Walther Stoeckenius

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The purple membrane of Halobacterium halobium contains only one protein, bacteriorhodopsin, which closely resembles the visual pigments of animals. Light flashes cause a rapid transient shift of its absorption maximum from 560 to 415 nm. This shift is accompanied by release and uptake of protons. Respiring cells acidify the medium in the dark; if they(More)
The action spectrum and quantum efficiency (phi H+) for proton ejection from Halobacterium halobium have been determined under conditions chosen to minimize light-triggered proton influx which is usually observed in intact cells. The action spectrum for the carotenoid-containing strain, R1, shows that light energy absorbed by the carotenoids does not(More)
Three morphologically similar strains of halophilic, box-shaped procaryotes have been isolated from brines collected in the Sinai, Baja California (Mexico), and southern California (United States). Although the isolates in their morphology resemble Walsby's square bacteria, which are a dominant morphological type in the Red Sea and Baja California brines,(More)
The "square" bacterium, first described by Walsby from brine collected at the Red Sea shore [A. E. Walsby, Nature (London) 283:69-71, 1980] was examined by electron microscopy. The cells appeared as flat rectangular boxes in scanning electron micrographs. In sections and freeze-fracture preparation, the edges looked more rounded. The thickness apparently(More)
On the basis of data obtained by spectroscopic analysis and chromatography of retinal extracts, a consensus has been adopted that dark-adapted purple membrane (pm) contains 13-cis- and all-trans-retinal in equal amounts, whereas the light-adapted membrane contains all-trans-retinal only. We have developed an improved extraction technique which extracts up(More)