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Microbes exam 4 pt 1

Terms in this set (134)

Where you find microbes in the environment is dependent, almost solely, on what?
Metabolism and how the microbe gets nutrients.
What does the term "microbial dark matter" mean?
Most microbes have never been cultured... we have not been able to do it.
What is anoxygenic photosynthesis?
Uses energy from sunlight to derive its carbon from CO2 ... coupled to oxidation of
elemental So or H2S (anaerobic conditions). Oxygen is not a product of this process.... sulfur has to be in sulfate form
What is chemosynthesis? What are chemoautotrophic microbes?
When certain microbes use energy derived from oxidation of inorganic chemicals, such as sulfur released from deep hydrothermal vents, to produce their carbon (no sunlight). Microbes that obtain energy through chemosynthesis rather than photosynthesis are chemoautotrophic.
What are photoautotrophic microbes?
Microbes that obtain energy through photosynthesis that get their carbon through CO2.
What is eutrophication?
Excessive richness of nutrients in a lake or other body of water, frequently due to runoff from the land, which causes a dense growth of plant life and death of animal life from lack of oxygen.
What is abiogenesis?
The original evolution of life or living organisms from inorganic or inanimate substances... the origin of life
What are the three main theories of abiogenesis?
1. Meteor or asteroid carrying the essential materials for life hit Earth.
2. RNA World: earlier life forms may have used RNA alone for the storage of genetic material.
3. Metabolism first: the compound methanethiol (a precursor to acetyl-CoA) found near thermal vents is the possible starting material
What are the elements required for life and what complex molecules do they make?
CHNOPS (Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorous, Sulphur), which makes amino acids, nucleic acids, carbohydrates, lipids.
What kind of photosynthesis would have been compatible with Earth's primordial environment?
Since Earth's primordial atmosphere would have been anoxic (O-free), anoxygenic photosynthesis.
Which came first, anoxygenic or oxygenic photosynthesis?
Anoxygenic.
What are deep sea thermal vents and how do scientists study them?
When water seeps into cracks in the deep ocean floor, it encounters magma, becomes superheated, and is forced back out in plumes. These plumes contain minerals, elements, and heavy metals. One of the popular theories of creation of life of Earth is through these deep sea vents, and scientists study them to study the origins of life.
What are thermophiles and hyperthermophiles?
A bacterium or other microorganism that grows best at higher than normal temperatures. Organisms that grow at extremely hot temperatures are hyperthermophiles.
What are some of the astonishing features associated with deep sea thermal vents? What is the origin of these features?
Deep sea vents have an unusually high biomass and fast growth rate of microorganisms around the vents. This is due to the chemical energy surrounding the area.
When do black plumes emit from thermal vents?
When there are extremely high temperatures. (>400 degrees C)
When do white plumes emit from thermal vents?
When there are lower temperatures. (100-300 degrees C)
What are microbial mats around deep thermal vents? What are they made of and why are they important?
The are made up of chemosynthetic bacteria (Archaea) that are essential for life around these vents. All of the life around this area is dependent of chemosynthetic bacteria.
What are Extracellular Polymeric Substances?
Potential structuring agents in the formation of stromatolites; secreted by cyanobacteria; protect from UV radiation, controls microenvironment, and traps sediment and minerals.
What are stromatolites?
Fossilized microbial mats made of blue-green algae that provide a record of ancient life.
What kind of life could be living below the ocean floor?
A diversity of microbes, all 3 domains of life... Archaea predominant. These microbes would have a very slow metabolic rate, dependent on sulfate or nitrate reduction, or methanogenesis
What are the two sources of Oxygen in the Oxygen cycle?
50% plants + 50% cyanobacteria
What are the four main roles of environmental microbes?
1. Recycle nutrients
2. Refresh our environment
3. Clean our waste
4. Are the link to life as we know it
Why is it so important that we recycle nutrients on Earth?
Our planet can be viewed as an organism with a finite amount of resources, that must be recycled for it to be sustained.
What is aerobic carbon cycling?
in soil: decomposition of organic matter by bacteria & fungi and subsequent release of CO2.
in water: phytoplankton & zooplankton use CO2 in photosynthesis
What is anaerobic carbon cycling?
in muddy/waterlogged soil: decomposition by Archaea
species to produce methane (CH4) ... further degraded into CO2 and H2O by aerobic microbes
What microorganism stands at the base of the oceanic food web?
Phytoplankton. They are the primary producers of biomass using light and CO2 conversion. Their importance as a food source for the pelagos (food web) and as a potential sink of atmospheric carbon is vital.
What is humus in composting?
nutrient rich fertilizer additive for plants
obligate anaerobes
all known organisms that carry out anoxygenic photosynthesis
Earth's main sulfur sink is:
Sulfate in the ocean
Explain the nitrogen cycle and the different ways that nitrogen gets processed in the environment.
Nitrogen Cycle is a biogeochemical process through which nitrogen is converted into many forms, consecutively passing from the atmosphere to the soil to organism and back into the atmosphere. It involves several processes such as: a. decomposition, b. anaerobic and aerobic fixation (microorganisms take nitrogen from the air and soil and turn it into other compounds, like ammonium, that can be used), c. nitrification (bacteria makes nitrates), and d. denitrification (nitrogen gas is produced from nitrites and nitrates.)
What is Rhizobium? Why is it important?
A bacteria that secretes a protein that can bind to roots on plants and creates a fixed form of Nitrogen that the plants can use. This is useful to the plants because there is a limited amount of Nitrogen in the soil.
What is Azotobacter?
A soil bacterium that is that has the highest respiration rate of any organism. It removes oxygen very quickly so that nitrogenase can work in aerobic environments.
What is nitrogenase?
It is the enzyme that bacteria use to catalyze the reaction of Nitrogen from it's diatomic gaseous state (N2) to ammonia (NH3). It is coded for by rhizobium.
What are ways that soil bacteria enhance Phosphorous uptake in the environment and why is this important?
There is a limited amount of Phosphorous in the environment, so it is helpful for soil bacteria to help plants with uptake. They do this through: 1. direct metabolic and physiological processes and 2. extension and stimulation of root growth
Why do waterborne microbes trap phosphorous?
To keep the phosphorous from sedimenting, which would make it unavailable.
Has phosphorous in lake Champlain decreased or increased in the past 25 years?
Decreased, but not significantly.
How will the pH of the ocean change by 2100?
It will become more acidic, dropping .2-.4 units.
What climate change effects have we already seen in the ocean and soil in regards to the elemental cycles?
changes in calcification, increased nitrogen fixation, reduced nitrification
What is biodegradation?
The breaking down of organic matter into inorganic matter by microorganisms.
What is bioremediation?
The breaking down of organic matter into inorganic matter by microorganisms, initiated by humans and faster than biodegradation. This could be a possible energy source.
What are the three primary "ingredients" of bioremediation?
1. Presence of a contaminant
2. Presence of microorganisms that are capable of degrading the contaminant
3. environmental factors:, nutrient availability, moisture content, pH, temperature of the soil matrix, inorganic nutrients such as nitrogen & phosphorus
What is a septic tank?
A tank in which waste from a household can be deposited and processed through bioremediation before being filtered into a leach field. Organic matter gets digested by anaerobes, which leaves behind sludge and gas. Accelerator products can be added. Sludge in septic tanks needs to be periodically cleaned.
What is a leach field?
After waste gets processed through a septic tank, it gets filtered into a leach field, where aerobic and anaerobic bacteria will digest the rest of the waste. Leach fields are constantly "dying"
What happens if there is not enough O2 available in a leach field?
The anaerobic bacteria will start to work more than the aerobic bacteria, and a biomat will form. This is a thick black mat that is very expensive to get rid of.
Sewage treatment is a 3-step process. What is the first step?
Separation of solids and liquids; solids get sent to an anaerobic tank.
Sewage treatment is a 3-step process. What is the second step?
Liquids get treated with oxygen and aerobic bacteria, which forms an activated sludge. This sludge gets partially reprocessed, while the rest gets sent to an anaerobic tank. Trickling filters or moving bed bioreactors (MBBR), which rely on formation of biofilms, may also be used to process this sludge.
Sewage treatment is a 3-step process. What is the third step?
Secondary fluids get treated so that any harmful chemicals get filtered out and chlorine, UV light, or ozone may be used to filter out any pathogens. In an anaerobic tank, remaining sludge will be process for 10-20 days, half of which will turn into biogas.
What are the final products of sewage treatment?
Clean water, methane (possible source of energy), fertilizer, and CO2.
Why is biomethane a great renewable natural gas?
It can be sourced from manure, food, wastewater sludge, and yard waste. It has near 0 net carbon emissions, it is sustainable, and it is interchangeable with natural gas.
Describe the 4 main steps of water treatment?
1. Sedimentation: water from lakes, storage tanks, wells, springs, etc. that has already been filtered of large particles gets a flocculating agent (alum) is
added. Small particulates & microbes aggregate into jelly-like mass (floc) and precipitate.
2. Filtration: microbes get physically removed through sand, membranes, or charcoal.
3. Chlorination: chlorine gas kills bacteria
4. Softening and fluoridation
Describe the BP Deepwater Horizon Oil Spill.
An explosion caused a pipe of collapse, spilling 200 million gallons of oil, along with methane... chemical dispersants used both at the surface and at the wellhead. Annually, millions of gallons of oil seep up from the ocean floor. Bacteria surrounding these seeps have evolved to use hydrocarbons as energy and carbon sources.
Describe the Exxon Valdez oil spill and what methods of cleaning were used.
11 million gallons of heavy crude oil was spilled. Nitrogen-containing fertilizers were injected into the area to stimulate growth of indigenous oil-eating bacteria. This was the first large-scale biostimulation experiment.
Why does the oil spilt in the Exxon Valdez spill persist so strongly today?
Physical weathering and biodegradation should naturally remove oil, but this area lacks the natural resources to do that. There are also lower dissolved oxygen levels in the area.
Why is the mass production of plastic so terrible for the environment?
Mass-produced plastics are derived from fossil fuels. Ecological disasters that release plastic into the ocean harms marine life.
How can microbes be used to clean plastic in the environment?
Microbes, identified by screening natural microbial communities at plastic recycling sites or in gut flora of
certain insect larvae, can metabolize certain plastics. Microbes/microbial enzymes are emerging as promising candidates for bioremediation of environmental plastics
Wat is bioleaching?
Using microbes, rather than smelting, to release metals from low-grade areas or electronic waste.
How are Microbial Fuel Cells (MFC) used to create electricity?
Unprocessed urine flows through MFCs ... bacteria metabolize it and generate electricity.
Processed fluid can be purified to yield nitrogen & phosphorus ... used in fertilizers and water.
How can Fungal Mycelium be used to create renewable materials?
Fungal Mycelium can be introduced to corn stalk and other agricultural waste to create compostable & non-toxic materials like: foam, insulation, wood textile substitutes, etc.
What is the hygiene hypothesis?
Childhood exposure to germs and certain infections helps the immune system develop. Modern day smaller families and increased hygiene has caused an increase in allergies. Use of antimicrobials before the age of two can increase risk of developing allergies.
What is the 'old friends mechanism'?
Purposeful exposure to indoor and outdoor microbes during birth and infancy is crucial to proper immune development.
What are Th1 and Th2 cells and what importance do they play in immune development?
T cells determine the type of immune response you will have to different pathogens. Th1 = intracellular pathogens and Th2 = extracellular pathogens... interplay between activation of TH1 and TH2 cells is
important in allergy development. For example, exposure to a farm environment promotes Th1 development.
What importance do cytokines play on immune development?
Proteins, such as interferon, interleukin, and growth factors, that are secreted by certain immune system cells and have an effect on other cells
Describe the "Wild Life of Our Homes" Project taking place in the Rob Dunn Lab
Looks at the way built environments (BE) are complex ecosystems dependent on their inhabitants, and interactions between those inhabitants and the building materials.
Indoor ecology includes: home, office, hospitals, etc.
What kind of bacteria is found on common household items?
Skin bacteria, mouth bacteria on pillowcases, fecal bacteria on toilet seats
How are households with pets different in terms of biodiversity compared to homes without pets?
Homes with dogs have greater biodiversity and a decreased risk of developing allergenic diseases.
What is the "dirtiest" room in the house and where is the most bacteria found in that room?
The kitchen. Vast biodiversity around stove, floor, fridge, and SPONGE, which carries coliforms (rod-shaped bacteria like E. coli). Sink itself had least biodiversity.
How do you clean a household sponge?
Microwave for 20 seconds.
Does the "5 second rule" actually impact how much bacteria gets transferred to food?
No, most bacteria were transferred to foods near the initiation of contact and then quickly reached a point that showed no increase in transfer
Do feather pillows or synthetic pillows have higher or lower biodiversity? Which is more likely to result in asthma?
Synthetic pillows have higher biodiversity, as well as increased risk of asthma.
What kind of biodiversity is seen in the bathroom?
When the toilet is flushed, its contents become aerosolized. Damp towels and sponges are ideal breeding ground for normal and pathogenic microbes. Serratia marcescens, pink residue, is commonly seen on shower curtains... can get removed by washing them. Soap scum, a biofilm, is also seen on shower tiles.
How effective is cleaning in the relative distribution of microbes in a public restroom?
It makes almost no difference. Public bathrooms recolonize completely after one hour of being cleaned.
What is MetaSUB and what are the goals of MetaSUB?
Microbial sampling & sequencing of mass transit systems across the globe. Goals: create geospatial metagenomic and forensic genetic maps identify & track antimicrobial resistance markers in urban-built environments identify novel biosynthetic gene clusters for drug discovery.
What is the rumen? What are the important roles of rumen microbes?
One of the four parts of a cow's stomach. Roles of the microbes there are: degrade plant cellulose (cellulose gets fermented), convert non-protein nitrogen into useable forms, and production of Methanosarcina barkeri gas
What do farm silos do?
Ferment green foliage for feed for cows, which makes it easier to digest. They use manufactured inoculants with a low pH that prevent spoilage. Lactic acid bacteria is a key component used. Silage effects the amount of methane produced by cows.
What effect do livestock antimicrobials have on the environment?
90% gets secreted into the environment and persists there. This increases methane released into the environment and alters the microbiota of surrounding organisms. Manure contains antibiotic resistant bacteria that gets released, and leaches into groundwater, which can effect surrounding crops.
What effect does drying, heating, and water treatment have on antimicrobials found in manure?
Drying increased antimicrobial resistance in bacteria found in manure. Heating helped a little. Water treatment did not have an effect.
What is fermentation? Explain the chemical process of how this happens.
Metabolic process that converts sugar to acid, gases, and/or alcohol in the absence of oxygen. When yeast in present, so is glucose typically. Glucose gets turned into pyruvate in the process of making ATP, but when there is no oxygen available, pyruvate ferment.
What are benefits of fermentation?
A method of preservation, as well as a way for our bodies to access certain nutrients.
What is kimchi and what are the microbes involved in its production?
Produce packed tightly in a container, originally buried in the ground to pickle. Microbes involved are: Lactobacillus, Leuconostoc, Weissella, which produce lactic acid, acetic acid, CO2 & alcohol.
What is pickling and what kind of acid in involved in the process of pickling?
Purposefully creating a salty environment lacking in oxygen to encourage useful microbes to grow and discourage spoilage-causing microorganisms. Lactic acid bacteria is used in pickling because is digests sugars and controls the growth of other microbes.
How is cheese made?
Coagulating diary using heat, rennet, or commonly, lactic acid bacteria such as Lactococcus & Lactobacillus spp. In the U.S. pasteurized milk is used. Rennet in an enzymatic mixture found in cow's stomachs that causes proteins in milk to curdle. Maturation of cheese is similar to development of an ecosystem.
What are the seven steps of beer making? Describe each one
1. Malting: primary sugar produced due to germination of grains is maltose
2. Mashing: malt+water is cooked and enzymes and carbohydrates may be added for more sugar (wort)
3. Brewing: flavor is extracted from hops
4. Filter solids and add yeast
5. Fermenting
6. Conditioning
7. Add priming sugars
What is the principle microbe used in beer production? What differs in the process of making beer vs liquor?
Saccharomyces spp. Other spirits may use distillation.
Describe the 6 steps of making wine
1. Must: crush grapes and skins and treat with sulfur dioxide to kill wild yeast
2. Starter: principle microbes (Saccharomyces, Leuconostoc, Lactobacillus) get added to must
3. Fermentation
4. Wait. Then press ferment to remove solids.
5. Transfer wine in barrels to age
6. Bottle and age
What is terrior and what factors influence it?
Environmental factors that influence a crop's phenotype, including: climate, soil, terrain, tradition
How is sourdough bread made?
Microbes used are: Saccharomyces cerevisiae, Candida spp., Lactobacillus spp. These microbes convert sugar to lactic and acetic acid, which lowers pH to 3.8, which is tolerable for yeast. Cool fermentation can be used to slow the process and release more flavors.
How are cacao beans fermented?
First, sterile white pulp begins to oxidize. Then, yeast is introduced- Saccharomyces cerevisiae breaks down sugars in anaerobic environment produces ethanol & CO2. Lactobacillus & Streptococcus grow ... lactic acid levels increase. Acetobacter & Gluconobacter grow and beans are stirred to add oxygen ... acetic acid.
What are probiotics and prebiotics? What does symbiotic mean?
Probiotics are live, active microbial cultures. Prebiotics are non-digestible carbohydrates (NDO's) in food that promotes growth of 'good' microbes within gut - may enhance absorption of calcium & magnesium. Products that contain both are symbiotic.
What are the four principles of food safety?
1. Cook at the right temperature
2. Wash hands and surfaces often
3. Refrigerate promptly
4. Don't cross-contaminate
Describe 6 ways to prevent food spoilage discussed in class.
1. Industrial canning using high heat and pressure.
2. Desiccation: reducing water content in food, which reduces microbial ability to grow.
3. Freeze drying
4. Pasteurization: using heat to kill off pathogenic bacteria
5. Irradiation of bacteria using light rays
6. Bacteriophages... target, infect and destroy bacteria
What is the difference between pasteurization and ultrapasteurization? What is shelf-stable milk?
Pasteurization: most milk is held at 72°C for 15 sec. High Temperature, Short Time (HTST).
Ultrapasteurization: 140°C for 3 sec. ... provides a longer shelf life but it still needs to be refrigerated - ultra-high temperature (UHT).
Shelf-stable: milk is heated (UHT) with sterile equipment, filled aseptically & hermetically sealed temperature and time necessary to aseptically.
What kind of light rays are used in food irradiation?
Gamma rays, X-rays, and electron beams.
What are GRAS?
Chemical agents added to prepared food and generally recognized as safe. Organic, Kosher, Halal, etc.
During what time of year do food borne illnesses increase?
In summer
How do microbes survive in stomach acid?
Some microbes have no problem surviving in highly acidic environments. Some produce enzymes, capsules, toxins, and other virulence factors that protect them.
What is norovirus?
Leading foodborne illness, a very contagious disease, can get it from an infected person, contaminated food or water, or touching contaminated surfaces. Shed in stool of infected people.
What is Salmonellosis?
Infection with salmonella bacteria, commonly caused by contaminated food or water from poultry or eggs. Can also come from water, soil, animals, air, workers, & equipment.
What is Clostridium perfringens?
AKA food poisoning, associated with cafeteria foods in steam tables ... meats, meat products, & gravy normally found in intestines of animals & humans. It is spore-forming and ingesting large numbers of C. perfringens leads to sufficient toxin that continues the illness.
What is Campylobacter spp. - Gastroenteritis?
A very common cause of diarrhea, often goes unreported. 1/1000 persons will develop Guillain-Barré syndrome and become paralyzed. Birds & cows often have Campylobacter in their intestines ... spread by feces in the water.
What is Staphylococcus aureus - Food Poisoning?
Found in the nose and throat of 25% of people. Heat-stable enterotoxins ... cause intestinal inflammation, decreased water absorption in intestines, triggers neurons to stimulate vomiting. It is fast acting, sometimes causing illness in as little as 30 min. ... symptoms usually develop within one to six hrs. after eating contaminated food.
Clostridium botulinum
Botulism... found in honey, herbs, improperly canned foods. The spores produced are especially toxic to children under one year old.
Shiga-Toxin Producing E. coli (STEC) symptoms
Bloody diarrhea
Listeria monocytogenes - Listeriosis
serious if infection spreads beyond GI tract ... could result in death... can continue to grow in fridge.
Does raw milk carry pathogens?
Listeria, Salmonella, E. coli are commonly found in raw milk. Raw milk products cause 100X more outbreaks
What organizations decide which foods get recalled?
FDA & FSIS: decide how food will be recalled ... monitors process
What are the "benefits" of the use of bioweapons?
They are cheap to produce, they can be deadly quickly and in small amounts, they have a high impact, many are not easy to detect at all, many are inhaled, they don't damage buildings, they produce panic, and they can be hard to get rid of.
How did Japan test biowarfare in China in the 1930s and 1940s?
They infected walls with cholera, they air dropped infected fleas, and they aerosolized anthrax
What are some examples of biowarfare in America?
In the 80s, a cult in Oregon purposefully sprinkled Salmonella on salad bars. In 2001, anthrax-laced letters were sent out.
What are the four criteria for assessing a biological threat?
1. Public health impact: can our health care system support us? Is there a place to dispose of bodies?
2. Delivery potential: how the pathogen spreads and how impactful it is.
3. Public perception: does it cause panic?
4. Preparedness/public health preparedness: are there surveillance measures in place?
What are the categories of bioweapons? Name an example of each.
1. Category A: highest risk... Tularemia
2. Category B: moderate risk... Q fever
3. Category C: potential threats... Hantavirus pulmonary syndrome
What is Tularemia?
-Pathogen: Francisella tularensis
-Very virulent, but low mortality, spread by animal bites, inhalation, contaminated foods.
-category A because very low amount of pathogen is needed for infection
What is Q fever?
-pathogen: Coxiella burnetii
-highly contagious amongst livestock, very infectious, but not fatal
-stable outside the body
-causes panic and fear
What is hantavirus pulmonary syndrome?
-carried by rodents... bites, urine, feces
-fatal 1/3 of the time
-no vaccine
-Category C because it is difficult to weaponize
What are ways that animals have been bio-weaponized?
-infected have been thrown into walled cities, as well as water supply
-infecting food animals
What are some of the pros and cons of Agroterrorism?
Pros: often pathogens already exist in soil and are easy to weaponize. Many are safe to be handled
Cons: mass culling... not always sustainable, easy or cheap. Causes destruction of genetic stock and a lot of dead animals.
What is foot-and-mouth disease virus (FMDV)
A highly contagious disease of cloven-hoofed domestic livestock and wildlife animals... animals are usually culled, although not fatal. Prevalent in many parts of the world, easy to access.
What are plant pathogens?
Severe crop loss due to spread of plant-based toxins. A lot of damage can occur before it is recognized for a response.
What is Rice blast?
Naturally occurring fungus that is easy to disperse and resistant to chemical treatment. So harmful because so much of the world is so dependent on rice. Could result in devastating starvation.
What is project BioShield?
Goals: create stockpiles of medical countermeasures to bioterrorism, including vaccines and protective equipment.
What does Homeland Security do to protect us against bioterrorism?
provides funds and incentives to companies to develop countermeasures
What is biosecurity?
procedures intended to protect humans or animals against disease or harmful biological agents... strategic and organized.
What is Heparin and why is there an imminent risk of global shortage?
Heparin is an anticoagulant (blood thinner) that prevents the formation of blood clots. Heparin is used to treat and prevent blood clots caused by certain medical conditions or medical procedures. African swine fever, which has a major impact of both wild boars and small pig farms, poses a threat of global heparin shortage. This is because we use pigs to make heparin.
What are extremophiles?
Organisms that can live in extreme chemical, physical, or geochemical environments.
What are some reasons we study extremophiles?
Drug discovery, environmental clean-up, innovations to combat global warming, help to understand what defines "life"
What are psychrophiles?
Microbes that live in extreme cold. We study them for biotech purposes.
What are some of the challenges for live for psychrophiles and how do they overcome them?
Some of their challenges to life include reduced enzymatic activity, which has forced enzymes to evolve, reduced membrane fluidity which which resulted in lipid variation, formation of intracellular life which has caused them to develop antifreeze proteins, and reduced rates of transcription, translation, and cell division.
What are ice binding proteins?
They exist on the tip of flagella and enable bacteria to cling to ice.
What are radioresistant microbes and why do we study them?
Microorganisms with the ability to survive high doses of radiation are known as radioresistant or radiation-resistant extremophiles. We study them because their ability to repair DNA could have diverse applications; ability to digest complex plant polymers may have applications in biofuel production and green chemistries.
What is D. radiodurans? What protective features does it have?
(Bacteria - polyextremophile): protects its proteins from ionizing damage, but not DNA. Has multiple copies of genome ... proteins can repair DNA breaks efficiently.
What is T. gammatolerans?
(Archaea): lives near deep sea thermal vents ... requires sulfur for growth.
Unclear how it survives high radiation ... not DNA repair mechanisms; unknown protein(s)?
Describe the fungi found growing around Chernobyl.
Some of it is radiotrophic, meaning it grows towards radioactivity. Increased melanin production was found in these microbes, with melanin that was able to convert gamma radiation into energy.
Why do we study radio resistant fungi?
new drugs could be isolated that could aid in prevention and/or treatment of radiation sickness; genes that could be transferred to plants to make radioresistant
What are some challenges for life for thermophiles and hyperthermophiles and why do we study them?
Challenges to life include: evolving to produce heat-stable enzymes and proteins, as well as evolving to have a membrane rigid enough to protect them. We study them because many important enzymes & proteins have been isolated from these microbes that have advanced biotechnology-related fields.
What are halophiles and why do we study them?
Microbes that grow in very salty conditions and belong to one of 3 categories: 1) Slightly salty 2-5%; 2) Moderately salty 5-20% and 3) Extremely salty 20-30%.
We study them because we can look into cloning halotolerant proteins into other species ... develop salt tolerant crops; biodegrade/bioremediate hazardous compounds.
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