(Below N is a link to NCBI taxonomic web page and E link to ESTHER at designed phylum.) > cellular organisms: NE > Bacteria: NE > Terrabacteria group: NE > Cyanobacteria/Melainabacteria group: NE > Cyanobacteria: NE > Oscillatoriophycideae: NE > Oscillatoriales: NE > Microcoleaceae: NE > Arthrospira: NE > Arthrospira maxima: NE > Arthrospira maxima CS-328: NE
LegendThis sequence has been compared to family alignement (MSA) red => minority aminoacid blue => majority aminoacid color intensity => conservation rate title => sequence position(MSA position)aminoacid rate Catalytic site Catalytic site in the MSA DALAGLISQWLWVAFSVFLLWLFLFQLLRIVVYQRDRYRIIHYGAPDLAE FFWRLDKALGDNPYASMPFLPGEQPRLSPLPTLNVNLIGHSMGCLLVVNV LRILSDRFGKEDRLVQQGNDMGEYLRLDRLILSAPDIPLEFLREGRNNYV RSAILRCREIYLFSSDRDLVLRYLSVLGNWFSEPSVAMSG
Reference
Title: Contribution of a sodium ion gradient to energy conservation during fermentation in the cyanobacterium Arthrospira (Spirulina) maxima CS-328 Carrieri D, Ananyev G, Lenz O, Bryant DA, Dismukes GC Ref: Applied Environmental Microbiology, 77:7185, 2011 : PubMed
Sodium gradients in cyanobacteria play an important role in energy storage under photoautotrophic conditions but have not been well studied during autofermentative metabolism under the dark, anoxic conditions widely used to produce precursors to fuels. Here we demonstrate significant stress-induced acceleration of autofermentation of photosynthetically generated carbohydrates (glycogen and sugars) to form excreted organic acids, alcohols, and hydrogen gas by the halophilic, alkalophilic cyanobacterium Arthrospira (Spirulina) maxima CS-328. When suspended in potassium versus sodium phosphate buffers at the start of autofermentation to remove the sodium ion gradient, photoautotrophically grown cells catabolized more intracellular carbohydrates while producing 67% higher yields of hydrogen, acetate, and ethanol (and significant amounts of lactate) as fermentative products. A comparable acceleration of fermentative carbohydrate catabolism occurred upon dissipating the sodium gradient via addition of the sodium-channel blocker quinidine or the sodium-ionophore monensin but not upon dissipating the proton gradient with the proton-ionophore dinitrophenol (DNP). The data demonstrate that intracellular energy is stored via a sodium gradient during autofermentative metabolism and that, when this gradient is blocked, the blockage is compensated by increased energy conversion via carbohydrate catabolism.
