Microbio of Water Flashcards
percent of the earth that is covered in water
71
how much water (%) do the oceans hold
96.5
light will penetrate to ta max depth of ____ know as the
300m, photic zone
halotolerant
high salinity
75% of the ocean is deeper than ____
1000m
pressure at 11km below surface
1100 atmospheres
constant temperature below 100m
2-3 degrees C
oligotrophic
relatively poor in plant nutrients , poor primary productivity, lack of nutrients, P, N
the open ocean is ____
oligotrophic , temperatures are more constant than areas closer to shore
in some regions, wind and ocean currents cause an upwelling of water form _____
ocean floor that brings nutrients to the surface
bulk of primary productivity comes from
prochlorophytes (tiny phototrophs phylogenetically related to the cyanobactreria
general adaptations seen in pelagic (open ocean) microorganisms
- reduced size
- high affinity transport systems
Trichodesmium
-Filamentaous cyanobacteria
-contains phycobilins
nitrogen fixing
Trichodesmium blooms
sea sawdust/ straw
scene on ferries
primary producers in coastal waters
algae and cyanobacteria
nutrient content in coastal waters
Eutrophic - high nutrients bc of influx from rivers ( excess nitrogen from agricultural runoff)
red tides
dinoflagellates, caused by eutrophication
between 300 and 1000 m what happens
chemoheterotrophs degrade organic matter that falls from the photic zones
below 1000 m
organic carbon is very scarce (oligotrophic), no light
- ones that survive have to be : psychophilic, basophilic, barotolerant
Tube worms
symbiosis with sulfur oxidizing chemoautotrophs. tube worms trap and transport nutrients to bacterial symbionts ( hydrothermal vents )
oligotrophic lakes
N and P are limiting, so primary production is low and therefore availability of organic matter( dead primary producers) is low
O2 remains high
oxygen saturated
lake remains aerobic even at deep depths and organic matter is degraded completely
Eutrophic lake ( nutrient rich)
algae blooms, availability of organic matter (dead primary producers) is high
- rapid growth of chemoheterotrophs, rapid depletion of dissolved oxygen ( they are using it )
- low O2
-anaerobic zones are created
poor light penetration
health risk: pathogens, blooms, toxins
bottom sediment of Eutrophic lake
bottom sediments are anaerobic and plenty of dead primary producers (organic matter) so denitrifies, methanogens and sulphate reducers thrive!
- can give the water a bad odor and lack of O2 and presence of H2S may kill fish and other aerobic organisms
Anaerobic zones may develop as a result from
summer stratification ( lakes become thermally stratified- (arranged or classified into different groups- ex, epilimnion, thermocline, hypolimnion
Epilimnion
the upper warmer layer in a stratified lake
- less dense and aerobic
Hypolimnion
the colder bottom layer in a stratified lake
Thermocline
sone of rapid temperature change in between the epilimnion and hypolimnion layers of a stratified lake
when does mixing of lake s occur
spring and winter
rivers ensure that organic matter is ___
degraded effectively ( no fermentation , no H2S production )
Biochemical oxygen demand (BOD)
used as a measure of the extent of pollution by organic matter
in areas of high pollution BOD is
high
- water tend to be anaerobic
- sewage is rich in organic matter
- microorganisms oxidize organic matter (pollution) using dissolved oxygen ( so biochemical oxygen demand is an indicator of the amount of pollution )
biofilms
microbial cells embedded inside an extracellular matrix
- mixed species
- cells inside the biofilm are more resistant to stresses than planktonic (free living cells0
Water born pathogens grow where?
most grow in intestine and than passed through water
Shigella
bacterial dysentery (infection in the intestine resulting in severe diharria)
Bacterial water borne pathogens (4)
Salmonella typhi and spp
Cholerae
Shigella
Campylobacter
Water born pathogenic protozoa
Entamoeba histolytica
Gairdia lambia
Cryptospordium parvum
Giardia lambia
G. lambia
backpackers disease/beaver fever
- beavers and muskrats are common carrier
drink water - fever and chronic diharria
Crypt-o-sporidium par-vum
c. parvum
no reliable treatment
- present in 90% sewage samples, 75% river waters
diharria
-dangerous for immunocompromised individuals
both G. lamb and C.parvum form _____
cysts that are resisted tot a number of disinfectants, including chlorine
C. parvum are not removed by filtration in water plants why?
too small
Two indicators in water quality control
Coliform –> gram- neg, facultative aerobic, non-spore forming, ferment lactose with gas formation within 48 hours ( not all in intestinal orgin)
fecal coliforms- derived from the intestine ( can grown at 44, thermotolerant )
what temperature can fecal coliform grow at
44, thermotolerant
fecal coliforms in water indicate
unsafe to drink
the absence of fecal coliforms indicate
not that it is safe, bc cysts could still be present
Most probable number (MPN)
test for coliforms
- samples are added to lactose broth if gas produced = positive
use stats table to estimate MPN of coliform in original sample
preemptive test- more needed
membrane filtration
- Eosin-methylene blue medium is ______ and ______ for _______ bacteria
test large number of water (100ml )
- coliforms and fecal coliforms
- eosin-methylene blue medium is selective and differential for lactose- fermenting bacteria
Steps in water treatment
1) sedimentation
2) Flocculation treatment ( chemical coagulation )
3) Filtration
4) Disinfection
Flocculatin treatment (chemical coagulation)
a flocculating ( to cause the forming of small clumps) chemical is added -80% of bacteria, colour and particles are removed
filtration
through sand
- any remaining G. lamb cysts are removed
- 98-99% bacteria is removed
Disinfection
chlorination
- chlorine is very creative in water and forms strong oxidizing agents – kills remains microorganism and neutralizes most chemicals
residual chlorine
amount left in water to protect during distribution system
ozone
more effective than chlorine but very short half-life
quality control in Montreal
less than 10 coliforms/ 100ml
les than 1 fecal coliform/ 100ml
Wastewater sewage treatment plan - primary treatment
primary- produces primary sludge, reduces BOD to 25-40% and bacteria 25-75%, can be discharge into waterway or go through secondary treatment
secondary treatment
trickling filter - wastewater from primary treatment is sprayed over bed of rock - biofilms form , coating th surface and oxidize the organic matter present, reduces BOD
Activated sludge- air is blown through the liquid from primary treatment, slime forming bacteria grow and clump to form activated sludge that oxidize the organic matter than slugs removed
trickling filter
liquid sprayed over bed of rock, biofilms created, removed microorganism, BOD reduced
Activated sludge
air blown through, slime forming bacteria ground clump into activated sludge , than removed , reduced BOD and bacteria growth
what do they do with the sludge
subjected to anaerobic conditions and micro bacteria
CH4 produced can be used for energy
tertiary treatment
further reduces BOD bacteria and N and P concentrations
the final liquid effluent that comes may be suitable for drinking ? T/F
true
Septic tank
minimal treatment of sewage
- BOD reduced 60%
- effluent flows to leaching field ( still contains 10000 coliforms
