Bacterial Plankton – Significant Contributors to Chlorophyll Production   
Example organism: Synechoccus species

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  • Domain: Bacteria
  • Kingdom: Bacteria
  • Phylum: Cyanobacteria
  • Class:  Cyanophyceae
  • Order: Synechococcales
  • Family: Synechococcaceae
  • Genus/Species: representative organism – Synechococcus species

Most visitors to CBEC will know that chlorophyll-producing organisms are the basis of the food web, and that without them, no other living organism would exist.  These primary producers are able to convert light energy into biomass, and that biomass is essential to organisms without that capability.  Photosynthetic organisms are also critical for climate control and oxygen production. Many if not most people tend to visualize large vascular plants when they think of photosynthesis, but over 40% of the Earth’s photosynthetic production is performed by phytoplankton, which are single-celled algae (eukaryotic) and bacteria (prokaryotic).

Chlorophyll-producing bacteria are called cyanobacteria.  Cyanobacteria are among the first living organisms to occur on Earth, having evolved approximately 3.5 billion years ago.  Mats of cyanobacteria are the oldest known fossils.  Chloroplasts, the organelles responsible for photosynthesis in algae and green plants, are thought to be endosymbionts,  i.e. photosynthetic bacteria evolved as organelles within eukaryotic cells.

Members of the genus Synechococcus are some of the most prolific and important constituents of bacterial phytoplankton in oceans and estuaries, particularly in temperate and tropical waters.  They have been measured in concentrations exceeding one million cells per milliliter.  Another group of cyanobacteria that is significant in terms of chorophyll production (possibly even more significant than Synechococcus) is the genus Prochlorococcus.  The two genera are similar, but Prochlorococcus is smaller and has evolved a unique light-harvesting complex, employing different pigments than other photosynthetic organisms.

Learn More:

Fundamentals of Environmental Measurements: Algae, Phytoplankton, and Chlorophyll

Introduction to Cyanobacteria: Architects of Earth’s Atmosphere

The Origin of Mitochondria and Chloroplasts

Notes & References:

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