Extremophiles on Earth Lecture 11 Post Midterm No copyright infringement is intended by the creation or use of these notes Hydrothermal Vents o An opening in the earths surface that releases hot water vapor o Found near volcanic activity areas of tectonic plate movements ocean basins and hotspots o Reduced metals and no light depending on depth o Vents that issue black gas are called black smokers because they contain sulfide sulfur attached minerals o Vents that issue a lighter gas are called white smokers because they contain minerals such as barium calcium and silicon these tend to be lower temperatures o Range from 2C to 400C high concentration of hydrogen sulfide and metals Adaptations to Hydrogen Sulfide Tubeworm o Has a highly vascularized tip red plume that exchanges gases with environment CO2 O2 H2S o Worm plume provides essential nutrients to bacteria living in specific organ of the worm and in turn the bacteria converts the gases into organic molecules which the worm can feed on b c it does not have a digestive tract Symbiosis Adaptations to temperature Pompeii Worm o Rests in rear in hot water up to 80C while its head rests in cooler water 22C o Covering its back are glands that secrete mucous that feed bacteria covering the worm s rear The bacteria insulate the worm and protect it from the heat Adaptations to iron sulfides Hot Vent Gastropods o Live at the base of black smokers o Only known animal to use iron sulfide as skeletal material foot is covered with scale shaped sclerites mineralized with pyrite and gregite iron sulfides o Sclerites may be used for protection o Thermophiles or Chemoautotrophs o Produced by the rise of geothermally heated water from the earth s crust o Heated by magma geysers erupt with hot water suddenly b c of heat and o The hot water erupted contains minerals from the earth that precipitate Hot Springs pressure when cool o Geysers Are hot springs that intermittently shoot out water combined by steam Generally near volcanic areas and effect is b c it s close to magma o Springs Temperature Warm Spring 20 40C Hot Spring 40 75C mesothermal 75C hyperthermal travertine CaCO3 forms in mesothermal springs siliceous sinter SiO2 nH2O forms in hyperthermal springs thermophyllic bacterial photosynthesis Cyanobacteria adapted to different temperatures o Thermophiles Photo and Chemoautotrophs Brine Pools o Concentration of water with high salinity in ocean basin o Methane found in high concentration in these areas providing energy to surrounding organisms via chemosynthesis o Called lakes within the ocean b c its so saline and dense that its hard to dissolve into surround areas of ocean o Typically found in Gulf of Mexico Mediterranean and Red sea o Anoxic no oxygen o Hydrothermal activities up to 70C o Not many know adapted organisms o Halophiles Thermophiles Chemoautotrophs Deep Biosphere o In the oceans sediments and on land soil o Half of all prokaryotic microorganisms on Earth are found deep down in o Biomass of sub seafloor microorganisms corresponds to 1 10 to 1 3 of the seabed est 500m Earth s total living biomass o The deeper you get into the seafloor the less activity sulfur reduction rate you get b c microbes have less food o RNA probes can also check activity o High pressure down low o Oligotrophs piezophiles thermophiles Permafrost o Soil at or below freezing point for 2 or more years o 20 of earth s land mass o Active permafrost thaws and refreezes covers permafrost soil o Has a hexagonal shape similar to that of mars o Life Active living in thin active permafrost layer between soil and ice Viable but inactive frozen and suspended for later life deep anabiosis Frozen remains of organisms that died Methanogensis microbes that form methane known as methanogens in permafrost activity down to 13C o Psychrophiles Sea Ice point lower briny habitat o Freezes at a lower temperature than fresh water salt makes the freezing o Bacteria viruses unicellular algae diatom chains and worms live in this o Brine channels in sea ice allow space in ice to let microorganisms live if they can adapt to low temperatures and high salinity o Unicellular algae are the primary producers in the sea ice o Sea ice pores rather than channels form when there is organic matter and microorganisms together o Psychrophiles cryophiles and halophiles Subglacial Lakes o Water under glaciers act as ice shield o Lake Vostok largest Antarctica subglacial lake o Have not looked deep into it b c of the fear of contamination o Found hydrogen utilizing thermophiles o May have chemosynthetic community within the lake b c of geothermal energy from mantle activity or plate tectonics o Oligotrophs chemoautotrophs Acidic Rivers o Form from interaction of pyrite iron sulfide with water air o Ex Rio Tinto in Spain o Supported by microbial activity o Acidophiles chemoautotrophs Other extreme environments o Warm cold deserts no water high low temp high UV radiation o Caves no light no outside nutrition sometime toxic gas stable temp o Intertidal zones desiccation freezing UV radiation change in salinity