Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Microbes In Aquatic Marine Ecosystem

Related Books

Free with a 30 day trial from Scribd

See all
  • Be the first to comment

Microbes In Aquatic Marine Ecosystem

  1. 1. Microbes in Aquatic Marine Ecosystems Joemar C. Taganna MS Microbiology
  2. 2. Introduction <ul><li>The oceans and seas: The largest aquatic system, covering 70% of the earth’s surface </li></ul><ul><li>Includes oceans, estuaries, salt marshes, lagoons, tropical communities, rocky subtidal and intertidal ecosystems </li></ul><ul><li>Home to a host of different species ranging from tiny microbes to huge mammals </li></ul>
  3. 3. Introduction (cont.) <ul><li>While microbes are not visible, they account for more than 90% of ocean biomass and constitute a hidden majority of life that flourishes in the sea </li></ul><ul><li>But much of this microbial life is still unknown because of difficulties in growing them in a culture and in observing them in nature </li></ul>
  4. 4. Introduction (cont.) <ul><li>Differ from freshwater environments in many ways (salinity, average temperature and nutrient status) </li></ul><ul><li>Nutrient levels in the open ocean are often limiting, specially N, P and Fe </li></ul><ul><li>But still, the collective photosynthesis and O 2 production here are major factors that affect many ecological systems on Earth </li></ul>
  5. 5. Chlorophyll in the oceans and vegetation on land throughout the world. Source: The SeaWiFS Project, NASA/Goddard Space Flight Center and ORBIMAGE
  6. 6. The Inshore and Open Ocean Microbiology <ul><li>Inshore ocean areas: More dense than open ocean areas since it is more nutritionally fertile </li></ul><ul><li>Denser populations can be found in marine bays and inlets that receive high levels of nutrients from sewage or industrial waste runoff </li></ul>
  7. 7. <ul><li>In severe pollution, shallow marine water can become anoxic from the consumption of O2 by bacteria </li></ul><ul><li>And also, the water become toxic due to the production of H2S by sulfate-reducing bacteria that quickly thrive in anoxic seawater </li></ul>http://serc.carleton.edu/.../red_tide_genera.v3.jpg http://www.algae.info/bgreenbloom.jpg
  8. 8. <ul><li>Open Oceans: Has low inorganic nutrient and organic carbon levels so life is relatively scarce </li></ul><ul><li>10 5 - 10 6 prokaryotes and 10 4 per ml eukaryotes </li></ul><ul><li>How do these organisms survive? </li></ul><ul><ul><li>Oxygenic and aerobic anoxygenic photosynthesis ( Prochlorococcus, Trichodesmium and Ostreococcus ) </li></ul></ul><ul><ul><li>Proteoredopsin: Converts light energy to ATP </li></ul></ul><ul><ul><ul><li>Previously only known in Halobacterium </li></ul></ul></ul><ul><ul><ul><li>A process that enables life in oligotrophic environments </li></ul></ul></ul>
  9. 9. Prochlorococcus Ostreococcus Trichodesmium science.compulenta.ru/.../f46/trichodesmium.jpg http://bioinformatics.psb.ugent.be/ http://arep.med.harvard.edu/
  10. 10. Archaea/Bacteria distribution: <ul><li>Phylogenetic stains </li></ul><ul><li>Bacteria dominate among phototrophs - photic zone (top 300 m) </li></ul><ul><li>Archaea ( Crenarcheota ) in deep oceans </li></ul><ul><li>In the world oceans: </li></ul><ul><li>1.3x10 28 Archaea and 3.1x10 28 Bacteria </li></ul>
  11. 11. Deep-sea Microbiology <ul><li>0 - 300 m; the photic zone </li></ul><ul><li>300 - 1000 m; chemotrophs and psychrophiles; 2 - 3 o C </li></ul><ul><li>< 1000 m low activities (cold, high pressure,scarce nutrients) microbes are: psychrophiles, barophiles, oligotrophs </li></ul><ul><li>How do we study the deep oceans? - submersibles </li></ul>
  12. 12. Barotolerant and barophilic bacteria: <ul><li>Barotolerant (3 km) vs. barophiles (4 - 6 km) vs. extreme and obligate barophiles (10 km) e.g., Moritella : cannot tolerate decompression and grows optimally at 2 o C </li></ul><ul><li>10 m = 1 atm </li></ul><ul><li>Mechanisms: </li></ul><ul><ul><li>Increased substrate binding capacity of enzymes </li></ul></ul><ul><ul><li>Increased unsaturation of fatty acids in membranes </li></ul></ul><ul><ul><li>Pressure controlled gene expression (e.g., OmpH) </li></ul></ul>
  13. 13. Hydrothermal Vents <ul><li>Sea floor spreading centers (rifts) </li></ul><ul><li>Warm vents (6-23 o C) </li></ul><ul><li>Hot vents (270 - 380 o C) - “black smokers” </li></ul><ul><li>Ecosystem is energized by chemical energy </li></ul><ul><li>Steep gradients </li></ul>
  14. 14. Deep-sea vent communities: <ul><li>How can life exist at 380 o C and at extremely high pressure? </li></ul><ul><li>Symbiosis of animals with chemoautotrophic bacteria H 2 S, H 2 , NH 4+ , Mn 2+ , CO </li></ul><ul><li>Animals: Giant tubeworms, clams and mussels </li></ul><ul><li>Microbes present here are sulfur oxidizers ( Thiobacillus , Begiatoa, Thiomicrospira, Thiothrix ) </li></ul>
  15. 15. Source: http://www.biosbcc.net/ocean/marinesci
  16. 16. Nutrition of vent animals: <ul><li>Animals fed on bacterial products and biomass </li></ul><ul><li>Endosymbiotic bacteria are located in trophosomes (3.7x10 9 cells per g) - pure cultures found these to be similar to Thiovulum </li></ul><ul><li>Animals produce hemoglobin-like proteins that transport H 2 S, O 2 , and CO 2 to the microbes </li></ul><ul><li>Evidence from sulfur stable isotope signatures (34S/32S) implicating H2S as the S source </li></ul><ul><li>Chemolithotrophic ectosymbionts of Alvinella (Pompeii worm) is also thought to provide nutrients to its host </li></ul>
  17. 17. <ul><ul><li>Alvinella pompejana </li></ul></ul>
  18. 18. Superheated water: black smokers <ul><li>Water at 450 o C rich in metal sulfides </li></ul><ul><li>“ Chimney” is formed when metal sulfide precipitate </li></ul><ul><li>Hydrothermal fluid is sterile (no life at > 150 o C) </li></ul><ul><li>Steep physical chemical gradient through the chimney’s wall </li></ul><ul><li>Where the most hyperthermophilic Archaea ( Methanopyrus , Pyrolobus and Pyrodictium ) live </li></ul>
  19. 19. References <ul><li>Madigan, M.T., Martinko, J.M. and Parker J. 2003. Brock Biology of Microorganisms , 10 th ed. Prentice Hall: New Jersey, USA. Pages 643-651 </li></ul><ul><li>Partensky, Hess and Vaulot. 1999. Prochlorococcus, a Marine Photosynthetic Prokaryote of Global Significance. Microbiology and Molecular Biology Reviews, vol. 63, no. 1, pages 106-127 </li></ul><ul><li>Environmental Protection Agency (EPA). 2006. Marine Ecosystems. Accessed on Nov 19, 2006 from http:// www.epa.gov/bioindicators/aquatic/marine.html </li></ul><ul><li>Birgit, Reinert. 2002. Marine Microbes: Genomic tools reveal unexpected diversity of ocean life. Accessed on Nov 20, 2006 from http://www.genomenewsnetwork.org/articles/03_02/ocean_diversity.shtml </li></ul><ul><li>Touchette, Nancy. 2003. How the Other Half Lives: Marine Microbes Capture the Limelight. Accessed on Nov 20, 2006 from http://www.genomenewsnetwork.org/articles/09_03/ocean.shtml </li></ul>
  20. 20. Thank you for listening!

×