Microbiology of water Flashcards
On what does biological activity of an aquatic system ultimaly depends on?
activity of primary producers
What is phytoplankton ?
Algae, that with carbon source, will be a source of food for organisms (chemoheterotrophs)
On what factors does phytoplankton and other organsims activity depends on?
- Temperature
- Light received
- Availability of specific limiting nutrients such as nitrogen and phosphorus
On what does the photic zone depend on?
On turbidity of the water…
How will the microorgansisms in deeper water have to harvest light?
Phycobillins and Chlorosomes ( huge protein attennea that you find in green bacteria)
In marine environment, concentration of salt is ___, so organisms are _____.
3%
Halotolerant
75% of the ocean is deeper than _____. Deep sea is also called ____.
1000m
Pelagic zone
Under 100m, the temperature is constant ( ____ degrees). Organisms living there are mostly _____ or ______.
2-3 degrees
Psychrophiles, psychrotolerant
The open ocean (does or doesn’t) have a low primary activity. Open ocean is a ___________ environment .
Does
OLIGOTROPHIC
What does Oligotrophic mean? What environment is oligotrophic?
Low in nutrients, because low primary productivity
Open oceans a
What are protochlorophytes, where are they found? give an exemple
Primary producers. Tiny phototrophs phylogenically related to cyanobacteria. They are found in open ocean.
Prochlorococcus
What are general adaptation seen in pelagic microorganisms?
- Reduced size (high surface/volume ration)
- This is energy favorable - High affinity transport system (so can capt nutrients in a poor nutrients environment )
Who am I?
- Filamentous cyanobacteria
- Contain phycobillins
- nitrogen fixer
Trichodesmium
What are the main primary producer in coastal water?
Algae and cyanobacteria
How is productivity higher in coastal water?
Influx of nutrients form rivers and other polluted water source
What does eutrophic mean?
High in primary productivity, rich in nutrients
Coastal water is eutrophic or oligotrophic?
Eutrophic
What nutrient is limiting in coastal water?
Nitrogen
What is a negative thing that can happen in coastal water?
Red tides ( algal bloom, dinoflagellates, neurotoxins)
What are the characteristics of deep sea ( below 1000m)? what organisms are found there?
Organic carbon is very scarce Oligotrophic environment No light Very few microorganisms - Psychrophilic, barophilic, barotolerant
What is an example of protist found in deep sea?
Xenophyophore, large protist related to psalmodial slime mold
What do hydrothermal vent provide?
- Heat
- source of nutrients
- Source of electron donors
- Source of electron acceptors (ex sulfur)
Exemple of symbiotic relationship in hydrothermal vent environment?
Tube worms that live in symbiosis with oxidizing chemoautotrophs
Tue worms trap and transport nutrients to the bacterial symbionts
What are the limiting nutrient in freshwater environment?
Nitrogen and phosphorus
What is the difference between lakes and rivers?
Lake= poor mixing, aeration Rivers= good mixing, aeration
What are characteristics of oligotrophic lakes?
- N and P are limiting nutrients
- Primary production is low
- Availability of organic matter is low
- Growth of chemoheterotrophs is limited
- Lake remains AEROBIC
- Oxygen is saturated
- Clear water, deep penetration of light
What are characteristics of eutrophic lakes?
- Primary production is high (algal bloom)
- Availability of organic matter is high
- rapid growth of cheoheteroptrophs
- Rapid DEPLETION of OXYGEN
- Low oxygen concentration
- Anaerobic sones are created
- Poor light penetration
- heath risk- pathogens, bloom of cyanobacteria/algea that secrete toxins
What is produced anaerobically that is toxic for plants? What produces it?
Sulfide, sulfur reducers
How do we call phenomenon when different temperature at different levels in lakes?
Stratification
When does stratification happen?
During summer and winter, because there is a difference of temperature at the surface and bottom…
How is called the upper layor in stratification of lake water? whate are the characteristics of this layor?
Epilimnion
- warmer than bottom layor
- less dense
- aerobic
How is called the bottom layor in lake water stratification? characteristics?
Hypolimnion
- denser
- colder
- anaerobic
How is called the zone in the middle in stratification of lake water?
Thermocline zone
- it is a zone of rapid temperature change
What is the difference of river vs lakes?
River have a good mixing/aeration , that ensures that organic matter (within limits) is degraded effecively (no fermentaion, no H2S production)
More tolerant to pollution
Can rivers still be eutrophic?
Yes (not totally…), excess organic matter may still result in anaerobiosis with consequences similar to those in eutrophic lakes
What is the major source of pollution of freshwater? how does it happen?
Sewage
Deliberate discharge of effluents into a waterway
What is the definition of BOD? what does it do?
Biochemical oxygen demand
It is used as a measure of the extent of pollution
The higher the BOD is (the fastest the oxygen is consumed) the more pollution there is. It correlates with how much nutrients there is available
What is a biofilm? What is made of?
Microbial cells embedded inside an extracellular matrix.
The matrix is composed of proteins, polysaccharides, DNA
It will grow as a multicellular organisims, you can have release of organism that will grow somewhere else
Are biofilm made of only one specy?
No, mixed population of species
where do we find biofilm?
in water systems ( natural or man-made) , on wet surfaces, growing on medical devices etc.
Where do water born pathogens come from?
Most of these pathogens grow in the intestinal tract and transmission is mediated by fecal contamination of water supplies
What are the 2 sources of infection?
- Potable water (drinking and food preparation)
- Recreational water (swimming)
What are some water-borne bacterial pathogens and viruses?
GIARDIA LAMBIA (beaver fever) - Causes giardiasis. Often associated with drinking water in wilderness areas. Chronic diarrhea
CRYPTOSPORIDIUM PARVUM
-chronic accute diarrhea, self limiting in healthy individuals, major problem in immunocompromised induvuduals. Present in 90% of sewage samples, 75% river waters and 28% of drinking water
- Salmonella typhi-> typhoid fever
- Vibrio cholerae-> cholera, severe diarrhea
- Shigella spp.
- Salmonella spp.
- Campylobacter spp. - gastroenteritis
- Enterovirus - polliovirus, rotavirus
- Hepatitis A virus
- Entamoeba histolytica
What is special about G.lamblia and C. parvum?
They produce cyst that are resistant to a number of desinfectants, including chlorine.
C.parvum cyst are really small, cannot be remove effectively by filtration process of water.
How do we test if water is safe for human consumption? Is it possible to check for all pathogens?
Impossible to check for all pathogens.
Most water borne pathogens are associated with fecal material.
Test water for organisms thart are present in large numbers in feces! (fecal pollution)
If these organisms are present, there is a chance that the water may also be contaminated by pathogens
What are the 2 indicators for water test?
- Test for coliforms
- Test for fecal coliforms