Synechococcus and Biofuel

Synechococcus is a genus of unicellular marine cyanobacteria that are found in both freshwater and marine water environments. They comprise a vast majority of picoplanktonic marine cyanobacteria. [1] Species in this genus are capable of photoheterotrophic, chemoheterotrophic, photoautotrophic, and even nitrogen fixation. [2] The genomes of several species of Synechococcus have been fully sequenced, most notably Synechococcus elongatus strain PCC 7942 and species strain WH8102. Due to the diversity in its metabolism as well as a genome that can be readily manipulated, Synechococcus holds potential for biofuel production via these metabolic pathways

Introduction

Classification

Taxonomy

Bacteria; Cyanobacteria; Chroococcales; Synechococcus [3]

Cell Structure

Synechococcus are coccoid shaped bacteria that range in size from 0.2-2 µm. They are classified as Gram-negative cells since the cell envelopes of these cyanobacteria structurally resemble those of Gram-negative bacteria, consisting of a cell membrane, peptidoglycan layer, outer membrane, surface layer, and sometimes additional structures. [4] [5]

Membrane structure of Synechococcus (strain WH8113) The inset corresponds to the outlined section of cell envelope comprising cell membrane (CM), peptidoglycan layer (P), outer membrane (OM), and surface layer (S). A thylakoid layer (T) is also indicated. This picture was published in 2001 by Aravinthan DT Samuel, Jennifer D. Petersen and Thomas S. Reese.[6

] Synechococci species are both motile and non-motile, although many motile species appear to accomplish their movement without the aid of a flagella. Cells are thought to undergo locomotion through a gilding fashion, using filamentous protrusions (pili or spicules) to make contact with cell surfaces and move in a direction parallel to the filament (directional motility). [7] Swimming motility is believed to be accomplished by surface waves generated by filamentous protrusions. It is proposed that the waves are generated by a motor force embedded in the cell membrane, although the exact mechanism is unclear. [8]

Metabolism

Discuss various pathways of metabolism

Further Reading

[Sample link] Ebola Hemorrhagic Fever—Centers for Disease Control and Prevention, Special Pathogens Branch

References

[Sample reference] Takai, K., Sugai, A., Itoh, T., and Horikoshi, K. "Palaeococcus ferrophilus gen. nov., sp. nov., a barophilic, hyperthermophilic archaeon from a deep-sea hydrothermal vent chimney". International Journal of Systematic and Evolutionary Microbiology. 2000. Volume 50. p. 489-500.

Edited by (Caitlyn Young), a student of Nora Sullivan in BIOL168L (Microbiology) in The Keck Science Department of the Claremont Colleges Spring 2014.