Collaborative Research: Lake Matano, Indonesia: A modern observatory of ancient ocean biogeochemistry

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。太古宙和元古代海洋在现代水生环境中没有已知的类似物，它们的生物地球化学和微生物学仍然是个谜。马塔诺湖的物理结构、丰富的铁和缺乏的硫酸盐反映了这些早期海洋中普遍存在的分层含铁条件。初步结果表明无氧光养铁生物的增殖，并支持这些生物对早期海洋初级生产的重要性。马塔诺湖活跃的甲烷循环表明，甲烷生成和甲烷转化也可能是地球的重要组成部分。早期的海洋C旋回。甲烷循环通过以Fe（III）为电子受体的甲烷厌氧氧化而与铁循环耦合，这是一种新的生物地球化学途径。考虑到Matano湖的深水可能是缺氧、含铁和缺乏有机物的早期水体的最佳现代模拟物，研究人员寻求进一步阐明这些过程的程度、机制和微生物群落。该项目的具体目标是：1)通过实地和实验室测量，生成马塔诺湖深水和沉积物中铁、甲烷和有机碳的高分辨率地球化学剖面；2)利用直接测量和模拟表征水柱分层、水动力学和物理物质输运速率；3)研究了湖泊微生物群落的结构特征和生物地球化学反应，研究了纯培养和混合培养下的微生物代谢；4)利用反应-输运模型模拟湖泊中铁、碳和甲烷的生物地球化学循环，并计算原位反应速率。这些来自印度尼西亚马塔诺湖的结果将使人们第一次了解在稳定的含铁水生环境中可以发展的微生物生态系统。他们可以证实两种新的生物地球化学途径的发现。更广泛的影响：系统发育数据将现存的生物体放入一个进化框架中。生成的反应输运模型将可应用于其他热带分层湖泊的生物地球化学过程。这些模型和生态学数据将有助于研究古环境中的生物地球化学过程。物理数据将有助于理解弱分层深湖和海洋环境中的混合。此外，一个新颖的国际化教育计划将把来自美国和印度尼西亚的教师和学生聚集在一起，在实地和实验室。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).Archean and Proterozoic oceans have no known analogues in modern aquatic environments, and their biogeochemistry and microbiology remain enigmatic. Lake Matano's physical structure, abundance of Fe and dearth of sulfate mirror the stratified ferruginous conditions thought to prevail in these early oceans. Preliminary results indicate proliferation of anoxygenic photoferrotrophs, and support the significance of these organisms for the primary production in the early ocean. The active methane cycle in Lake Matano demonstrates that methanogenesis and methanotrophy could have also been important components of the Earth?s early marine C cycle. The methane cycle appears coupled to the iron cycle through anaerobic oxidation of methane with Fe(III) as an electron acceptor, a novel biogeochemical pathway. Given that the deep waters of Lake Matano may be the best available modern analogue for the anoxic, ferrugenous, and organic-poor early waters, investigators seek to further elucidate the extent, mechanisms and the microbial communities responsible for these processes. The specific objectives of this project are: 1) to generate high resolution profiles of the geochemistry of iron, methane, and organic carbon in the deep waters and sediments of Lake Matano using field and laboratory measurements; 2) to characterize the water column stratification, hydrodynamics, and the rates of physical substance transport using direct measurements and modeling; 3) characterize the community structure and biogeochemical reactions associated with the microbial communities in the lake and investigate their metabolisms in pure and mixed cultures; 4) simulate the biogeochemical cycling of iron, carbon, and methane in the lake using reaction-transport models and calculate the in-situ reaction rates. These results from Lake Matano, Indonesia, will provide the first glimpse at the microbial ecosystems that can develop in a stable, ferruginous aquatic environment. They can confirm the discoveries of two novel biogeochemical pathways. Broader Impacts: Phylogenetic data will place extant organisms into an evolutionary framework. Generated reactive transport models will be transferable to biogeochemical processes in other tropical stratified lakes. These models and ecology data will help examine biogeochemical processes in paleo-environments. Physical data will help understand mixing in weakly stratified deep lacustrine and marine environments. Additionally, a novel internationalized educational plan will bring faculty and students from the USA and Indonesia together in the field and in the laboratory.