273907
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Flashcards by ruby.white94, updated more than 1 year ago
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Created by ruby.white94
almost 11 years ago
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| Question | Answer |
| Oligotrophic | Few nutrients |
| Allochthonous | From environments other than where it has ended up |
| autochthonous | Native to this habitat |
| What are aquifers? | Water trapped under soil and above solid rock |
| What are some features of aquifers? | Very oligotrophic usually very pure 1/3 NZ ground water high in nitrate |
| Why does river nutrients vary? | Can be oligotrophic but varies Influx of tress,roots, leaves washed into river |
| Why are rivers so well oxygenated? | Moving water |
| What is a microbial feature that helps them survive in rivers? | Stalk production |
| what percentage of rivers are unsafe for swimming? | 52% |
| When are lakes stratified? | Summer and spring |
| What is the thermocline | The point in a lake where the temp drops dramatically Also point where to epilimnion and hypolimnion meet |
| What occurs in the mud sediment of a lake? | Methanogenesis, sulphate fermentation, anaerobic fermentation |
| What is produced in the mud sediment? | H2S, CH4 |
| What are the oxygen, H2S and temp like in the epilimnion, thermocline and hypolimnion? | O2 in E is high (10mg/l) in H is low below 8mg/l in thermocline between the two H2S is up to 12 in H but not in E or thermocline Temp 20ish in E, 10-4 in thermocline after that 4 or below |
| What is the community in the epilimnion? | Photosynthetic aerobes, phoic zone 6CO2 + 6H2O = C6H12O6 +6O2 |
| What is the second from surface community in a lake | Aaerobe and faculatative aerobes, oxic zone C6H12O6 + 6O2 =6CO2 + 6H2O |
| What are the four guilds of community three? | Guild 1 = denitrifying bacteria and ferric iron-reducing bacteria Guild 2 = sulfate reducing bacteria and sulfur reducing bacteria Guild 3 = fermentative bacteria Guild 4 = methanogenesis and acetogens |
| Denitrifying bacteria and ferric iron reducing bacteria | NO3- -> N2 Fe3+ --> Fe2+ |
| Sulfate and sulphur reducing bacteria | SO42- -> H2S S --> H2S |
| Methanogenesis and acetogens? | CO2 --> CH4 CO2 --> acetate |
| What are the gradients in a lake? | Light is high at top low at bottom energy yeild gets lower as you go deeper H2S gets lower as you go higher |
| Liebigs law of minimum | States that the total biomass of an organism is dictated by the nutrient present in the lowest conc relative to the organisms requirements |
| Shelfords law of tolerance | States that there are limits to environmental factors that below or above which a microbe can not grow regardless of the nutrients |
| Eutrophification | Increase in nutrients usually C,N and P. Sewage leakage etc |
| What doe eutrophification lead to? | An increase in oxygen decomposers and then a decrease in oxygen as it all gets used up Environment becomes anoxic Accumulation of toxic products by anaerobes |
| List the 6 adaptations microbes have to aquatic environments | 1. small cells 2. Sheathed bacteria 3. pigament production 4. Motility 5. Magnetotatic bacteria 6. Utilisation of nutrients in low conc |
| Two types of motility handy in an aquatic environment | Flagella Gas vacuoles |
| The advantage of magnetotactic bacteria | Have magnetosomes, membranous vesicles with FeO4 and iron sulphate gregiate helps overcome thermal forces and orientate the cell |
| High affintiy enzymes | Help uptake in oligotrophic environment |
| Halotolerant | Can tolerate changes in salt content |
| Halophilic | NaCl must be 2.5-4% Need high Na content to maintain high K content need for enzymes to work |
| How many atms of pressure increases every 10m of depth? | 1 |
| Barotolerant | Can handle change in pressure up to 4000m deep |
| Barophilic | Only live deeper than 4000m Enzymes only function at this pressure |
| Extremepiezophile | like about 800atm pressure |
| Warm vent | 6-23 degrees |
| Black smokers | 350 degrees |
| what is the trophosome sponge tissue high in? | Sulphur granules prokaryotic cells 10^9 per g/tissue |
| What goes in the bronchial plume and why is the plume red? | CO2 and O2 from seawater H2S from hydrothermal vents Red because of haemoglobin |
| How does H2S normally harm the tube worm? | It blocks O2 sites on the haemoglobin posions cytochrome c |
| How has the tube worm gotton around being posioned by H2S? | Modified haemoglobin with capacity for O2 and H2S binding haemoglobin Modified cytochrome c |
| What are the benefits for both the tube worm and the bacteria? | Bacteria are chemolithotrophic and get H2S Supplies host cells with organic molecules |
| Photobacterium are.. | Chemolithotrophic |
| What is the advantage to fish of having bioluminescent bacteria? | Attracts prey to fish |
| What do flashlight fish have to accomadate luminescent bacteria? | An organ wit a membrane that can open and close revealing or concealing light |
| What enzyme and what substrates are needed for light emitting reaction? | Enzyme luciferase long chain aldehyde compound (RCHO), oxygen and flavun mononucleotide (FMNH2) |
| What is the overall reaction for light emitting reaction? | RCHO + FMNH2 + O2 ----> FMN + RCOOH + H2O and light! Luciferase ATP --> ADP |
| What are shipworms | Mollusks, Teredo navalis |
| What do shipworms do? | Get into and destroy wood, they have mutualistic bacteria to destroy cellulose |
| Teredinibacter | Obligate marine bacteria that degrade celluose, found in shipworms Also fix nitrogen need nitrogenase and cellulase |
| What are algal blooms | Increase in nutrients that leads to algal bloom, which can make harmful toxins |
| What did the saxitoxin of the NZ alexandrium minutum do? | Blocks sodium channels enabling nerve impulses and killing animals Economic loss |
| Within 200m of water depth what is the temp like in the sea? | Greatly variable depending on where you are |
| What is the temperature range for most deep water? | 5 to -1.5 degrees |
| What is the freezing point of seawater? | -2 due to salt |
| What is the pH of the sea | 7.5 |
| Why did romans cover there aqueducts? | To stop algal growth (no UV) To keep it cool to stop leaves etc getting in |
| What lead to the start of water purification? | John Snow linking cholera to water supply |
| What are sources of potable water? | Ground water, aquifers, springs Surface water lakes, rivers and reservoirs Desalination of the sea |
| Catchment area | Area of land around a water source |
| Why is it so important for catchment area to be clean? | Determines the quality of water even after treament |
| What are some examples of natural pollution? | Minerals and salts, animal and plant waste, dissolved gases, run off from bogs and slit, natural radioactivity and heavy metals |
| Human pollution examples | Thermal, pathogenic microbes, organic matter, toxic compounds, eutrophification, detergents and radioactivity |
| What are the requirements for a clean catchment area? | Don't want agriculture on this land low amount of N and P, no landfills, industry and limited human access |
| Sediementation and screening | All solids settle and water is taken from the middle of the middle |
| Aeration | Removes dissolved gases |
| chemical flocculation | Aluminium potassium sulfate causes larger aggregates and air pressure causes flotation |
| Filtration | Rapid or slow sand filter should remove protozoan cysts Or membrane filter 2-5um big should also remove cysts |
| Chlorination | CL2 +H2O ---> Cl- H+ and HOCl HOCL is a strong oxidiser kills bacteria |
| residual concentration | Concentration that must be present at the furthest point from the treatment plant Cl - 0.2mg/l F - 0.85mg/l |
| UV treatment | 245nm Disrupts DNA and RNA thin stream flows past bulbs |
| Max values of E.coli and oocysts in water | E.coli <1/100ml oocysts <1/100L |
| BOD | Biological oxygen demand Measures the demand for oxygen by bacteria during degradation of organic matter and indicate conc of organic compounds in water |
| What is the con of testing for BOD | Tends to underestimate |
| COD | Chemical oxygen demand Potassium dichromate oxidises organic compouns to CO2 and H2O |
| Advantages and disadvantages of COD | Advantage is - rapid 3hrs Disadvantage can't distinguish between biodegradable portion and nonbiodegradable Overestimates but regular testing shows trends |
| Why does BOD tend to underestimate? | It doesn't measure all biodegradble portion |
| How is measuring BOD carried out? | Sample put in dark at 20 degrees and measured after 5 days |
| Why do we use a bacterial indicator instead of just testing for pathogens? | Wide variety of species and genra, have to do many cultures etc, takes too long, could be present in very few numbers but enough to cause disease |
| What is an ideal organism? | Bacterial inhibitor of the large intestine Non pathogen easy to identify present in large numbers survives long in water but doesn't reproduce |
| What is the best indicator organism? | A coliform, we use E.coli because it isn' found in soil |
| features of E.coli | Gram -ve rod Lactose fermentor with gas within 48hrs at 35 degrees |
| ONPG test | Coliform produces p galactosidase beta which acts on ONPG and turns it yellow |
| MUG test | E.coli produces beta-glucuronidase which acts on MUG and turns it fluroscent blue |
| What is the colihert test? | A commerical test add reagent to sample and incubate for 24hrs read it. |
| Membrane filtration test | Trap microbes of filter and put in on a slective and differential agar |
| Disadvantages of using a indicator bacteria | Bacteriophage, doesn't detect algae, E.coli might rapidly die off in some waters, viable but non culturable E.coli gives false negatives, clusting could give false negatives and positives |
| Rhizophere | The zone of root influence, extends 5mm from root |
| Rhizoplane | Root surface |
| Root colinization | bacteria grow as microcolonies over 5% of the root |
| Populations around the root are... | Usually 20-100 times more than in the surrounding soil |
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