Report: Marine Symbiosis

James McClung

Biomedia Report: Term 3

Article:
     Unusual Symbiosis in Marine Microorganisms Fertilizes Ocean by Fixing Nitrogen
URL:
     http://www.sciencedaily.com/releases/2012/09/120920141141.htm
By:
     ScienceDaily

Summary:
     Recently, scientists from the University of California, Santa Cruz, have managed to identify a mutualistic bond between nitrogen-fixing cyanobacteria and single-celled algae in marine environments. It appears these two species play a key role in providing their ecosystem with usable nitrogen. The algae plays host to the bacteria as the two cooperate to fix nitrogen from the atmosphere into a useful form. Interestingly, the cyanobacteria has no photosynthetic capabilities, which scientists hypothesize is a result from having such a close connection with the algae, which can photosynthesize. In other words, the cyanobacterium, whose ancestors evolved into chloroplasts, no longer needs to photosynthesize. The algae provides it with carbon, and it provides the algae with nitrogen.
     Although the cyanobacteria found in the green algae are probably completely dependent on the green algae for survival, it is not yet considered an organelle. Perhaps the most interesting part of the discovery of these species' unique symbiosis is that the cyanobacteria may be evolving to become an organelle, just like the mitochondria and chloroplasts did so long ago. It would be completely unique from these two, as it does not process or create food, it fixes nitrogen.

Connection:
     In class, we are currently learning about the evolution of plants, among other things. Plants evolved from green algae, which we recently learned as part of plants' evolution. The green algae and cyanobacterium involved in the mutualistic relationship are evolving to completely rely on each other for survival, as did early cells and chloroplasts that eventually became plants as we know them today.

Citation:
     University of California - Santa Cruz. "Unusual symbiosis in marine microorganisms fertilizes ocean bu fixing nitrogen." ScienceDaily, 20 Sep. 2012. Web. 7 Mar. 2013.