. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. J. B. WITTENBERG AND J. L. STEIN the oxygen pressure is held low (18). This is in accord with the suggestion that low oxygen pressure is probably required to allow RuBisCO to maintain net carboxylation in the Alviniconcha gill (7). The concentration of hydrogen sultide likewise is probably low, perhaps in the nanomolar range (8), and the concentration of free hydrogen sulfide may not be sufficient to support the flux of hydrogen sul- fide to the symbiont. A specimen of the Western Pacific hydrothermal vent gastropod Alvinico
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. J. B. WITTENBERG AND J. L. STEIN the oxygen pressure is held low (18). This is in accord with the suggestion that low oxygen pressure is probably required to allow RuBisCO to maintain net carboxylation in the Alviniconcha gill (7). The concentration of hydrogen sultide likewise is probably low, perhaps in the nanomolar range (8), and the concentration of free hydrogen sulfide may not be sufficient to support the flux of hydrogen sul- fide to the symbiont. A specimen of the Western Pacific hydrothermal vent gastropod Alviniconcha hessleri was collected by the sub- mersible Alvin at the "Snail Pit" site (18° ' N, 144° ' E. about 3650m depth) on Dive number 1837. 23 April 1987. The gill, g wet weight, was stored frozen in liquid nitrogen and a clear soluble extract pre- pared in ml of buffer (19). Optical direct spectra of this extract display a prominent narrow feature at 551 nm. This unchanging feature ascribed to reduced soluble sym- o • CD tr 8 CD. 500 550 600 WAVELENGTH, nm 650 Figure 1. Optical difference spectra of the extract of Alviniconcha gill. Features ascribable to oxyhemoglobin were inconspicuous in the direct spectrum of the extract, suggesting that some component of the solution had consumed the dissolved oxygen. Accordingly the solution was equilibrated with oxygen gas. The difference spectrum of the oxy- genated solution minus that of the initial (deoxygenuted) solution (spec- trum not shown) exhibits conspicuous features at 541 and 579 nm. di- agnostic of oxygenated hemoglobin. A small feature near 622 nm sug- gested the presence of feme hemoglobin. This feature increased in magnitude with time. The difference spectrum in the Soret region (spec- trum not shown) of a portion of the sample that had been stored for 60 mm at ice temperature minus that of a portion of the solution to which sodium dithiomte (a reagent that removes oxygen and reduces most
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
