The positive charge on sodium prevents the negative charges from repelling each other and lysing the cell. Sugars proceed through the glycolytic cycle and then to the citric acid cycle. When these halophiles are changed from a high oxygen environment to an oxygen-limiting environment, bacteriorhodopsin is incorporated into their cell membranes. Bacteriorhodopsin absorbs light at 570 nm. The retinal chromophore is normally in the all trans form.
Light excites the molecule into the cis form.
This energy is transferred to a proton motive force coupled to ATP synthesis. These groups are the Thermococcus , Pyrococcus , Methanopyrus , Archaeoglobus and Ferroglobus . Most are found in marine sediments near hydrothermal vents. They are highly motile and show multiple flagella. The thermoplasmatales include Thermoplasma and Picrophilus .