In:
Canadian Journal of Zoology, Canadian Science Publishing, Vol. 75, No. 10 ( 1997-10-01), p. 1618-1627
Abstract:
Two commonly used methods for in vitro measurement of tissue-level sulfide oxidation in animals were compared using homogenates of hydrothermal vent (Paralvinella sulfincola and P. palmiformis) and non-vent (Nereis virens and Nephtys caeca) polychaetes. All examined worms showed heat-labile sulfide-oxidizing ability and rates were slightly higher in the two vent species. A previously observed discrepancy between the results of the spectrophotometric benzyl viologen (BV) and bimane high-performance liquid chromatography (HPLC) assays was confirmed. We explain this discrepancy firstly by the fact that H 2 S removal measured by the bimane HPLC assay is only the first step in a cascade of several possible sulfur-oxidation steps recorded by BV. Secondly, we show that the low H 2 S/protein ratio used in the bimane HPLC assay can result in undersaturation of the catalyst responsible for H 2 S oxidation. The latter can lead to underestimation of potential oxidation rates and may be as important as the nonspecificity of BV in explaining differences between assay results. Tissue-level sulfide oxidation is clearly widespread in marine invertebrates, but the catalyst(s) responsible remain(s) unidentified. The fact that sulfide-oxidation rates in vent polychaete tissues are similar to rates in non-vent species and appear to reflect a common basal level of sulfide-oxidizing activity in many animal tissues suggests that other defense mechanisms may be more important in the adaptation of these worms to the hydrothermal milieu.
Type of Medium:
Online Resource
ISSN:
0008-4301
,
1480-3283
Language:
English
Publisher:
Canadian Science Publishing
Publication Date:
1997
detail.hit.zdb_id:
1490831-1
SSG:
12
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