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Whose Planet Is This, Anyway? Elio Schaechter Dr. Saier’s Class Sept. 28, 2011 Google Blog “Small Things Considered” Microbes: •Are the source of all other life forms •Are much more diverse than plants and animals •Are enormously abundant, about 50% of the total biomass •Grow in virtually everywhere on earth where there is liquid water Number of People on Earth: 6.5 followed by 8 zeroes 6,500,000,000 Number of Bacteria On Earth: about 10 followed by 30 zeroes 10,000,000,000,000,000,000,000,000,000,000 There are about 3 Tons of Bacteria for Every Human Being on Earth! The elephant’s weight is that of the bacteria per human being What would happen if all microbes on Earth went on strike? •Plants would run out of usable nitrogen in about one week •Plants would run out of CO2 in about a year •We’d start to run out of food in less than a year •We’d gradually lose the oxygen in the air •Our climate would change drastically (in ways difficult to predict) The White Cliffs of Dover Microbial mats the size of Alabama In 1998, Thomas Gold, wrote a highly influential book, The Deep Hot Biosphere. •there is abundant microbial life in the water within the pores, cracks and fissures of the rocks beneath our feet. • hydrocarbons were not derived from fossils but rather were created early in the life of the planet by chemical and physical processes below the crust, including radiation. How to study this: begin at a deep hole in the ground, such as a gold mine several kilometers deep. Drill for water, discard the first few day’s flow. Find ~ 3-4 104 bact/ml. Oxidize H, reduce sulfate Desulfotomaculum predomintes (10% of spores survive 15 min at 140° C) Li-Hung Lin et al (Int’l consortium). Science, 2006 Single cells in populations – substrate tracking autoradiography fluorescence in situ hybridization (STARFISH) simultaneously detects specific cell types via 16S rRNA probe and activity via microautoradiography Single cells in isolation – •nano-cell biology ultrahigh resolution fluorescence microscopy + quantum dots, electro cryo-tomography, Raman spectroscopy + metallic nanoparticle-FRET •single cell genome sequencing Short Break Microbes Influence the Weather Everybody is always talking about the weather Negative feedback loop: the more DMS is made, the more clouds are formed, the less sunlight shines on the ocean, the less photosynthesis is carried out, the less DMSP is made, the less DMS is produced, etc. Todd JD et al. Science 2007 DMSP=dimethylsulfoniopropionate A few more cheerful facts about DMSP and DMS •Some large seaweeds also make DMSP and have DMSP lyase •DMS and acrylate may deter grazing by herbivores (zooplankton grazers prefer algae without DMSP-lyase) Zooplankton, including krill, feed on phytoplankton blooms, releasing DMSP, which becomes DMS. Higher DMS above the ocean is an indication of zooplankton. Seabirds are also seen in areas with high DMS. Do they smell it? Is DMS a foraging clue? (Releasing DMS in the air or on slicks attracts some species of petrels and others) Extremophiles Bacteria Of Boiling Hot Springs In Yellowstone National Park Photosynthetic bacteria and lichens in Antarctic sandstone Algae in silica granule from Yellowstone (pH 1.0) The reactor at Chernobyl The “Chernobyl mold” This fungus grows better with radiation SYMBIOSES Prokaryotic symbiosis Red:archaea (CH4 + 2 H2O CO2 + 4 H2) Green; bacteria (5 H2 + SO42- H2S + 4 H2O) Deep sea Hydrothermal vents • BIOFILMS • VIRUSES Abundance of Organisms in 1 mL of Seawater Zooplankton <<1 Phytoplankton Algae 3,000 Protozoa Photosynthetic 4,000 Bacteria Heterotrophic Bacteria V i r u s e s/ Phage 100,000 1 ,000,000 10,000,000 Ecological Roles of Marine Phage • Most common predator in the ocean ~107 phage ml -1 vs. ~10 -19 great white sharks ml-1 • Major players in global C and nutrient cycles • Transduction and lysogenic conversion - 1025-1028 base pairs of DNA per year in the oceans - Vibrio cholerae Culture based studies are limited because >99% of the marine bacterial hosts are not readily cultured Forest Rohwer this is equivalent in weight to 75 million blue whales! wow! Curtis A. Suttle One teaspoonful of ocean water contains about one million bacteria The total amounts to the weight of about 100 million Blue Whales! Thanks for Listening