Collaborative Research: The stoichiometric trait distribution of the marine microbiome

碳、氮和磷的元素比例（C:N:P）一直被认为是海洋环境中的固定比例，但最近的工作已经证明了跨纬度的变化。这种变化可能对海洋生物地球化学和大气二氧化碳水平产生重大影响。因此，未来海洋群落C:N:P的变化可能是全球变化的关键反馈。颗粒有机物（POM）的元素组成代表了各种微生物以及非生物颗粒的总和值。然而，我们目前还不清楚单个细胞和颗粒如何导致POM中C:N:P的变化。该项目正在确定在一系列条件下生长的单个微生物细胞的生物量C:N:P，并从不同的海洋生物群落中取样。由于不同的个体可能有不同的命运（例如下沉，裂解，捕食），了解微生物生物量C:N:P的性状分布如何与细胞大小和营养模式相关，以及环境条件如何影响每种性状分布，为研究海洋C， N和P循环提供了新的视角和见解。本项目支持博士生2名，本科生多名。博士生被整合到每个机构现有的微生物组科学网络中，有机会在不同学科之间进行合作。这两所大学的本科生都是通过针对代表性不足群体的现有培训项目招收的。此外，PI Hall是科罗拉多州立大学生态学家和诗人合作项目的一部分，该项目研究如何将生态关系转化为非传统媒体，使其更容易被公众接受和影响。该小组通过创建书面文本的特征分布和去除个体的不同模式（例如，单词）来探索海洋微生物组中个性的本质，以更好地理解和交流地球上最小的生物（海洋微生物）的个体如何对周围的生态系统（即，地球）产生巨大影响。该项目的成果将被纳入科罗拉多州立大学工作组的未来项目，包括公开演讲、艺术装置和出版材料。本项目旨在通过评估微生物元素化学计量学的个体性，量化环境条件与海洋微生物C:N:P之间的关系。为了实现这一目标，该项目使用能量色散光谱（EDS）来评估不同资源和温度处理下种群和群落的化学计量特征分布，并在广泛的纬度梯度上进行海洋实地工作。研究人员假设，颗粒有机物（POM）的化学计量与环境条件之间的关系被海洋微生物组单个成分的不同反应所掩盖。他们假设，这些不同的反应导致了海洋微生物群中颗粒碳(C)、氮(N)和磷(P)的多模态分布。研究了50个海洋分离菌（自养和异养）在不同资源和温度环境下的3个化学计量性状（生物量C:N、C:P和N:P）分布特征。他们描述了从海洋不同区域取样的海洋群落在相同资源和温度环境下的相同特征分布。他们正在参加一次远洋巡航，以表征海洋微生物组在自然资源和温度梯度中的化学计量特征分布。了解微生物群落的组成成员如何改变其生物量以响应环境变化，为海洋环境变化和不同海洋环境中颗粒C:N:P比率之间的联系提供了缺失的一环。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The elemental ratios of carbon, nitrogen, and phosphorus (C:N:P) have been considered fixed proportions in marine environments but recent work has demonstrated changes across latitudes. Such variation can have large implications for marine biogeochemistry and atmospheric CO_2 levels. As such, future variations in ocean community C:N:P could be a key feedback to global change. The elemental composition of particulate organic matter (POM) represents the aggregate value of diverse microorganisms as well as non-living particles. However, we currently do not understand how individual cells and particles contribute to observed variation in the C:N:P of POM. This project is determining the biomass C:N:P of individual microbial cells grown under a range of conditions and sampled from diverse ocean biomes. Because different individuals are likely to have different fates (e.g., loss to sinking, lysis, predation), understanding how the trait distribution of microbial biomass C:N:P relates to cell size and trophic mode and how environmental conditions affect each trait’s distribution offers new perspectives and insight into marine C, N, and P cycles. This project supports two PhD students and multiple undergraduate students. The PhD students are integrated into existing networks on microbiome science at each institution with opportunities to collaborate across diverse disciplines. Undergraduate students at both institutions are being recruited through existing training programs that target underrepresented groups. In addition, PI Hall is part of a collaborative of Ecologists and Poets at CSU, that look at ways to translate ecological relationships to non-traditional media to make it more accessible and impactful to the general public. This group is exploring the nature of individuality within the marine microbiome by creating trait distributions of written text and removing different modes of individuals (e.g., words) to better understand and communicate how individuals from the smallest organisms on the planet (marine microorganisms) can have large effects on the surrounding ecosystem (i.e., the planet). Results from this project are being incorporated into future projects of the working group at Colorado State University including public presentations, art installations, and published materials. The aim of this project is to quantify the relationship between environmental conditions and marine microbial C:N:P by assessing the individuality in microbial elemental stoichiometry. To achieve this the project uses energy dispersive spectroscopy (EDS) to assess the stoichiometric trait distribution of populations and communities under different resource and temperature treatments and oceanographic field work across a broad latitudinal gradient. The researchers hypothesize that the relationship between the stoichiometry of particulate organic matter (POM) and environmental conditions are masked by distinct responses of individual constituents of the marine microbiome. They hypothesize that these distinct responses result in a multi-modal distribution of particulate carbon (C), nitrogen (N), and phosphorus (P) of the marine microbiome. The investigators are characterizing the distribution of three stoichiometric traits (biomass C:N, C:P, and N:P) for 50 marine isolates (both autotrophs and heterotrophs) under different resource and temperature environments. They are characterizing the same trait distribution for marine communities sampled from different regions of the ocean for the same resource and temperature environments as the population experiments. They are participating on an ocean going cruise to characterize stoichiometric trait distribution of the marine microbiome across natural gradients of resources and temperature. Understanding how constituent members of microbial communities alter their biomass in response to environmental change is providing a missing link between the variation in the ocean’s environment and particulate C:N:P ratios for diverse marine environments.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.