Prokaryotes
Refresher
- 2 Domains
- Bacteria
- Archaea
- Prokaryotic (no true nucleus)
- Peptidoglycan cell walls
- 1-2 µm in size
- 3 basic shapes (cocci, bacilli, spirilli)
- Heterotrophic or Autotrophic (via photosynthesis or chemosynthesis)
Locations
- Bacteria can be found all over the marine environment
- Decay bacteria break down waste products and detritus on ocean floor
- Recycling of organic matter in oceanic food web
- Provide nutrients for bottom dwellers
- Most abundant bacteria in the ocean is SAR11 (35% of all bacteria) - it's also the most common organism on earth (10,000 cells in each drop of water)!
- Read more about SAR11 here!
Cyanobacteria
- AKA Blue-green Algae
- Have chlorophyll and are photosynthetic
- Most have phycocyan - blue pigment
- Some have phycoerythrin - red pigment
- An abundance of the red pigment can lead to "red tides"
- Thought to be important to oxygen consumption
Archaea Characteristics
- Prokaryotic, but genetically more similar to eukaryotes
- Mostly extremophilic
- Thermoacidophiles - hydrothermal vents up to 121°C!
- Methanogens
- Halophiles
- Deep water archaea - can survive at 300-800 atm!
