Question 1

Which of the following is an example of an extremozyme?&#10;A) a microorganism that is isolated from a very hot, thermal pool of water&#10;B) the Taq polymerase, isolated from Thermus aquaticus, which is used in PCR&#10;C) a cellulase enzyme, which can digest cellulose, used in a stain remover&#10;D) a biopesticide used to control insect pests in the garden&#10;E) a microorganism used in nanotechnology

Accepted Answer

Extremozymes are enzymes that are able to function under extreme conditions, such as high temperature, extreme pH, or high pressure. Taq polymerase, isolated from the bacterium Thermus aquaticus that lives in hot springs, is an example of an extremozyme because it can withstand the high temperatures needed for PCR reactions.

Question 2

Some bacteria release electrons, which can then be bound to an electrode, generating electricity. This process may be used:&#10;A) to produce cellulosic ethanol.&#10;B) to produce biodegradable plastics.&#10;C) to create microbial fuel cells.&#10;D) to separate valuable minerals from rock deposits.&#10;E) as a biologically produced hydrocarbon.

Accepted Answer

This process is known as microbial fuel cells, where bacteria use organic matter to produce electrons, which can be harnessed to generate electricity. This can be used as a sustainable source of energy.

Question 3

If bacteria that have undergone strain improvement are introduced into a natural environment:&#10;A) they will usually outcompete and replace naturally occurring, wild-type strains.&#10;B) they will usually be outcompeted by naturally occurring wild-type strains.&#10;C) they will usually act as predators on naturally occurring wild-type strains.&#10;D) they will usually serve as prey for naturally occurring wild-type strains.&#10;E) they will usually act as commensals with naturally occurring, wild-type strains.

Accepted Answer

Naturally occurring wild-type strains are adapted to the natural environment, whereas bacteria that have undergone strain improvement may have been optimized for growth in specific laboratory conditions. Therefore, the wild-type strains will usually outcompete the improved strains in the natural environment.

Question 4

Why does compost tend to heat up over time? Why is it beneficial to periodically turn the compost?

Accepted Answer

The answer of Why does compost tend to heat up...

Question 5

Which of the following statements about landfills is true?&#10;A) Decomposition of garbage is slowed by anaerobic conditions.&#10;B) Decomposition of garbage is slowed by aerobic conditions.&#10;C) Decomposition of garbage is slowed by toxic chemicals, which kill microorganisms.&#10;D) Decompostion of garbage is slowed by the release of methane.

Accepted Answer

Landfills are typically designed to create anaerobic conditions, meaning there is very little oxygen present. This slows the natural process of decomposition, as aerobic bacteria require oxygen to break down organic matter. Anaerobic bacteria do eventually break down organic matter in a landfill, but at a much slower rate than aerobic bacteria.

Question 6

Microorganisms to be used commercially usually are developed in a series of defined steps. Which of the following has those steps in the correct order?&#10;A) laboratory flask &#187; pilot plant fermentor &#187; laboratory fermentor &#187; industrial fermentor&#10;B) laboratory fermentor &#187; laboratory flask &#187; pilot plant fermentor &#187; industrial fermentor&#10;C) industrial fermentor &#187; pilot plant fermentor &#187; laboratory fermentor &#187; labortory flask&#10;D) laboratory flask &#187; laboratory fermentor &#187; pilot plant fermentor &#187; industrial fermentor&#10;E) pilot plant fermentor &#187; labortory flask &#187; industrial fermentor &#187; laboratory fermentor

Accepted Answer

The correct order for developing microorganisms commercially is laboratory flask » laboratory fermentor » pilot plant fermentor » industrial fermentor. This order allows for gradual scaling up and optimization of the growth conditions for the microorganism before reaching industrial-scale production. Choice D is the only option that has this order.

Question 7

Metabolites are:&#10;A) the substrate that is converted into a useful product by microorganisms.&#10;B) an intermediate compound in a biochemical pathway, the final product of which is a useful product.&#10;C) the final product in a biochemical pathway.&#10;D) either &#34;a&#34; or &#34;c&#34; above&#10;E) either &#34;b&#34; or &#34;c&#34; above

Accepted Answer

Metabolites are intermediate compounds in biochemical pathways that can be further metabolized to a final product. They are not necessarily the final product themselves, but can be the substrate for the next step in the pathway. Therefore, both option "b" and option "c" are correct. However, option "a" is not accurate as metabolites are not converted into useful products by microorganisms.

Question 8

The easiest step when it comes to developing a new antibiotic is:&#10;A) finding a microorganism that produces an antibiotic.&#10;B) determining the optimum growth conditions for the microorganism in question.&#10;C) the scale-up process.&#10;D) improving the bacterial strain so that commercially valuable quantities of the antibiotic are produced.

Accepted Answer

Finding a microorganism that produces an antibiotic is the easiest step because it only requires searching for existing microorganisms that produce antibiotics and testing their effectiveness. The other steps involve more complex processes such as scaling up production and improving the bacterial strain, which can be more challenging and time-consuming.

Question 9

Which type of organism would be most promising if you were seeking an organism that can digest hydrocarbons, to help clean up oil spills?&#10;A) a nonfastidious organism&#10;B) a fastidious organism&#10;C) an obligate anaerobe&#10;D) an extreme thermophile&#10;E) an acidophile

Accepted Answer

A nonfastidious organism would be the most promising as it is adaptable to a wide range of environmental conditions, including those found in oil spills. Fastidious organisms have specific nutritional requirements and may not be able to survive in such an environment. Obligate anaerobes require a low-oxygen environment, which may not be present in oil spills. Extreme thermophiles and acidophiles thrive in high temperatures and low pH, respectively, but oil spills may not provide suitable conditions for their survival.

Question 10

When bacteria are used in wastewater treatment plants to convert hydrogen sulfide into hydrogen sulfate, why are the bacteria grown on biofilms?&#10;A) To protect them from damage to their cell walls caused by the waste water.&#10;B) The bacteria that make this conversion can only grow in biofilms.&#10;C) The biofilms increase the time during which the bacteria can metabolize the hydrogen sulfide.&#10;D) The hydrogen sulfate adheres to the biofilm, reducing the amount of this chemical released in treated water.&#10;E) Only bacteria growing in biofilms produce the enzyme necessary to make this conversion.

Accepted Answer

Biofilms increase the residence time of the bacteria, allowing them to metabolize hydrogen sulfide for a longer period. This enhances the overall efficiency of the wastewater treatment process.

Question 11

What exactly is the biopesticide Bt? Why is this product, which kills garden pests, not a danger to humans, pets, or other animals?

Accepted Answer

The answer of What exactly is the biopesticide Bt? Why...

Question 12

Which of the following statements about primary and secondary metabolites is true?&#10;A) Primary metabolites are produced maximally during the lag phase of growth.&#10;B) Secondary metabolites are produced maximally during the lag phase of growth.&#10;C) Primary metabolites are produced maximally during the log phase of growth.&#10;D) Secondary metabolites are produced maximally during the log phase of growth.&#10;E) Primary metabolites are produced maximally during the stationary phase of growth.

Accepted Answer

The answer of Which of the following statements about primary...

Question 13

In what way does metabolite production by a microorganism often depend on other microorganisms that may be found in the same environment?

Accepted Answer

The answer of In what way does metabolite production by...

Deck 16: Better Living With Microorganisms: Industrial and Applied Microbiology