The Microbial WorldChapters 5, 15

The Marine Environment

Plankton Collection

Plankton Classification

• Megaplankton 20-200 cm

• Macroplankton 2-20 cm

• Mesoplankton 0.2-20 mm

• Microplankton 20-200 μm

• Nanoplankton 2-20 μm

• Picoplankton 0.2-2 μm

Metabolism

• Metabolism- all chemical reactions that occur in an organism.

• Autotrophic- requiring carbon dioxide and a source of energy for the synthesis of organic molecules (glucose).– Photoautotrophs- absorb light energy from the sun.

– Chemoautotrophs- derive energy from chemical compounds.

• Heterotrophic- requiring complex organic compounds; obtains energy by consuming organic matter.

Bacteria and Archaea

Photosynthetic Prokaryotes

• Kingdom- Bacteria– Phylum- Cyanophyta

Cyanophyta

• Characteristics

• Examples- Oscillatoria, Synechococcus, Synechocystis.

Cyanobacterial Cell

Cyanophyta- Gram Negative Bacteria

• Gram positive- peptidoglycan layer; stains with crystal violet.

• Gram negative- peptidoglycan layer sandwiched by lipopolysaccharide and protein layers; does not stain with crystal violet.

Global O2 from photosynthesis

• 80% comes from marine cyanobacteria.– Synechococcus– Synechocystis

• 20% comes from terrestrial systems.– 5% of this comes from tropical rainforests.

Stromatolites

Archaea

• Prokaryotic

• Extremophiles– Hydrothermal vents– Hypersaline basins– Highly acidic env.– Highly alkaline env.

Photosynthetic Protista (the algae)

• Dinophyta- dinoflagellates.

• Haptophyta- haptophytes.

• Heterokontophyta- heterokont algae.– Xanthophyceae- yellow-

green algae.– Bacillariophyceae-

diatoms.

Dinophyta- dinoflagellates

• Characteristics

• Examples- Ceratium, Pfiesteria.

Pfiesteria piscicida

Haptophyta- haptophytes

• Characteristics

• Examples- Prymnesium, Phaeocystis.

Heterokontophyta- heterokonts

Xanthophyceae- yellow-green algae

• Characteristics

• Examples- Vaucheria.

Bacillariophyceae- diatoms

• Characteristics

• Examples- Coscinodiscus, Chaetoceros.

Frustule Morphology

The Protozoans

• Granuloreticulosa- foraminiferans.

• Polycystina- radiolarians.

• Ciliophora- ciliates.

Granuloreticulosa- foraminiferans

• Characteristics

• Example- Globigerina.

Pink Beaches of Bermuda

Polycystina- radiolarians

• Characteristics

• Example- Hexacontium.

Various Radiolarians

Ciliophora- ciliates

• Characteristics

• Examples- Strombilidium, Tintinnopsis.

Fig. 5.14

Kingdom Fungi

• Characteristics

• Example- Aspergillus.