Collaborative Research: Ammonia oxidizers and their heterotrophic friends

合作研究：氨氧化剂及其异养朋友

• 批准号: 1755270
• 负责人: Annette Bollmann
• 金额: $ 36.81万
• 依托单位: Miami University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1755270&HistoricalAwards=false
• 关键词: Collaborative; Research; Ammonia; oxidizers; their

Microorganisms play a major role in the global nitrogen cycle. One group of bacteria, ammonia oxidizing bacteria, oxidize ammonium to nitrite and thus play a key role in the removal of ammonium from human derived urea in wastewater treatment plants. In nature, diverse microorganisms coexist and interact in complex ways. Communities of different microorganisms can perform vital functions more efficiently than single species achieve alone. Ammonia oxidizing bacteria are one example, where ammonia is converted more efficiently when in a microbial community than when the oxidizing bacteria are alone. Yet, the interactions among microbial neighbors that improve ammonia conversion are not well understood. The goal of this project is to better understand how living in microbial communities improves ammonia oxidizing bacteria's ability to convert ammonia. An additional goal of this project is to educate a diverse group of students on the importance of microbial communities, and to raise awareness and urgency about water quality. Graduate and undergraduate students will be trained in state of the art microbiology techniques and involved in the research. Elementary school students from rural Ohio and undergraduate non-microbiology majors will be taught about the importance of microbial communities, nitrification, and water quality. This research will provide important insight into synergistic interactions within bacterial communities and increase the ability to manipulate microbial communities for improved or desired function, such as those in wastewater plants to improve ammonia removal.Ammonia-oxidizing bacteria (AOB) oxidize ammonia to nitrite. AOB are core contributors to nitrification, a crucial step in the global nitrogen cycle. As part of microbial communities, AOB positively interact with nitrite-oxidizing bacteria and heterotrophic bacteria. It has already been shown that the nitrite-oxidizing bacteria keep the level of toxic nitrite around AOB low, maintaining a beneficial environment that allows for AOB growth. The mechanisms underlying the positive interactions of AOB with heterotrophic bacteria have not been elucidated. These positive interactions will be investigated in well-defined laboratory co-cultures, enrichment cultures, and native environments. Experiments will include (1) proteome and transcriptome analysis of the AOB Nitrosomonas sp. Is79 in the presence of heterotrophic bacteria as single and mixed cultures; (2) proteome analysis of three additional AOB strains in the presence of heterotrophic bacteria; and (3) proteome analysis of an AOB incubated in their original environment. The results will be analyzed to identify strain-specific physiological responses in order to determine the nature of the interactions between AOB and heterotrophic bacteria. Insights into the molecular mechanisms and metabolic pathways in AOB that are impacted by heterotrophic bacteria will add to the growing field of research on autotrophic-heterotrophic interactions. This research will also address the physiological similarities and differences in AOB grown in laboratory pure cultures, in laboratory enrichment cultures, and in their original 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.

微生物在全球氮循环中发挥着重要作用。一组细菌，氨氧化细菌，将铵氧化为亚硝酸盐，因此在废水处理厂中从人源尿素中去除铵中起关键作用。在自然界中，多种微生物共存，并以复杂的方式相互作用。不同微生物的群落可以比单个物种单独实现更有效地执行重要功能。氨氧化细菌是一个例子，其中氨在微生物群落中比氧化细菌单独存在时更有效地转化。然而，提高氨转化的微生物邻居之间的相互作用还没有得到很好的理解。该项目的目标是更好地了解生活在微生物群落中如何提高氨氧化细菌转化氨的能力。该项目的另一个目标是教育不同群体的学生了解微生物群落的重要性，并提高对水质的认识和紧迫性。研究生和本科生将接受最先进的微生物学技术培训，并参与研究。来自俄亥俄州农村的小学生和非微生物学专业的本科生将学习微生物群落、硝化作用和水质的重要性。这项研究将为了解细菌群落之间的协同作用提供重要的见解，并提高操纵微生物群落以改善或实现所需功能的能力，例如在污水处理厂中提高氨的去除率。AOB是硝化作用的核心贡献者，硝化作用是全球氮循环的关键步骤。作为微生物群落的一部分，氨氧化细菌与亚硝酸盐氧化细菌和异养细菌之间存在正相互作用。已经表明，亚硝酸盐氧化细菌使AOB周围的有毒亚硝酸盐水平保持在较低水平，从而维持了允许AOB生长的有利环境。AOB与异养细菌的正相互作用的机制尚未阐明。将在明确定义的实验室共培养物、增菌培养物和天然环境中研究这些积极的相互作用。实验将包括（1）在异养细菌存在下，作为单一和混合培养物的AOB亚硝化单胞菌Is 79的蛋白质组和转录组分析;（2）在异养细菌存在下，另外三种AOB菌株的蛋白质组分析;以及（3）在其原始环境中孵育的AOB的蛋白质组分析。将对结果进行分析，以确定菌株特异性生理反应，从而确定AOB和异养细菌之间相互作用的性质。深入了解AOB中受异养细菌影响的分子机制和代谢途径将增加对自养-异养相互作用的研究领域。这项研究也将解决生理上的相似性和差异AOB生长在实验室纯培养，在实验室富集培养，并在其原始environments.This奖项反映了NSF的法定使命，并已被认为是值得的支持，通过评估使用基金会的智力价值和更广泛的影响审查标准。