For questions 1–4, answer whether

a. the process takes place under aerobic conditions.

b. the process takes place under anaerobic conditions.

c. the amount of oxygen doesn’t make any difference.


Denitrification

105
views
Textbook Question

In the sulfur cycle, microbes degrade organic sulfur compounds, such as (a) _________________, to release H₂S, which can be oxidized by Acidithiobacillus to (b) _________________. This ion can be assimilated into amino acids by (c) _________________ or reduced by Desulfovibrio to (d) _________________. H₂S is used by photoautotrophic bacteria as an electron donor to synthesize (e) _________________. The sulfur-containing by-product of this metabolism is (f) _________________.

130
views
Textbook Question

For questions 1–4, answer whether

a. the process takes place under aerobic conditions.

b. the process takes place under anaerobic conditions.

c. the amount of oxygen doesn’t make any difference.


Nitrogen fixation

104
views