The M icrobial W orld

1. The Microbial World Chapter 5

2. Prokaryotic Metabolism • Autotrophs • Heterotrophs

3. Autotrophs • Some bacteria and archaea make their own organic compounds • Primary producers • If they do photosynthesis it takes place in on folded membranes in the bacteria cell • Photosynthetic bacteria account for much of the primary production of open ocean • Other bacterial autotrophs- chemosynthetic bacteria

4. Heterotrophs • Most marine bacteria are heterotrophs • Heterotrophs obtain energy from organic matter by respiration • Respiration in aerobic bacteria and archaea use oxygen • In Anoxic sediments bacteria use anaerobic respiration

5. Nitrogen Fixation • Bottom dwelling and planktoniccyanobacteria carry out nitrogen fixation • Nitrogen fixation N2 NH4 (covert nitrogen to ammonium) • Ammonium is then transferred into NO3- (nitrate) and other N compounds • These N sources can be used by primary producers

6. Unicellular Algae • Algae – very diverse group (mostly aquatic, mostly photosynthetic) • Eukaryotic- cells have a nucleus, organelles • Photosynthesis- Chloroplast • Lack true leaves, stems, roots • Have plant and animal characteristics- Protista

7. Diatoms • Unicellular but they can be colonial or form groups or chains • In a shell made of silica frustule (2 halves) • The perforations allow dissolved gases and nutrients to enter and exit • Coloration- carotenoid pigments (few are colorless) • Photosynthetic factories • Some are toxic

8. Diatom Reproduction • Asexual reproduction • Auxospores- resistant stages that eventually give rise to larger cells that display the frustule characteristic of the species **get smaller each division** • Favorable conditions- bloom • Diatomaceous ooze- dead diatoms sink and form thick deposits of siliceous material

10. Dinoflagellates • Large group of planktonic unicellular organisms • 2 flagella, cell wall, plates • Photosynthesize and ingest • Reproduction is almost exclusively by cell division • Bioluminescence • Toxic

11. Protozoans (animal like protists) • Eukaryotic • Structure is simple • Animal like • Protozoans comprise several groups of unrelated origins • Heterotrophs and some photosynthesize

12. Foraminiferans • Type of marine protozoan • Have a shell (test) made of CaCO3 • Pseudopodia- extensions of the cytoplasm • Live on the bottom either free or attached • Shells of bottom forams are important contributors to calcarious material • White cliffs of Dover

13. Radiolarians • Planktonic marine protozoans • Secrete shells of glass and other materials • Typical shells are spherical with radiating spines • Sausage shaped colonies • When they die and sink to the bottom they become silicious ooze • Resistant to dissolving under pressure

14. Ciliates • Protozoans • Lots of hair like extentions • Locomotion and feeding • Found all over seaweeds and in bottom sediments • Live in gills of clams, urchin intestines,skin of fish

15. Fungi • Eukaryotic and mostly multicellular • Molds, yeasts are unicellular • They are heterotrophs that lack chloroplasts • 500 species of marine fungi (most are microscopic) • Decompose detritus • Some are parasites • Some form symbiotic relationships with algae • lichens

16. Microbial world Prokaryotes Eukaryotes • Bacteria • Cyanobacteria (stromatolites) • Archaea • Extremophiles • Diatoms • Dinoflagellates • Protozoans (animal like) • Foraminierans • Radiolarians • Fungi

17. Presentation • Row 1 –Diatoms • Row 2- Dinoflagellates • Row 3- Foraminiferans -Row 4 Radiolarians • Row 5- Ciliates • Row 6- Fungi • Row 7: Cyanobacteria

18. Poster Rubric • Image • Definition • At least 5 facts • Importance to marine environment/role in marine environment • ** this will be a graded assignment**