Linking biogeochemical sulfur and iron cycling with the diversity and activity of benthic microbes in coastal Hawaiian marine environments

在夏威夷大学为期两年的博士后研究期间，PI将专注于了解微生物如何影响He‘eia鱼塘中铁和硫的分布。数百年来，鱼塘一直是夏威夷海岸系统的重要组成部分，这项研究将为夏威夷河口微生物介导的化学循环提供见解。研究结果将对夏威夷沿海管理和渔业管理有所帮助。PI还将作为夏威夷大学本科生的导师和榜样，并为Kamehameha学校的学生组织一个科学推广计划。对这一博士后奖学金的投资将促进PI在微生物研究方面的强大背景，这是一个在海洋学中越来越重要的领域。微生物占海洋生物量的90%以上，产生地球上约50%的氧气，并在调节碳、氮、氧、铁、磷和硫等元素的生物地球化学循环中发挥关键作用。然而，我们对海洋中发生的具体生物地球化学过程、这些过程的动力学、相关生物的分类和生理学、群落成员之间复杂的同步营养相互作用以及微生物影响生物活性元素循环的程度的了解有限。Heeia鱼塘是一个受潮汐影响的夏威夷沿海浅水河口系统，光养生物的过度初级生产力和呼吸作用导致溶解氧浓度的显著日变化，并导致沉积物和水柱中氧化还原过渡带的大量垂直迁移。PI将把精细的氧化还原测量和生物能量模拟与分子微生物学和代谢率的直接测量结合在一起，以：(1)限制鱼塘内化学营养能量代谢的范围和分布，(2)计算微生物对铁和硫的形态和分布的影响，以及(3)表征鱼塘内定期发生的底栖生物群落的多样性和分布。

During this two year Postdoctoral Fellowship at the University of Hawaii, the PI will focus her research on understanding how microbes impact the distribution of iron and sulfur in the He'eia Fish Pond. Fish ponds have been an important part of the Hawaiian coastal system for hundreds of years, and this research will provide insights into microbial-mediated chemical cycles in Hawaiian estuaries. The results will be useful for Hawaiian coastal management and fisheries management. The PI will also serve as a mentor and role model for University of Hawaii undergraduates and organize a science outreach program for students at Kamehameha schools. The investment in this Postdoctoral Fellowship will advance the career of the PI who has strong background in microbial research, a field that is of increasing importance in oceanography.Microbes account for more than 90% of biomass in the ocean, produce ~50% of the oxygen on Earth, and play crucial roles in mediating the biogeochemical cycling of elements such as carbon, nitrogen, oxygen, iron, phosphorus and sulfur. However we have a limited understandingof the specific biogeochemical processes that occur within the ocean, the kinetics of these processes, the taxonomy and physiology of the organisms responsible, the complex syntrophic interactions amongst community members, and the extent to which microbes influence the cycling of bioactive elements. Heeia Fishpond is a tidally-influenced, shallow Hawaiian coastal estuarine system where excessive primary productivity and respiration of phototrophic organisms generate striking diel variations in dissolved oxygen concentrations, and lead to substantial vertical migration of redox transition zones in both the sediment and water column. The PI will couple fine-scale redox measurements and bioenergetic modeling with molecular microbiology and direct measurements of metabolic rates to: (1) constrain the extent and distribution of chemotrophic energy metabolisms within the fishpond, (2) calculate the microbial impact on the speciation and distribution of iron and sulfur, and (3) characterize the diversity and distribution of active benthic microbial communities within the fishpond that regularly occur over the diel cycle.