7. Microbiology - Water Flashcards
(34 cards)
- the biological activity of an aquatic ecosystem depends on ____A______? give 2 examples
- these ____A_____ serve as a ______ source for chemoheterotrophs (bacteria, protozoa, zooplankton), fish, other aquatic organisms
the activities and net numbers of phytoplankton depend on (3)
- depends on primary producers! (photoautotrophs, phytoplankton) –> can do carbon fixation! ie algae and cyanobacteria!
*cyanobacteria = very good for ecosystem bc source of food for other microorgs BUT if grow uncontrollably = bad - primary produces serve as food source for chemoheterotrophs…
- temperature
- light received
- availability of specific limiting nutrients like Nitrogen and Phosphorus (in water) –> typically this that limits growth of microorgs (vs temp and light)
what is the photic zone?
- open ocean vs coastal waters
PHOTIC ZONE
- zone/depth of water colum where light can penetrate!
- in clear water, can penetrate to a maximum depth of 300m
- best for metabolic diversity
*microorgs must be able to harvest light that reaches them (accessory pigments)
OPEAN OCEAN:
- when water is clear: light can go until 200-300m –> red on goes a few meters, blue can go very deep, that’s why ocean we see is blue
COASTAL WATERS:
- close to the coast: lots of particles: rain from land carry particles to sea
- best case scenario: 50m deep of photic zone
MARINE ENVIRONMENT
- high/low salinity? means that which orgs can live there?
- ____% of ocean is deeper than 1000m –> deep sea = ________ ZONE
- at the ocean’s deepest (_____ km below surface) –> pressure is about ____ atm
- below 100m, temperature is constant at ___-____°C –> what type of orgs can survive there?
- high salinity (3%) –> halotolerant or halophile
- 75% –> deep sea = PELAGIC zone
- 11km below surface –> 1100 atm (bc 1 atm/10 m ish)
- 2-3°C –> psychrophiles (fridge temps)
OPEN OCEAN
- in the pelagic zone, primary productivity is very high/low due to WHAT
- SO, open ocean is _______trophic
- temperatures are hotter/cooler and more/less constant than in area closer to shore
- in some regions, what can happen –> promotes/decreases productivity
- measure concentration of what to measure productivity?
- very LOW due to lack of inorganic nutrients (nitrogen, phosphorus, iron) that are required by phytoplankton
- OLIGOTROPHIC (ocean desert)
- cooler and more constant than shore
- wind and ocean currents cause an upwelling of water from ocean floor bringing nutrients to surface/water column and promoting productivity
*ie gulf stream and labrador current near nova scotia and newfoundland –> sediments at -200m are brought back to surface! = more microorgs = more fish! - concentration of chlorophyll! marker of photosynthesis
OPEN OCEAN:
- bulk of primary productivity comes from _________________ –> describe. example?
- general adaptations seen in pelagic (open ocean) microorgs: (2)
- trichodesmium –> does 3 things/adaptations
- from prochlorophytes –> tiny phototrophs phylogenetically related to cyanobacteria –> prochlorococcus (filaments!)
1) reduced size (high surface/volume ratio)
2) high affinity transport systems (ie ABC transport)
TRICHODESMIUM (type of prochlorophyte?)
- filamentous cyanobacteria
- contains phycobilins: to harvest as much light as possible
- nitrogen fixation
COASTAL WATER:
- primary producers: (2)
- productivity is usually higher/lower due to WHAT
- so, coastal water is _______trophic
- can cause _____ _________
- what is a limiting nutrient
- higher/lower level of primary productivity supports WHAT
- algae, cyanobacteria
- higher due to influx of nutrients from rivers and other polluted water sources (ie agricultural runoff (cause excess nitrogen and phosphorus) + sewages)
*very shallow: mix of water will bring back sediments into the water column/photic zone = lots of nutrients - EUTROPHIC! = very rich in nutrients
- can cause red tides (algal bloom, dinoflagellates, neurotoxins)
- nitrogen is a limiting nutrient
- higher level of primary productivity supports a higher concentration of zooplankton and aquatic animals
DEEP SEA:
- WHAT zone?
- depth: between ____ and ____m
- temp?
- which type of orgs (like chemo/photo hetero/auto troph) degrade organic/inorganic matter that fall from WHAT?
BELOW 1000m:
- what is very scarce –> _______trophic
- light?
- what types of microorgs are there?
is there life at > 10 000m?
DEEP SEA:
- pelagic zone
- 300 to 1000m, still some O2 though
- 2-3°C –> psychrophiles
- chemoheterotrophs degrade organic matter that falls from the photic zones (ie a whale that dies)
BELOW 1000:
- organic carbon is very scarce –> oligotrophic
- no light
- very few microorg (psychrophilic + barophilic or barotolerant)
yes! we don’t understand it at all though
HYDROTHERMAL VENT
- source of (4)
- do microorgs and animals live around it? around what?
- tube worms: symbiosis with what? explain
*hydrothermal vents = exceptions ish –> very deep but:
- source of heat, nutrients, electron donor and electron acceptors
- communities of microorgs (microbial mats) and animals live around the CHIMNEY
TUBE WORMS: symbiosis with sulfur oxidizing chemoautotrophs
- tube worms trap and transport nutrients to the bacterial symbionts, which supplies the worm with organic material
*bacteria supplies worm with organic material
FRESHWATER ENVIRONMENT:
- highly variable/constant –> why?
- microbial populations depend on (3)
- 2 types ish: good or bad mising/aeration
- highly variable! isolated system compared to ocean bc they are ISOLATED!
1) availability of nutrients –> limited by the availability of nitrogen and phosphorus!
2) availability of light
3) availability of oxygen
1) lakes: POOR mixing/aeration: no waves, no current, no mixing down water column
2) rivers: GOOD mixing/aeration –> more O2 going in water
*but some rivers/lakes are oligotrophic: very few nutrients, very clear, can see bottom, not many microorgs
OLIGOTROPHIC LAKES
- which 2 substances are limiting?
- primary production is high/low, availability of organic matter is high/low
- growth of aerobic/anaerobic _____________ is limited by WHAT
- oxygen concentration remains high/low
- rate of oxygen dissolution is higher/lower than consumption rate
- lake remains aerobic/anaerobic even at depth, and organic matter is _____________ completely
- oxygen depleted/saturated
- clear/dark water
- N and P!
- low and low!
- aerobic chemoheterotrophs is limited by nutrient supply!
- O2 concentrations remain high!
- rate of O2 dissolution is HIGHER than consumption rate!
- remains aerobic even at depth and org matter is degraded completely
- oxygen SATURATED (ie good for fish)
- clear water –> deep penetration of light
smells good, super clean
*as soon as there’s some organic matter (ie rabbit pees in it), all the organic carbon is fully oxidized by chemotrophs
EUTROPHIC LAKE
- primary production is high/low, availability of organic matter is high/low
- rapid growth of _______________, rapid depletion of what?
- low/high concentrations of O2
- rate of oxygen dissolution is higher/lower than consumption rate
- aerobic/anaerobic zones created
- deep/poor light penetration
- health risk? (2)
- high and high!
- rapid growth of chemoheterotrophs, rapid DEPLETION of dissolved oxygen
- LOW O2 concentrations
- rate of O2 dissolution is lower than rate of consumption!
- ANAEROBIC zones are created –> so microorgs do anaerobic resp + fermentation –> produce bad smells
- POOR light penetration
- pathogens + bloom of cyanobacteria/algae (secrete toxins)
EUTROPHIC LAKE:
- bottom sediments are aerobic/anaerobic and contain organic/inorganic matter (ex) which support growth of (3)
- anaerobic/aerobic photosynthesis uses WHAT as electron donor and produces WHAT, which is used by WHO
- excessive production of WHAT and production of WHAT from _____________ can give water a bad odor
- what (2) may kill fish and other aerobic organisms?
- ANAEROBIC + contain ORGANIC matter (ie dead primary producers, etc.) which support growth of denitrifiers, methanogens and sulfate reducers (produce sulfide! H2S)
- ANAEROBIC photosynthesis uses H2S as e- donor and produces sulfate which is used by SULFATE REDUCERS
- excessive production of H2S and the production of organic acids from fermentation can give water bad odor
- lack of O2 and/or presence of H2S may kill fish and other aerobic organisms
LAKES IN TEMPERATE CLIMATES:
- anaerobic/aerobic zones may develop as a result of WHAT –> lakes become __________ stratified
- describe the 4 stages
- when is there mixing?
anaerobic zones may develop as a result of summer stratification! lakes become thermally stratified
1. WINTER: ice on top, 4°C water = most dense –> go to the bottom, crust of earth heats up bottom water ish to 4°C
2. SPRING TURNOVER as ice melts, ice goes down water column and warmer water goes up = mixing!
3. SUMMER STRATIFICATION: as air temp increases, surface water is warmed = formation of a warm upper layer (epilimnion) –> much less dense than 4° water + O2 = aerobic respiration VS bottom layer (hypolimnion) = more dense, anaerobic
*epilimnion and hypolimnion are separated from each other by a zone of rapid temperature change: thermocline
4. FALL TURNOVER: top layer cools down to the same temp as bottom layer –> mixes stuff up: mixing brings back nutrients up water column + rings O2 down water column
*mixing only in the spring and fall! brings nutrients back up the water column
RIVERS:
- good or bad aeration and mixing?
- ensures that WHAT is degraded effectively?
- is there fermentation and H2S production?
- excess organic matter may still result in ___________ with consequences similar to those seen in ___________ lake
- good!!!
- ensures that organic matter, within limits, is degraded effectively! –> more tolerant to organic matter bc mixing = less accumulation of toxins
- no fermentation or H2S production –> more diffusion of O2
- may still result in anaerobiosis with consequences similar to those seen in eutrophic lakes
*more resistant to atrophication (?)
POLLUTION
- define pollution of freshwater
- major source? –>describe that source
- ________ & ________ organisms reduce/oxidize organic matter using WHAT
- what is BOD –> used as a measure of what?
- deliberate discharge of effluents into a waterway
- SEWAGE! rich in organic matter (fecal, urine, soap, food) and contins a large number of organisms (may contain pathogens!)
- aerobic and facultative organisms OXIDIZE org matter using dissolved oxygen
- Biochemical oxygen demand –> used as a measure of the extent of pollution by organic matter + measure of metabolic activity/amount of O2 consumed by orgs
ie high BOD = lots of chemoorganotrophs that burn nutrients through aerobic respiration
what happens to
a) O2
b) bacteria, organic C and BOD
c) algae and cyanobacteria
d) NO3-
e) NH4+ and PO4^3-
as distance downstream of sewage increases
- normal water:
- normal O2
- low b,c,d,e - input: sewage, other waste-waters
- O2 starts to decrease, and reaches a very low level as b) peaks
- bacteria, organic C, BOD increases! reaches peak!
- c) decreases a little
- d) and e) increase - further downstream:
- increase in algae and cyanobacteria
decrease in b), d) and e) bc MORE DILUTION with time and distance
- bc b, d and e decrease, O2 goes back to normal levels
BIOFILM
- define
- usually produced by a single or a mix of species?
- extracellular matrix composed of (3)
- cells inside biofilm are resistant?
- biofilms are found where (4)
- Biofilm: microbial cells embedded inside an extracellular matrix
- Usually produced by a mixed population of species. –> multispecies!
- composed of proteins, polysaccharides, DNA (holds everything together)
- Cells inside the biofilm are more resistant to stresses than planktonic (free-living) cells –> ECM acts a bit like a capsule! protects against predation, desinfectant, mechanical stress
- water systems (natural and man-made) (ie clogging of water pipe, biofouling of a ship full)
- on wet surfaces (ie shower, pink stuff)
- growing on medical devices (can be source of infection = bad)
- can grow on surface of river! = microbial mat in river
WATER-BORNE PATHOGENS
- most of these pathogens grow WHERE and how are they transmitted to humans?
- sources of infection (2) –> increasing or decrease throughout the years?
- grow in intestinal tract of animals! – transmission is mediated by fecal contamination of water supplies/bodies –> if humans drink that water = can acquire pathogen = bad
*fecal - oral route
1) potable water: drinking and food prep (ie wash veg)
- decreasing throughout the years –> better at making water safe
2) recreational water: swimming, water skiing, canoeing…
- increasing throughout years –> bc more water being contaminated by sewage/waste
give examples of water-borne BACTERIAL pathogens (5) and VIRUS (2)
- Salmonella spp. (other than typhi): salmonellosis, gastroenteritis –> localized diarrhea
- Salmonella typhi: typhoid fever in humans, healthy carriers –> NOT localized –> systemic infection = more lethal!
- Vibrio cholerae: cholera, severe diarrhea (enterotoxin) –> can lose 20L per day
- Shigella spp.: shigellosis; bacterial dysentery (bloody diarrhea, inflammation of the intestinal mucosa) –> GI infection
- Campylobacter spp.: gastroenteritis, most common cause of gastroenteritis in
Canada. - Enterovirus: poliovirus, norovirus, rotavirus (children) –> very contagious, cruise ships!
- Hepatitis A virus.
give examples of water-born pathogenic PROTOZOA/protists (3) + describe
- Entamoeba histolytica: amoebic dysentery. –> amoeba –> GI infection
GIARDIA LAMBLIA:
- giardiasis (backpacker’s disease/beaver fever)
- chronic diarrhea, often associated with drinking water in wilderness areas (beavers and muskrats are frequent carriers – source of contamination of streams/pees in stream)
CRYPTOSPORIDIUM PARVUM:
- acute diarrhea in healthy individuals –> self-limiting
- chronic diarrhea & major problem in immunocompromised individuals (AIDS, chemo), no reliable treatment
- Present in 90% sewage samples, 75% river waters and 28% of drinking waters –> prevalence is high + hard to ged rid of
G. lamblia and C. parvum can form ______A_____ that are resistant to WHAT
- C. parvum ____A_____ are NOT effectively removed by what?
- CYSTS! resistant to several disinfectants, including chlorine!
- C. parvum cysts are VERY small –> not effectively removed by filtration process in water plants
WATER-QUALITY CONTROL
- goal?
- is it possible to check for all pathogens? –> what to do instead?
- 2 indicators
- presence of the 2nd one, especially ________, indicates WHAT
- absence of both indicators ensures that the water quality is good?
- goal = make sure water is safe for drinking!
- Impossible to check for all pathogens –> bc most water-borne pathogens are associated with fecal material –> Test the water for organisms that are present in large numbers in feces – use these organisms as indicators of fecal pollution – if these organisms are present, there is a chance that the water may also contain pathogens.
1) COLIFORMS:
- facultative aerobic, Gram-negative, non spore-forming, rod-shaped bacteria that can ferment lactose with gas formation within 48 hours at 35°C –> not super specific
*ferment lactose –> MacConkey agar
- Includes a variety of bacteria not all of intestinal origin.
- indicates general contamination
2) FECAL COLIFORMS
- coliforms derived from the intestines of warm-blooded animals (can grow at 44.5°C, thermotolerant)
- ie E. coli
- indicates contamination from fecal matter
- presence of fecal coliforms, especially E. coli, indicate FECAL CONTAMINATION and that the water is unsafe for human consumption.
- absence of fecal coliforms/coliforms does NOT ensure good water quality (cysts are more resistant than fecal coliforms).
what are 2 ways to test for coliforms? explain
1) MEMBRANE FILTRATION
- test coliforms and fecal coliforms
- test large volume of water (100mL) –> pour sample in flask but has to pass through membrane filter –> put membrane filter on culture medium (probs smtg that can identify lactose fermentation) –> check growth of colony + color of colonies
- have to concentrate sample bc need to detect 1 bacteria/100 mL
- faster and easier than MPN
2) MOST PROBABLY NUMBER (MPB)
- test for coliforms: samples are added to lactose broth. If gas production is detected (change color (?)), test is positive = safe (?)
- Use statistical tables to estimate the MPN of coliforms in the original sample –> look at number of large wel; and # of small well –> where they interact = MPN number
- Presumptive tests, further tests needed for confirmation.
*can also use PCR to detect DNA –> but doesnt mean bacteria is alive
what are the 4 aims of water treatment?
- extent of treatment needed depends on what?
*death rates of typhoid fever in USA decreased after WHAT began?
- remove pathogens –> not trying to sterilize!
- improve clarity of water
- remove compounds that give bad smell or taste
- soften the water/adjust mineral quantity
*overall goal: make water potable - depends on the quality of the source of water
*after chlorination began
