Bioavailability of Carbon and Iron from Viral Lysis Products

研究人员将研究病毒在海洋系统中铁（Fe）和碳(C)的生物地球化学循环中的作用。病毒是原核生物死亡的主要原因，但尽管许多人认为它们在营养物质循环中很重要，但对这一过程的定量评估却很少。初步数据表明，病毒可以介导元素向细菌和其他浮游生物的快速转移。由于原核生物代表了海洋中大部分的生物生物量，自养和异养原核生物的病毒裂解代表了对海洋生物潜在限制营养物质的研究很少。最近的证据还表明，铁对海洋生物的生物利用度受海水中未表征的有机配体对铁的络合作用的调节。该项目将使用放射性同位素和超滤技术直接测量病毒介导的铁和C从宿主细胞释放，并检查随后的铁生物利用度。在亚热带大西洋和乔治亚海峡（不列颠哥伦比亚省）进行的实地研究将通过侧重于大小分级的病毒-宿主群落动态和铁/碳转移来补充实验室研究。

The investigator will examine the role of viruses in the biogeochemical cycling of iron (Fe) and carbon (C) in marine systems. Viruses are a major cause of prokaryotic mortality, but in spite of many suggestions that they are important in nutrient recycling, only minimal quantitative evaluations of this process exist. Preliminary data demonstrate that viruses can mediate rapid transfers of elements to bacteria and other plankton. As prokaryotic organisms represent the majority of the living biomass in the ocean, viral lysis of autotrophic and heterotrophic prokaryotes represents a little studied source of potentially limiting nutrients to marine organisms. Recent evidence also suggests that the bioavailability of Fe to marine organisms is regulated by the complexation of Fe by uncharacterized organic ligands in seawater. This project will directly measure virus-mediated release of Fe and C from host cells using radioisotope and ultrafiltration techniques, and examine subsequent Fe bioavailability. Field studies in the subtropical Atlantic Ocean and Strait of Georgia (British Columbia) will complement the lab studies by focussing on size-fractionated virus-host community dynamics and Fe/C transfer.