Dissertation Research: Decoding the dynamics of cryptic microscale biogeochemical cycling in a phototropic consortium

微生物代谢自早期地质时代起就塑造了全球生态系统，尽管出现了宏观生命，但仍是推动全球营养循环的引擎。在不同的环境中，从深海到人类肠道，这些基本的生态系统过程不是由单一物种调节的，而是由新陈代谢相互依赖的微生物群落相互作用所调节的。生态系统的健康依赖于这些错综复杂的相互作用的微生物网络。然而，这种交换通常是通过传统方法看不见的，涉及的化学转换仍然是神秘的。这项建议研究了微生物聚集体，即西佩维塞特盐沼的“粉红色浆果”，作为一个模型系统，以了解微生物相互作用如何在与微生物相关的空间尺度(纳米到微米)上调节营养循环。这项研究将把一天中碳循环的波动与微米级硫循环的变化联系起来。这项工作调查了硫化物氧化光合细菌的碳转移如何驱动附近硫酸盐还原细菌的代谢活动。将使用一种跨学科的方法来合成来自高通量基因组学和系统生物学的信息和来自高分辨率地球化学分析技术的数据。这项拟议的研究将开创新的方法，阐明微生物相互作用对生态系统内物质和能量流动的影响，这将广泛适用于其他生态系统。这项工作不仅与理解微生物相互作用有关，而且将为模拟现代和早期地球历史中的硫循环提供必要的基准。对该项目的支持将加强全国四大研究机构之间的研究合作，并促进从毕业生到K-12级别的教育机会。所有数据都将向公众开放，研究成果将通过公共讲座和科学博客广泛传播。

Microbial metabolism has shaped the global ecosystem since early geological time and, despite the emergence of macroscopic life, remains the engine that drives global cycling of nutrients. In diverse environments, from the deep sea to the human gut, these essential ecosystem processes are mediated not by a single species, but by the interactions of metabolically-interdependent microbial communities. Ecosystem health depends upon these intricate webs of interacting microbes. However, such exchanges are often invisible via traditional approaches, and the chemical transformations involved remain cryptic. This proposal investigates microbial aggregates, the 'pink berries' of the Sippewissett salt marsh, as a model system for understanding how microbial interactions moderate nutrient cycles over spatial scales relevant to microorganisms (nanometers to micrometers). This research will link fluctuations in carbon cycling throughout the day with changes in the micrometer-scale sulfur cycle. This work investigates how the transfer of carbon from sulfide-oxidizing photosynthetic bacteria drives the metabolic activity of nearby sulfate reducing bacteria. An interdisciplinary approach will be used to synthesize information from high-throughput genomics and systems biology with data from high-resolution geochemical analytical techniques. The proposed research will pioneer new ways to elucidate the influence of microbial interactions on material and energy flux within ecosystems that will be broadly applicable across other ecosystems. This work is relevant not only to understanding microbial interactions, but will provide needed benchmarks for modeling of the sulfur cycle in both modern and early earth history. Support for this project will strengthen research collaborations between four major research institutions across the country, and foster educational opportunities from the graduate through K-12 level. All data will be publicly accessible and research findings will be communicated broadly, through public lectures and science blogs.