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88 Cards in this Set
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how do we generally subdivide aquatic microbiology?
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freshwater vs. marine types still variable - different microhabitats for microbes (surface vs. deep) |
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marine habitats intertidal zone |
area of seashore that is submerged at high tide and exposed to air during low tide harsh environment due to alternating moisture, heat, and oxgen exposure includes: neritic zone and pelagic zone |
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marine habitats intertidal zone neritic zone |
water above continental shelf sunlight reaches the bottom diversity of producers |
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marine habitats intertidal zones pelagic zone/oceanic zone |
deeper ocean with a larger water column |
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marine habitats neuston zone |
air-water inteface that extends less that a millimeter down contains highest concentration of microbes with lots of algae, protists, and bacteria floating on the surface or utilizing surface tension very high oxygen and light concentration |
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marine habitats photic zone |
a measurement of depth - goes down 100-200 meters receives light = phytoplankton are abundant oxygen levels decrease with depth |
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marine habitats disphotic/twilight zone |
receives faint or filtered sunlight = no photosynthesis is possible cold water at high pressure little microbial growth |
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marine habitats aphotic/midnight zone |
deep ocean with no light at all intense pressure and near freezing heterotrophic bacteria feed on org. matter that has fallen; lithotrophic bacteria feed on inorg. matter for energy lots of bioluminescence occurs |
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marine habitats benthic zone |
ocean floor and its sediment crushing pressure, almost no oxygen, temperature extremes (intense cold and geothermal vents) lots of archaebacteria |
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what distinguishes freshwater from marine habitats and what are the major types of freshwater habitats? |
freshwater habitats are defined by their relatively low salt concentrations - can accommodate microbes sensitive to high [salt] variety: - brackish estuaries: mix of fresh/salt water - nutrient rich vs. poor lakes & ponds - rivers & streams - wetlands: includes swamps, bogs, marshes |
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lakes & ponds how do we define the water column? |
water column defined by aeration, depth, nutrient composition, and temperature |
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lakes & ponds oligotrophic lakes |
- clear, blue water - deep, undisturbed lakes with dilute nutrient composition - not a lot of microbial growth |
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lakes & ponds oligotrophic lakes major layers |
- epilimnion: upper region - thermocline: thin layer transition zone - hypalimnion: lower region |
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lakes & ponds oligotrophic lakes epilimnion |
upper region - supports large # of oxygenic phototrophs (algae, cyanobacteria) - warm, well oxygenated and mixed |
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lakes & ponds oligotrophic lakes thermocline |
- thin layer between - steep temperature transition zone that changes with the seasons - cold beneath |
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lakes & ponds oligotrophic lakes hypalimnion |
- lower region - includes benthos (bottom) - anoxic, cold water - greater growth of anoxy. phototrophs, sulfur/sulfate bacteria, archae (alt e- used by lithotr.) |
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lakes & ponds eutrophic lakes |
- shallow, nutrient rich - more plant / fish / microbial growth - water = murky - nutrients added from age, detergents, fertilizers, and sewage (N, P, org. pollutants) |
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lakes & ponds eutrophic lakes algal blooms |
caused by extreme eutrophication - increased nutrients = growth of more algae - dying algae = heterotrophic bact. rapidly consuming & reproducing - excessive hetero. depletes oxy. levels crucial for respiration = lakes becomes either permanently or temporairly anoxic |
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rivers & streams |
- relatively shallow, nutrient rich, better oxygenation (from constant movement) - composition changes almost daily & more prone to widespread contamination - microbial growth high from organic matter present = argicultural run off, industrial waste, sewage |
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wetlands |
high levels of nutrient cycling: - transition between terrestrial/aquatic - helps protect inland/coastal from eutroph. - lots of plants/roots, agricult. run off, decomp. microbes: - highly productive - sulfate reducers, nitrogen fixers, methanogens, iron utilizers - largely anaerobic because of roots |
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aquatic microbe difficulties |
- communication - nutrient availability - osmotic stress |
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aquatic microbe difficulties nutrient availability |
sheer size of some bodies of water dilutes out many of the nutrients that are necessary for life
soutions: motility, scavenging enzymes |
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aquatic microbe difficulties communication |
being too dispersed can negatively impact communication between microbes solutions: biofilms onto substrates |
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aquatic microbe difficulties osmotic stress |
freshwater microbes may be exposed to hypo. environments while marine microbes may be exposed to hyper. conditions can cause lysis (=hypo.) or plasmolysis (=hyper.) |
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aquatic microbe difficulties osmotic stress hypotonic conditions |
adaptations: - cell walls of bacteria and fungi prevent osmotic lysis - protists and algae have contractile vacuoles (don't have cell walls) - transport ions out of the cell |
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aquatic microbe difficulties osmotic stress hypertonic conditions |
adaptations: - microbes can produce a thick sugar layer that surrounds the membrane called the glycocalyx (capsule, matrix) - limit flow of ions and water - gram neg. bact. have protective LPS layer in cell wall - some retain higher solute in cytosol |
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aquatic microbe food webs |
- can drastically alter chemistry of water around them - can harm or kill any form of aquatic life and humans - form base of all aquatic food webs - include: cyanobacteria and phytoplankton |
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aquatic microbe water quality |
- aquatic decomposers living planktonically or within sediment (benthic) break down all organic wastes/dead organisms - return nutrients back into the water - recyle N, C, S for new producers - excessive growth however = depletion of O2 *anoxic water = deadly to fish/plants |
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aquatic microbe animal diseases |
- Fibropspilloma-Associated: Turtle herpesvirus - Ichthyophthirius multifilis: protozoa causes fish ich - epidemics like red tide: algal bloom of Karenia brevis secrete neurotoxins that kill fish/marine mammals - coral bleaching: bacterial infection |
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aquatic microbe waterborne human pathogens |
- most often due to contamination of drinking water - causes: diarrhea, dysentary, severe fever (....meningitis, brain damage), liver inflammation/failure |
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aquatic microbe waterborne human pathogens E. coli - two strains |
enterotoxigenic E. coli: major cause of traveler's diarrhea enterohemorrhagic E.coli: causes hemorrhaging and kidney failure |
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aquatic microbe waterborne human pathogens Salmonella enteritidis |
- causes self-limiting watery diarrhea for most - enters water via sewage contamination or bird droppings |
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aquatic microbe waterborne human pathogens typhoid fever |
- Salmonella typhi - raw sewage contamination of drinking/bathing water ; can also spread via hands of infected individuals - causes: sustained fever (+104F), brain damage rash, organ failure |
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aquatic microbe waterborne human pathogens vibrio cholerae |
- causes: severe watery diarrhea and death w/in 1-2 days - cholera toxin opens up Cl- ion channels - spreads rapidly in countries with poor sanitation |
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aquatic microbe waterborne human pathogens Shigella & friends |
shigella dysenteriae: - similar to hemorrhagic E. coli cause they both cause fatal dysentary - shiga toxin kills large number of intestinal cells = bloody diarrhea and shock |
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aquatic microbe waterborne human pathogens Campylobacter jejuni |
- produces heavy diarrhea and some dysentary - problematic for young kids, elderly, immunocompromised - can spread beyond for these individuals |
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aquatic microbe waterborne human pathogens viruses |
often naked - envelopes are unstable for long periods in water |
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aquatic microbe waterborne human pathogens rotavirus |
- most common cause of diarrhea and vomiting in kids - spread by exposure to contaminated objects / via water - increased santiation does not help lower infection rates |
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aquatic microbe waterborne human pathogens hepatitis A vs. E |
- common causes: jaundice, acute liver inflammation, fever, vomiting, diarrhea - Hep A: spread by contact w/ contaminated item, and water, shellfish - Hep E: spread via fecal contamination in water |
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aquatic microbe waterborne human pathogens poliomyelitis |
- fecal contamination in water - majority of those affected: no symptoms or minor diarrhea - that 1%: virus goes to central nervous sys. and causes meningitis, seizures, paralysis, and death - prevented with an oral vaccine - almost eradicated |
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aquatic microbe waterborne human pathogens norovirus |
- mainly transmitted via food or fomites - extremely contagious - causes vomiting / diarrhea - common in schools / daycares / cruises / restaurants |
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aquatic microbe waterborne human pathogens Giardia lamblia |
- caused by flagellated protozoa - contaminated water contains animal excreted cysts (can surve months) - causes: diarrhea, weight loss, lactose intolerance |
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aquatic microbe waterborne human pathogens amoebic dysentery |
- caused by Entamoeba histolytica (tissue-destruction) cysts - from sewage contaminated drinking water - trophozoite growth in intestine produces intense cramping and bloody diarrhea |
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aquatic microbe waterborne human pathogens Cryptosporidium |
- commonly infects HIV patients (immunocompromised) - fecal contamination of cysts in drinking or swimming water (can resist chlorine) - causes: severe weight loss, diarrhea, respiratory illness |
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aquatic microbe waterborne human pathogens Schistosoma |
- parasitic flatworm that spreads via freshwater snails - can penetrate skin = children commonly affected - causes: diarrhea, intestinal damage, liver/kidney development, bladder cancer, malnutrition, and negatively impact development |
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aquatic microbe waterborne human pathogens Ascaris lumbricoide |
- parasitic roundworm most often spread through sewage contamination of drinking/crop water - can fill up intestines once infected - causes: severe abdominal discomfort, malnutrition, lower IQ, larvae can spread to lungs and cause pneumonia |
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aquatic microbe waterborne human pathogens four forms of prevention |
- boiling: very effective; costly for 3rd world - disinfection: heavy metals, halogens - filtration: charcoal, sand, ceramic, membrane - UV light: destroys DNA in pathogens, expensive |
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aquatic microbe beneficial uses |
bioremediation and wastewater treatment: natural aquatic decomp. amazing at degrading organic and chemical wastes algae biofuels: some species make long chain hydrocarbons that can be used as fuel without impacting climate; too expensive for widespread use |
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aeromicrobiology |
study of microbes that are found suspended in the air - called bioaerosols - can be found on water droplet nuclei, attached to soil particles, or floating on dust |
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aeromicrobes ability to travel |
depends on size of microbe, what it's attached to, and the humidity of the air - smaller the aerosol, longer it can remain suspended - more humidity = aerosols fall faster to ground |
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aeromicrobes difficulties of air travel |
- air is not hospitable: dry, cold, UV radiation - must have mechanisms for survival: endospores, fungal spores, capsules, cell walls |
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aeromicrobes water cycle |
airborne species high in the atmosphere make proteins that nucleate ice formation there's good evidence that these microbes can nucleate the formation of clouds in upper atmosphere and help control the water cycle |
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aeromicrobes airborne transmission |
- launching of bioaerosols from source: coughing, kicking up dirt, dusting - transport via air movement: dispersal from point A to point B via wind, air conditioning - deposition onto a surface or in a person: via gravity, diffusion, rain |
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aeromicrobes plant disease |
fungal diseases: dissemination of spores transmitted by wind ex: plant rust disease downy mildew leaf spot disease blights |
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aeromicrobes human-human disease |
spread person-person via inhalation of contaminated aerosols (depends on size of droplet nuclei) ex: rhinovirus, measles, tuberculosis, whooping cough, diphtheria |
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aeromicrobes soil-human disease |
some human pathogens spread via inhalation of contaminated soils or dust - abundant endospores in the soil like botulism and anthrax (rare naturally, need lots of spores) - Hantavirus acquired when dust containing mouse feces/urine is disturbed and inhaled |
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aeromicrobes air-human disease |
poor ventilation and high humidity levels in buildings can lead to major growth of mold / mildew / bacteria constant inhalation can lead to allergy/asthma, pneumonia, & sick building syndrome (Legionnaires in Philly) |
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aeromicrobes three stragies for prevention |
- face masks: against personal aerosols - HEPA filters: can remove bacteria / mold spores / some viruses - UV light: destroys mold spores, located in some AC systems |
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biowarfare |
intentional or threatened use of microbes or toxins from microbes to produce death, disease in humans, plants, animals - can also be used to target food/water supplies - goal is to induce mass hysteria (bioterrorism) |
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biowarfare benefits to weaponization |
- cheap mass production - difficult to detect / easy to hide - designed to effectively spread - ease of genetic manipulation - minimal technical experience required |
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biowarfare early history first use of bioterrorism - 1346 |
Caffa (Crimea) 1346 - bioweapons used before people knew how microbes caused disease - Mongols were mass killed by bubonic plague outbreak while attacking Italian merchants - during retreat, launched dead soldiers into city and plague broke out in the population, causing them to flee city |
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biowarefare early history 1495 |
spanish put blood of leprosy patients into wine they sold to french not effective at all because leprosy isn't spread via ingestion - takes ages to develop symptoms |
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biowarfare early history 1763 |
british settlers give a bunch of smallpox infected blankets to the native americans europeans exposed to smallpox as children = "vaccinated" while native americans susceptible to infection = 500,000 died |
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biowarfare modern history World War I |
germans tried to infect livestock with glanders and anthrax spores to cause mass die-offs in farms and the army didn't work for subsequent battles, but high rates of diseases in russia prevalent afterward |
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biowarfare modern history World War II |
Japanese tested >25 agents on prisoners and civilians in infamous Unit 731 = killed thousands used weapons on Manchuria China - cholera/typhoid in wells, plague fleas dropped into major cities, anthrax dusting? - planned for US attack |
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biowarfare modern history Cold War |
both USA and Soviets amassed literal tons of weaponized plague, smallpox, anthrax, many more both documented tests on their own populations |
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biowarfare traits of a good bioweapon |
- cheap & stable - easy to produce & disseminate to enemy - high infectivity: low amount needed to cause reaction - high virulence: causes quick disease in many individuals w/ high mortality rate - no vaccines/treatments |
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biowarfare offensive vs. defensive |
offensive: intent to kill or incapacitate human targets, livestock, or crops - easier to target bodies of water/plots of land = harder to defend - goal may be to cause mass hysteria/panic safety of own army/population - vaccines/prophyletic drugs; expert handling; regulated production
defensive: Research and development of countermeasures Biodetectors/widespread surveillance |
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biowarfare offensive four considerations |
mode of dissemination: - create entirely new agent: DNA tech allows new genome design - genetic alteration of agent: increase antibiotic resistance / evade immunities or detection - increase released stability: longer persistance = greater chance of infection - size of aerosol: smaller = longer in air (anthrax) |
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biowarfare defensive |
goal is to prevent, track, contain bio attacks concerned with: - detection of infections agents in the air or water: biodetectors like PANTHER - research and development: vaccines, new treatments, containment - widespread surveillance: clinicians and vets report unique cases |
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biotechnology environmental definition |
using biological agents and chemical, physical, and engineering processes to maintain, protect, and restore the environment includes: - bioremediation - composting - treatment and disposal of solid waste - treatment of wastewater |
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biotechnology landfills goals and benefits |
- oldest and most common - goal's to fill solid waste compactly in small area that does not destroy surrounding soil/water - fewer people needed, little mechanization, usually safer |
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biotechnology landfills bioreactors |
the mechanization of landfills for a purpose
- add moisture and allow microbes to decompose waste - larger volumes of waste could be treated and some economically beneficial products made like methane (can be used to power entire landfill) |
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biotechnology landfills design |
- bottom consists of impenetrable (double plastic) liner with drainage layer of sand and gravel on top to prevent ground water contamination underneath - pipes w/in drainage layer to collect water and percolate through refuse - refuse placed on top of liner/drainage and embedded with horizontal and vertical pipes that collect CO2 and CH4 gases - final capplaced to limit water infiltration and encourage decomposition and gas collection |
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biotechnology landfills leachate |
contaminated waste water collected by piping in drainage layer that is collected in tanks and processed
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biotechnology landfills five phases |
- adjustment period - transition phase - acidogenesis period - methanogenesis period - maturation period |
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biotechnology landfills five phases adjustment period |
1st step - aerobic bacteria utilize trapped oxygen and decompose most carbons (CO2 + H2O) - moisture will begin collecting - continues until all the oxygen is used up |
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biotechnology landfills five phases transition phase |
2nd step
- anaerobic conditions begin to form - causes transition to fermentation and the production of organic acids |
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biotechnology landfills five phases acidogenesis period |
3rd step - acidogeneic bacteria ferment organic wastes, create high amounts organic acids - pH drops significantly, heavy metals mobilized - water added to promote growth of anaerobes - leachate must be monitored |
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biotechnology landfills five phases methanogenesis period |
4th step - alt. e- acceptors become limiting - fermentation of organic acids increased by bacteria = methanogens (products are methane and CO2) - pH moves towards neutrality - peak methane gas production |
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biotechnology landfills five phases maturation period |
5th step
- available nutrient levels and gas levels drop - continued slow decomp. will occur for years - organics turn into humus like material - decomp. can be sped up by added O2 |
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biotechnology landfills biodegradation of synthetic solids |
- take significantly longer than organic solids - can stay in landfills for centuries - difficult to balance creation of materials that last vs. environmental concerns |
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biotechnology biodeterioration |
utilizing newly developed materials that biodegrade more quickly through natural processes - biodegradable plastics / packing peanuts |
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biotechnology biofilms |
- major form of biodeterioration - form when proteins are deposited onto a substrate; bacteria/yeast begin colonization - attached org. will secrete matrix of polysacc. to form stronger microbe-microbe interactions - community will form as biochemical collaboration between species - growth and maturation = more difficult to remove |
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biotechnology biofilms biodeterioriation |
- cooling tower / drinking water facilities: can destroy imporant mechanical parts - medical implants: catheters, heart valves, contacts; can cause infection/weaken material - pipes: household, oil, municpal causing corrosion or blockages - ship hulls: weaken structure and create greater drag = high fiel costs |
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biotechnology biodeterioration major forms |
- biochemical - mechanical damage/physical disruption - soiling / fouling |
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biotechnology biodeterioration major forms biochemical |
assimilation: microbe uses substrate as a carbon source - eats away at it dissimilation: microbe secretes acid or enzymes during metabolism - substrate destruction is indirect by-product |
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biotechnology biodeterioration major forms soiling vs fouling |
soiling: simple presence of microbial growth or their by-products on an object makes it undesirable but functional ex: shower curtains, moldy water bottle fouling: microbial presence doesn't damage object but makes it toxic to other living things or impairs its performance making it non-functional ex: fungal spores releasing toxins into "bad" food |