lecture 4 spring 09 - Microbial Diversity Microbes are everywhere Different habitats provide-Controlling factors selection different physical attributes

lecture 4 spring 09 - Microbial Diversity Microbes are...

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Microbial Diversity
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Microbes are everywhere Different habitats provide different physical attributes and different nutrients. -Controlling factors, selection Thus, the microbial community varies depending on the habitat.
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Think microscopically
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Soil Particle Silt, sand, rock Organic matter Microbes Aerobic and anaerobic zones
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Soil- what’s limiting microbial diversity? Large amount of complex organics Dead plants and animals, waste Moderate temperature (4- 45°C) Moderate pH Heterogeneous environment Gradients of chemicals (oxygen) Two general layers Surface
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Microbial Diversity of Soil Dizzying numbers 1-10 billion cells per gram of soil 3,000 to 106 species Most are uncharacterized!
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DEGRADATION of soil nutrients requires microbial collaboration: Depolymerization - Fungi, Streptomyces. Cytophaga, Bacillus, Clostridium
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Marine ecosystems (surface) Physical parameters Light exposure (to 150 m) Temperature 4 - 37°C pH - about 7.6 Nutrients Ions - Na+, Cl-, Mg2+, SO42-, Ca2+, K+, HCO 3 - Low in organic matter vs soil
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Marine Microorganisms Photosynthetics dominate Synechococcus Prochlorococcus Trichodesium SAR86 (not cultured) Proteorhodopsin for energy from light Important primary producer (provides for other microbes) Bloo ms Trichodes ium
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Marine Microorganisms cont. Chitin degraders very important Chemoheterotrophs Alteromonas Marinomonas Photobacterium and Vibrio Pelagibacter ubique Previously unculturable 25% of ocean biomass Grows on dilute nutrients @ 15°C, 23 days to grow up Small Vib rio Photobacte rium
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  • Spring '09
  • kaspar/escalnte/downs
  • Microbiology, Bacteria, Sargasso Sea, Appl Environ Microbiol.

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