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Environmental and Applied Microbiology
Dr. David Senchina, Drake University, Medical Microbio notes set 5
38
Microbiology
Undergraduate 2
02/11/2010

Additional Microbiology Flashcards

 


 

Cards

Term
What is the importance of aquatic microbiology?
Definition
Water is necessary for life
70% of the earth's surface is water
Life began, diversified, and is abundant in water (viruses too)
Term
How is life in water stratified?
Definition
By light availability
By nutrient distribution
By oxygen availability
By temperature
Term
Why is the top layer of a body of water medically significant?
Definition
Humans are more likely to come in contact with it
Term
Oxygen in water
Definition
Oxygen is NOT very water-soluble
-More abundant in upper layers
-More abundant in moving water
-More abundant in cold water
Term
Biannual turnover
Definition
In temperate regions, the movement of organisms, nutrients, and the water itself between the top and bottom of the lake as seasonal changes make the water temperature gradient change.
Term
Oligotrophic
Definition
Younger, more active bodies of water that have fewer nutrients and less dissolved organic material
Term
Eutrophic
Definition
Older, less active bodies of water that have more nutrients and dissolved organic matter. They also contain less oxygen, since more life = more things to use up oxygen.
Term
Eutrophication
Definition
The process of becoming eutrophic
Term
Red tides
Definition
In estuaries, when nutrients suddenly become more abundant, light is plentiful, oxygen is low, and the water is warm, microbes can grow and multiply at high rates.
Term
Dinoflagellates
Definition
Microbes associated with red tides.
Term
Pfiesteria piscicidia
Definition
A species of dinoflagellate that uses nerve toxin to kill and feed off fish. These toxins may also be dangerous to humans.
Term
Indicator bacteria
Definition
Normal intestinal flora or birds and mammals, used for water monitoring. They must be able to persist but not replicate in water. Includes coliforms and enteric streptococci.
Term
Coliforms
Definition
Gram-negative, lactose-fermenting, gas-producing bacteria, used for freshwater monitoring
Term
Enteric streptococci
Definition
Gram-positive bacteria that are related to (but not members of) Streptococcus spp. Used for marine monitoring.
Term
Standard plate count
Definition
A water quality assay in which a water sample is plated on medium to see how much growth there is. Does not tell us types of growth, merely amounts.
Term
Dissolved oxygen measurement
Definition
The more growth there is in the water, the less dissolved oxygen there will be.
Term
Filter coliform test
Definition
Pass a water sample through a membrane, then apply the membrane to a selective medium. Coliforms will adapt a metallic sheen, and it is possible to tell types of coliforms apart.
Term
MPN coliform test
Definition
Multiple tube fermentation - different broths are used to culture samples, and the presence of gas in a culture indicates a coliform - although we can't tell what type.
Term
MMO-MUG testing
Definition
Colorimetric test which can detect E.coli with UV exposure
Term
Acceptable level of microbes for drinking water
Definition
4 native coliforms per 100 mL
Term
Acceptable level of microbes for swimming or fishing
Definition
70-200 native coliforms per 100 mL
Term
Unacceptable water conditions
Definition
>1000 coliforms per 100mL
Term
How do we treat drinking water?
Definition
Collect, and allow to sediment. Treat with copper sulfate if being stored, and filter through sand and charcoal. Disinfect with chlorine gas, and store.
Term
How do we treat sewage?
Definition
Sedimentation
Biodegradation (let microbes eat waste)
Purification
Release into the environment
Term
How do we use microorganisms as food?
Definition
Some microorganisms are consumed directly (like kelp or mushrooms). Other microorganisms are being cultured as a source of protein to keep up with today's growing population.
Term
What is responsible for the rise of foodborne illness in the US?
Definition
Most likely, it's mass production - the larger amount that it produced, the bigger the potential for mistakes.
Term
Why aren't many cases of food poisoning reported?
Definition
Most are so mild that people either don't notice or don't bother to go to a doctor.
Term
HACCP
Definition
Hazard Analysis and Critical Control Point - food safety procedures that focus on controlling every step of the food production and storage process.
Term
How can we prevent the introduction of microbes into food?
Definition
Washing and aseptic technique (i.e. safely collecting animal products, avoiding cross-contamination, maintaining clean working areas)
Term
What does salt or sugar do to a microbe?
Definition
The microbe is plasmolyzed, because the environment is hypertonic. Enzyme activity is interfered with, and DNA structure is weakened.
Term
Dessication
Definition
Removal of moisture. Ancient, but inefficacious.
Term
Industrial microbiology
Definition
Produces compounds to be used for food, medicine, etc. Operations are large-scale, and produce a specific product through multiple, complex steps.
Term
Primary metabolites
Definition
Products of major metabolic pathways
Example: amino acids, organic acids
Term
Secondary metabolites
Definition
Byproducts of metabolism
Examples: antibiotics, steroids, vitamins
Term
How to get the most out of microbes?
Definition
Make and keep an ideal growing environment
Allow natural selection to create bacteria better suited for the process
Genetically engineer hardier or more efficient microbes
Term
Fermentor
Definition
Special vat used for mass culture in industrial microbiology. Fermentors must be able to introduce substrates and bacteria, harvest, stir, cool or heat, aerate, and monitor conditions within.
Term
Batch fermentation
Definition
All media and microbes are added together, and the batch is run to an end point, at which time the product is removed and the batch is replaced.
Term
Continuous fermentation
Definition
Media and microbes in a batch are monitored and added as needed, and the product is harvested at thresholds. The batch runs indefinitely.
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