The dense growth of algae in an algal bloom leads to increased oxygen levels in lakes that enhance the habitat for fish.
In water treatment, the purpose of flocculation is to remove microbes, such as Giardia and Cryptosporidium.
The BOD is a measurement of the amount of bacteria present before and after the sewage treatment process.
Microorganisms in deep-sea vents and caves serve as autotrophic primary producers in the absence of sunlight.
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?
The purpose of tertiary sewage treatment is to remove all of the phosphorus, nitrogen, and BOD left from secondary treatment.
Which wastewater treatment process produces BOD-containing effluent used for irrigation?
secondary sewage treatment
Which wastewater treatment process is responsible for removal of most of the BOD in sewage?
secondary sewage treatment
All of the following are true of mycorrhizae EXCEPT
the vesicular-arbuscular mycorrhizae are a type of ectomycorrhizae
The bacteriological safety of drinking water is determined by testing water samples for the presence of human pathogens.
In small communities lacking municipal sewage systems, sewage is treated in septic systems or oxidation ponds
Untreated sewage is released into a river. Which of the following statements is FALSE?
the untreated sewage kills bacteria
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.
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?
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
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?
Microorganisms play an active role in the formation of industrial products. Which of the following is mismatched?
algae- citric acid
Which of the following pertains to an improperly canned food product on a store shelf that bulges from microbial activity?
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.
Industrial canning is achieved using a pressure cooker which operates in a manner similar to an autoclave.
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 using microbial fermentations EXCEPT
If an industrial microbiologist works with Thiobacillus ferrooxidans, he is likely to be involved in copper mining.
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?
Bioreactors are widely used for industrial fermentation. Which of the following conditions must be closely monitored for optimal fermentation
temperature, pH, oxygen levels
All of the following are true of irradiation methods used for food preservation and sterilization EXCEPT
• residual radioactivity is left behind on many foods