The hydrocarbon seep tubeworm Lamellibrachia luymesi primarily eliminates sulfate and hydrogen ions across its roots to conserve energy and ensure sulfide supply
The hydrocarbon seep tubeworm Lamellibrachia luymesi primarily eliminates sulfate and hydrogen ions across its roots to conserve energy and ensure sulfide supply
复制标题
DOI：
10.1242/jeb.02413
复制
发表时间：
2006-10-01
影响因子：
2.8
通讯作者：
Fisher, Charles R.
中科院分区：
文献类型：
--
作者：
Dattagupta, Sharmishtha;Miles, Lara L.;Fisher, Charles R.
Lamellibrachia luymesi（多毛类，Siboglinidae）是一种深海vestimentiferan管虫，在墨西哥湾的碳氢化合物渗漏处形成大的类水母聚集体。像所有的vestimentiferans，L。luymesi从硫化物氧化内共生细菌中获得营养，这些细菌被安置在称为营养体的内部器官中。这种管虫的寿命超过170年，它的生存取决于在这一漫长时期内硫化物的可用性。在L.在luymesi聚集体中，微生物通过硫酸盐还原与烃氧化耦合产生硫化物。L. luymesi利用其埋藏在沉积物中的根状后部延伸体从沉积物中获取硫化物。其共生体然后氧化硫化物以产生用于碳固定的能量，并释放硫酸根和氢离子作为副产品。对于管虫来说，消除这些废物离子是至关重要的，它可以通过其血管羽或通过其根部来消除这些废物离子。在这项研究中，我们测量了硫酸盐和质子消除率从活L。luymesi的研究发现，它们消除了约85%的硫化物氧化产生的硫酸盐，以及约67%的各种代谢过程产生的质子。在使用膜转运抑制剂的实验的基础上，我们建议L。Luymesi具有阴离子交换剂，该阴离子交换剂介导硫酸盐消除和碳酸氢盐吸收。根可能是理想的交换表面，消除硫酸根和氢离子有两个原因。首先，这些离子可以通过促进扩散穿过根上皮被消除，这在能量上是经济的。其次，硫酸盐和氢离子是细菌硫酸盐还原的底物，将这些离子供应到沉积物中可能有助于确保L.在其整个生命周期中。
Lamellibrachia luymesi ( Polychaeta, Siboglinidae) is a deep-sea vestimentiferan tubeworm that forms large bushlike aggregations at hydrocarbon seeps in the Gulf of Mexico. Like all vestimentiferans, L. luymesi obtains its nutrition from sulfide-oxidizing endosymbiotic bacteria, which it houses in an internal organ called the trophosome. This tubeworm has a lifespan of over 170 years and its survival is contingent upon the availability of sulfide during this long period. In sediments underlying L. luymesi aggregations, microbes produce sulfide by coupling sulfate reduction with hydrocarbon oxidation. L. luymesi acquires sulfide from the sediment using a rootlike posterior extension of its body that is buried in the sediment. Its symbionts then oxidize the sulfide to produce energy for carbon fixation, and release sulfate and hydrogen ions as byproducts. It is critical for the tubeworm to eliminate these waste ions, and it could do so either across its vascular plume or across its root. In this study, we measured sulfate and proton elimination rates from live L. luymesi and found that they eliminated approximately 85% of the sulfate produced by sulfide oxidation, and approximately 67% of the protons produced by various metabolic processes, across their roots. On the basis of experiments using membrane transport inhibitors, we suggest that L. luymesi has anion exchangers that mediate sulfate elimination coupled with bicarbonate uptake. Roots could be the ideal exchange surface for eliminating sulfate and hydrogen ions for two reasons. First, these ions might be eliminated across the root epithelium using facilitated diffusion, which is energetically economical. Second, sulfate and hydrogen ions are substrates for bacterial sulfate reduction, and supplying these ions into the sediment might help ensure a sustained sulfide supply for L. luymesi over its entire lifespan.