Biogeochemical Cycling 1
These microorganisms are capable of nitrogen fixation? (Hint: Domains)
What are Bacteria and Archaea?
Nitrate and nitrite are reduced to N₂ gas by facultative anaerobes in this nitrogen cycle process.
What is Denitrification?
To ensure an accurate BOD measurement, samples must be incubated for five days in the dark to prevent this biological process from producing new oxygen.
What is photosynthesis?
This type of light is a commonly used disinfectant
What is UV (ultraviolet)?
This common food preservation method involves heating a liquid to a specific temperature to reduce the number of microbes without necessarily sterilizing the product.
What is pasteurization?
The electron donor in anoxygenic photosynthesis
What is H2S?
Reason O2 is irreversibly destroyed by nitrogenase
What is higher electronegativity/better electron acceptor?
Abbreviated as BOD, this is the amount of dissolved oxygen required by microbes to decompose the organic matter remaining in the water
What is Biochemical Oxygen Demand?
This initial stage of drinking water treatment involves adding chemical coagulants to aggregate small particles into larger clumps called flocs.
What are coagulation and flocculation?
Unlike non-ionizing UV radiation which only affects surfaces, these two types of ionizing radiation are stronger and can penetrate deep into food to damage microbial DNA.
What are gamma rays and X-rays?
Organism that provide H2 for methanogens
What is ethanol-fermenting syntrophs?
Location of lake methanogens
What is a Thermocline?
The three goals of wastewater treatment
What are:
1. Remove or kill/inactivate harmful microbes
2. Lower total organic carbo (TOC)
3. Lower inorganic nutrients (ammonium, nitrate, phosphates)
?
This specific hepatotoxin is the only cyanobacterial toxin currently regulated in treated drinking water in Canada, with a maximum allowable limit of 1.5 µg/L.
What is microcystin?
This food preservation strategy, known as hurdle technology, involves combining multiple antimicrobial controls to provide better protection than any single method alone.
What is hurdle technology?
The movement of nitrogen from NO₃⁻in the soil to N2 gas by denitrification
What is Flux?
In remineralization, this happens to the electron in organic carbon during mineralization
What is loss of electron?
While Vibrio cholerae is a bacterial pathogen found in feces, Giardia, Cyclospora, and Cryptosporidium represent this category. (Hint: Think Generally)
What are harmful eukaryotic microbes?
Unlike microcystin, this neurotoxin cannot be effectively removed using chlorine and typically requires advanced treatment methods like ozonation (O3).
What is anatoxin?
Because its spores are resistant to boiling and it thrives in low-acid, anaerobic environments, this bacterium is a major risk in improperly canned foods.
What is Clostridium botulinum?
The source of human N2 fixers that drastically increase the projected fixed nitrogen levels
What is Haber-Bosch process?
Fermenting microbes need methanogens to perform this function so fermentation reaction can continue.
What is Reduce H+ Concentration?
Excessive nitrogen and phosphorus in released wastewater can trigger this process, leading to algal blooms and oxygen-depleted "dead zones"
What is eutrophication?
This common chemical disinfectant works by destroying DNA structures, changing cell membrane permeability, and obstructing the catalytic action of enzymes within harmful microbes.
What is chlorine?
This industrial vessel allows for the continuous addition of fresh medium and removal of old culture to maintain a microbial population in a specific phase of growth
What is a chemostat?