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83 terms

Micro Test 2

STUDY
PLAY
All of the following are used in secondary sewage treatment EXCEPT
anaerobic digestion
The dense growth of algae in an algal bloom leads to increased oxygen levels in lakes that enhance the habitat for fish.
false
Residual chlorine must be maintained in
water treatment
All of the following organisms are involved in carbon fixation EXCEPT
mycorrhizae
In water treatment, the purpose of flocculation is to remove microbes, such as Giardia and Cryptosporidium.
false
The BOD is a measurement of the amount of bacteria present before and after the sewage treatment process.
false
Which of the following requires aerobic conditions?
secondary sewage treatment
sedimentation of sludge occurs in
primary treatment
The water from tertiary sewage treatment can be used as drinking water.
true
Bioremediation involves the use of microbes to degrade or detoxify pollutants.
true
Which of the following organisms is using sulfur as a source of energy?
Thiobacillus
Microorganisms in deep-sea vents and caves serve as autotrophic primary producers in the absence of sunlight.
true
Nitrogen fixation by bacteria occurs only in the root nodules of leguminous plants.
false
Biochemical oxygen demand is a measure of the
amount of organic matter present in a water sample
Which stage of sewage treatment produces methane
Sludge digestion
Which one of the following processes in sewage treatment requires bacterial metabolism?
removal of BOD
For the biogeochemical cycles of the following elements, which does NOT have an atmospheric cycle?
phosphorus
Drinking water supplies are routinely tested for the presence of
fecal coliforms
Aerobic respiration occurs in
secondary sewage treatment
The purpose of tertiary sewage treatment is to remove all of the phosphorus, nitrogen, and BOD left from secondary treatment.
true
Bioremediation of petroleum
takes place under aerobic conditions
Which wastewater treatment process produces BOD-containing effluent used for irrigation?
secondary sewage treatment
NH3 → NO2-
takes place under aerobic condiditons
Adding untreated sewage to a freshwater lake would cause the biochemical oxygen demand to
increase
All of the following are habitats for extremophiles EXCEPT
the atlantic ocean
6H2S + 6CO2 6S0 + glucose
takes place under anaerobic conditions
Which of the following is required for composting
periodic turning of the cmpost pile
Which wastewater treatment process is responsible for removal of most of the BOD in sewage?
secondary sewage treatment
Which of the following terms describes NO3- NO2- → N2O → N2?
denitrification
The release of phosphate-containing detergents into a river would
increase algal growth
All of the following are true of mycorrhizae EXCEPT
the vesicular-arbuscular mycorrhizae are a type of ectomycorrhizae
Bacteria can increase the Earth's temperature by
producing ch4 which is a greenhouse gas
The bacteriological safety of drinking water is determined by testing water samples for the presence of human pathogens.
false
Which of the following is an assimilation process?
• Redwood tree: SO42- → Amino acids
Which of the following is NOT a symbiotic pair of organisms?
sulfur and thiobacillus
In small communities lacking municipal sewage systems, sewage is treated in septic systems or oxidation ponds
true
Which of the following do NOT fix atmospheric nitrogen
mycorrhizae
Untreated sewage is released into a river. Which of the following statements is FALSE?
the untreated sewage kills bacteria
Which of the following is NOT characteristic of fecal coliforms?
pathogenic
Filtration to remove protozoa occurs in
water treatment
Thiobacillus ferrooxidans is used for the recovery of _________ from ore.
Copper
Radiation works to preserve foods through
Lethal mutation of bacterial DNA
What role do lactic acid bacteria play in cheese production?
• Lactic acid bacteria carry out each of these roles in cheese production.
Commercial sterilization differs from complete sterilization in that commercial sterilization
• may result in the survival of thermophiles.
High-pressure processing of foods such as deli meats and precooked chicken strips targets pathogens such as C. botulinum.
false
Xanthan used in household products is produced by bacteria
• selected for their ability to utilize lactose and that are plant pathogens
Commercial sterilization of processed canned foods uses a 12D treatment which is based upon a theoretical population of 1012 C. botulinum endospores in a can of food. After treatment, there would theoretically be how many endospores left?
1 endospore
You are growing Bacillus subtilis in a bioreactor and notice that the growth rate has slowed and the pH has decreased. You suspect the bacteria are
fermenting
Vitamins A, B12, and E are commonly produced by microorganisms
false
All of the following are reasons for utilizing algae for biofuel production EXCEPT
• they produce a nondegradable waste product
Spoilage of canned foods due to inadequate processing, NOT accompanied by gas production, is
flat sour spoilage
A baker forgets to put yeast in his bread dough. Which of the following do you expect to happen to the bread as a result?
bread wont rise
Which of the following microorganisms is usually used in the fermentation of alcoholic beverages?
saccharomyces
Microorganisms play an active role in the formation of industrial products. Which of the following is mismatched?
algae- citric acid
Which of the following microbes produces a natural biopesticide
bacullus thuringiensis
Which of the following is an undesirable contaminant in wine-making?
acetobacter
Which of the following pertains to an improperly canned food product on a store shelf that bulges from microbial activity?
Mesophilic spoilage
The blue-green clumps observed in Roquefort cheese are a result of mold growth
true
Which of the following reactions is performed by yeast in wine-making?
• sugar → ethanol
Spoilage of canned foods stored at high temperatures, accompanied by gas production, is
• thermophilic anaerobic spoilage
Aseptic packaging utilizes which of the following to sterilize laminated paper or plastic prior to filling with food?
• hot hydrogen peroxide solution
The longer interior-ripened cheeses are permitted to ripen, the milder the taste of the cheese.
false
Industrial canning is achieved using a pressure cooker which operates in a manner similar to an autoclave.
false
All of the following are advantages of a bioreactor instead of a flask culture EXCEPT
• None of the answers is correct; all of these are advantages of using a bioreactor instead of a flask culture
The following steps are required for making cheese. What is the second step
inoculation with lactic acid bacteria
All of the following are industrial products produced by microbes EXCEPT
uranium
canning preserves food
• by exposure to high heat.
Rhizobium and Bradyrhizobium are mixed with peat moss to increase nitrogen fixation.
true
All of the following are industrial products produced using microbial fermentations EXCEPT
saccharin
A large industry exists based on the synthesis of amino acids by microorganisms.
true
Canning works to preserve foods through
creation of anaerobic environment and high heat
What process does yeast use to produce ethanol for automobile fuel from corn?
fermentation
If an industrial microbiologist works with Thiobacillus ferrooxidans, he is likely to be involved in copper mining.
true
Aeptic packaging works to preserve foods through
exposure to high heat
You are growing Bacillus subtilis in a bioreactor and notice that the growth rate has slowed and the pH has decreased. What could you add?
oxygen
Bioreactors are widely used for industrial fermentation. Which of the following conditions must be closely monitored for optimal fermentation
temperature, pH, oxygen levels
Microbial products can be improved by all of the following EXCEPT
sterilization
Mesophilic bacteria grow best at temperatures of 60°C.
false
All of the following foods are produced using microbial fermentations EXCEPT
ketchup
Which of the following pairs is mismatched?
bacillus beer
All of the following are true of irradiation methods used for food preservation and sterilization EXCEPT
• residual radioactivity is left behind on many foods
All of the following are fuels produced by microorganisms EXCEPT
cellulose
Biomass is a renewable energy source derived from the organic matter produced by living organisms. All of the following are sources of biomass EXCEPT
oxidation of metals