Collaborative Research: Elucidating the roles of biogenic exudates in the cycling and uptake of rare earth elements

细菌催化了许多过程，这些过程对于局部到全球范围内的元素流动至关重要。在许多情况下，这些过程由需要特定金属离子才能发挥作用的酶提供燃料。在过去的十年中，镧和其他稀土元素（REY），长期以来一直被认为在生物学中缺乏作用，已被确定为各种细菌使用的酶的辅因子。这一令人兴奋的发现进一步扩展了生命周期表，并提出了许多关于REY地球化学的问题。该项目的一个核心租户是，由于REY在大多数环境中并不丰富，细菌需要特定的策略来从环境中获取这些元素。该项目将确定和表征与细菌摄取REY相关的分子。由于REY是难以从矿石和废物中纯化的战略材料，因此其结果不仅对理解生物过程很重要，而且可能对经济竞争力和国家安全产生影响。越来越多的人认识到微生物对必需微量金属的吸收是由生物螯合剂介导的。最近的发现，REY是需要PQQ I型醇氧化酶在甲基营养型和其他不同的细菌加上REY的天然存在，在非生物可用的化学形式导致的假设，结构不同，但尚未确定，生物螯合剂（镧系元素）促进溶解和吸收REY从土壤中。该项目将微生物学与协调，土壤和分析化学方法相结合，以识别和表征镧系元素，细菌配体，促进溶解和结合的REY从土壤和其他基质。该项目的结果有可能改变我们对REY在生物系统中的重要性及其对营养循环的影响的看法，并修改当前对营养吸收以及微生物和矿物基质之间关系的思考。该奖项反映了NSF的法定使命，并被认为值得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来支持。

Bacteria catalyze numerous processes that are critical for the flow of elements at local to global scales. In many cases, these processes are fueled by enzymes that require specific metal ions to function. In the last decade, lanthanum and other rare earth elements (REYs), which have long been thought to lack a role in biology, have been identified as cofactors for enzymes used by diverse bacteria. This exciting discovery further expands the periodic table of life and raises many questions about the biogeochemistry of REYs. A central tenant of the project is that, because REYs are not abundant in most environments, bacteria require specific strategies to acquire these elements from their environments. This project will identify and characterize molecules associated with bacterial uptake of REYs. Because REYs are strategic materials that are difficult to purify from ores and waste products, the results are not only important for understanding biological process but also may have implications for economic competitiveness and national security. There is a growing recognition that the microbial uptake of essential trace metals is mediated by biogenic chelating agents. The recent discovery that REYs are required for PQQ Type I alcohol-oxidizing enzymes in methylotrophic and other diverse bacteria coupled with the natural presence of REYs in non-biologically available chemical forms lead to the hypothesis that structurally distinct, but as-yet unidentified, biogenic chelating agents (lanthanophores) facilitate the solubilization and uptake of REYs from soils. This project combines microbiology with coordination, soil, and analytical chemical approaches to identify and characterize lanthanophores, bacteriogenic ligands that promote solubilization and binding of REYs from soils and other matrices. The result of this project have the potential to transform our view of the importance of REYs in biological systems and their impact on nutrient cycling and revise current thinking towards nutrient uptake and the relationships between microorganisms and mineral matrices.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.