How Ingested Soil Microbes Stimulate Greenhouse Gas Emissions and Iron Transformations of Earthworms

高达约50%的土壤排放的一氧化二氮（N2O）可能来自蚯蚓，蚯蚓是一种以土壤微生物群落为食的土壤大型动物。在之前的资助期内，蚯蚓摄入的反硝化剂与N2O和二氮（N2）的排放之间建立了协同联系。新的目标（抽象形式）是：确定蚯蚓是否释放一氧化氮（NO）；确定与肠道中C和n转化相关的摄入微生物群落结构和功能变化相关的调节参数（分子、微传感器和报告菌株技术；pcr辅助分离目标生物）；将蚯蚓丰度与田间N2O和NO排放联系起来；确定蚯蚓生态类型是否会影响粪便和与洞穴相关的土壤（蚓土室、微传感器）中硝酸盐、N2O和O2的原位梯度；评估来自南半球和北半球的蠕虫的N2O排放，并评估与这些排放相关的微生物（功能基因指纹）。这项研究将解决C和n驱动的微生物过程之间的主要联系，这些过程在蚯蚓肠道中产生氮气。

Up to approximately 50% of soil-emitted nitrous oxide (N2O) might be derived from earthworms, a soil macrofauna that ingests soil microbial biomes. In the previous funding period, synergistic links were established between ingested denitrifiers and the emission of N2O and dinitrogen (N2) by earthworms. The new objectives (in abstracted form) are: to determine if earthworms emit nitric oxide (NO); to identify regulatory parameters responsible for changes in the structure and function of ingested microbial biomes associated with C- and N-transformations in the gut (molecular, microsensor, and reporter strain technologies; PCR-assisted isolation of target organisms); to correlate earthworm abundances with N2O and NO emissions in the field; to determine if earthworm ecotypes affect in situ gradients of nitrate, N2O, and O2 in casts and burrow-associated soils (wormsoil chambers, microsensors); to assess N2O emissions of worms from southern and northern hemispheres, and evaluate the microbes associated with these emissions (functional gene fingerprinting). This study will resolve primary links between C- and N-driven microbial processes that yield nitrogenous gases in the earthworm gut.