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<p>[[Synechocystis sp. PCC6803 ]] is a freshwater cyanobacterium capable of both phototrophic growth by oxygenic photosynthesis in sunlight and heterotrophic growth by glycolysis and oxidative phosphorylation during dark periods. Transitions of light and dark phases are effectively anticipated by a circadian clock.</p><p>Contents [hide]<br />1 Overview <br />2 Light-activated heterotrophy<br /b>3 References<br />4 Databases<br /> Overview<br />[edit] Overview<br /b>Cyanobacteria are model microorganisms for the study of photosynthesis, carbon and nitrogen assimilation, evolution of plant plastids, and adaptability to environmental stresses. Synechocystis sp. PCC 6803 is one of the most highly studied cyanobacteria as it can grow both autotrophically or heterotrophically in the absence of light. It was isolated from a freshwater lake in 1968 and is easily transformed by exogenous DNA. The photosynthetic apparatus is very similar to the one found in plants. This organism also exhibits phototactic movement.</p><p>[edit] <b>Light-activated heterotrophy<br /></b>It can live completely heterotrophically in the dark, but for yet unknown reasons requires a minimum of 5 to 15 minutes (blue) light per day. This regulatory role of light is intact in both PSI and PSII deficient strains.[1]</p>
<p>NDH-2 is a regulatory quinone:NAD(P)H oxidoreductase[2] global analysis of circadian gene expression indicates that translation genes are expressed at the early subjective day.[3]</p>
<p>Some glycolytic genes are regulated by sll1330 under light and glucose-supplemented conditions. One of the most important glycolytic genes is fructose-1,6-bisphosphate aldolase (fbaA). The mRNA level of fbaA is increased under light and glucose-supplemented conditions. But in Δsll1330, fbaA is not increased under same conditions.[4]</p>
<p> </p><p><b>Paper:</b></p><p>[edit[Sequence Analysis of the Genome of the Unicellular Cyanobacterium Synechocystis sp. Strain PCC6803. II. Sequence Determination of the Entire Genome and Assignment of Potential Protein-coding Regions. DNA research 1996]] <br /> </p><p> </p><p><b>References</b><br />
1.^ Anderson SL and McIntosh L (May 1991). "Light-activated heterotrophic growth of the cyanobacterium Synechocystis sp. strain PCC 6803: a blue-light-requiring process". J Bacteriol 173 (9): 2761–2767. PMID 1902208. <br />
2.^ Howitt CA, Udall PK, and Vermaas WF (July 1999). "Type 2 NADH dehydrogenases in the cyanobacterium Synechocystis sp. strain PCC 6803 are involved in regulation rather than respiration". J Bacteriol 181 (13): 3994–4003. PMID 10383967. <br />