Bacteria Genomes - SYNECHOCOCCUS ELONGATUS

Synechococcus elongatus is a freshwater unicelluar oligotrophic cyanobacterium , Synechococcus is among the most important photosynthetic bacteria in the marine environment, estimated to account for about 25 percent of the primary production that occurs in typical marine habitats. Unlike other photosynthetic prokaryotes, it use chlorophyllA (as do plants) and water as the source of electrons to reduce CO 2 to carbohydrate. Formerly named Anacystis nidulans it has a 2.7-Mb chromosome.

The factors that control their growth directly impact oceanic processes, such as the marine carbon and nitrogen cycles. Cyanobacteria, including species of Synechococcus, Prochlorococcus , Trichodesmium , and Crocosphaera , are prominent constituents of the marine biosphere that account for a significant percentage of oceanic primary productivity.

Iron is an essential trace element for all bacteria. Despite their environmental importance and the belief that Fe (ferric iron) limits their growth in many regimens we know very little about how open-ocean cyanobacteria acquire Fe. Recent work has indicated that primary production in the equatorial Pacific Ocean is limited by Fe bioavailability, thereby implying that Fe may be an important limiting factor for open-ocean cyanobacterial growth in other regions of the ocean. Determining how these microorganisms respond to Fe stress and how they acquire Fe from the environment will provide insights into the factors that limit their growth and greatly increase our understanding of how marine Fe cycling impacts oceanic processes.

The comparison between the genomes of two Prochlorococcus ecotypes and Synechococcus may help elucidate the key factors that regulate species diversity, and the resulting biogeochemical cycles, in today’s oceans.

Biological rhythmicity and the clock mechanisms that drive biological rhythms are fundamental properties of all groups of cellular life, ranging from prokaryotes to humans. These biological clocks time specific molecular, physiological, and behavioural events to optimise their phase relationships relative to the time of day (circadian) and time of year (circannual). The identities of individual clock components or genes suggest that clock mechanisms may have evolved multiple times in the history of life on Earth. Analysis of the cyanobacterial clock in Synechococcus appears to show that all of transcription is rhythmic and that regulation by the clock loci kai (which bear no relationship to per , frq or any of the genes isolated in eukaryotes) occurs at several levels to determine circadian period and phase.

References:

http://genome.jgi-psf.org/draft_microbes/synel/synel.home.html
http://www.tamu.edu/clocks/
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