Excellence in Research: Metaomics-based characterization of the mutually beneficial interkingdom “cross-talk” between algae and bacteria- it takes two to tango

藻类通常被认为是环境中的有害生物，因为某些物种会引起有害的藻华和/或赤潮，导致海滩关闭，扰乱休闲和钓鱼活动。然而，一些藻类物种，当在特定条件下生长时，可以解决一个重大的全球社会问题；也就是说，一些藻类物种可以帮助清洁人类产生的废水。最近对一种新分离的微藻（Scenedesmus sp. strain AC-2）和细菌菌株（Pseudomonas sp. strain AC-1）的研究表明，这两种生物形成了互利的伙伴关系，从而加快了废水的清理速度。该项目的目标是更好地了解细菌-藻类的共生伙伴关系，并利用这些信息来加强对大量废水的清理。该项目还将为少数民族学生提供创新研究和指导机会。现在越来越多的文献将藻类称为自然界的绿色黄金，因为藻类细胞具有无与伦比的能力，可以生产各种各样的生物基增值产品，如生物燃料（生物柴油、生物电、生物甲烷和喷气燃料）、营养药品/药品（类胡萝卜素、ß-胡萝卜素、omega - 3多不饱和不饱和脂肪（PUFA）和虾青素）和其他产品（化妆品、生物塑料、淀粉、蛋白质、油和肥料）。迄今为止进行的大多数研究都依赖于使用单一的微藻菌株来获得生物制品，但最近的研究结果表明，细菌物种（假单胞菌sp.菌株AC-1）和微藻（Scenedesmus sp.菌株AC-2）之间的共生关系可以显著增强对未处理废水的修复，同时提高藻类原油和潜在的其他增值产品的产量。因此，该项目的首要假设是共生细菌和藻类细胞的联盟，当它们一起生长时，将产生互利的积极影响，例如更快的生长和更高的生物基产品产量。相反，分离的藻类和细菌在分开生长时，将破坏互利的共生过程，并表现为失去积极影响（例如，废水养分消耗和原油产量）。为了解决这一总体假设，该项目将做以下工作：1)利用创新实验评估新分离的细菌-藻类共生体之间的界间“交叉对话”，这些实验依赖于同位素标记的细胞来追踪与互利影响相关的细胞蛋白质组和代谢组的变化；2)利用定制的共培养装置，实验验证细菌与藻类之间的共生网络；3)应用生物信息学和统计分析表征通路之间的“串扰”；4)利用上述前沿研究培养下一代少数民族学生。该项目将大大加强研究和学生培训活动，并以创新研究为基础的教育和培训STEM学科中代表性不足的学生的良好记录为基础。拟议的工作将对接和利用正在进行的国家科学基金会和其他资助项目，如noaa资助的海岸和海洋生态系统中心（CCME）；这些项目继续提供创新的研究型教学法和学生培训，特别是对代表性不足的非洲裔美国少数民族学生。全面而深入地了解细菌-藻类关联的分子基础和互利的积极影响，将为刺激以藻类为基础的绿色经济和促进社会可持续发展目标提供变革性的发现。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。

Algae are typically considered nuisance organisms in the environment because some species can cause harmful algal blooms and/or red tides leading to beach closures and disruption of leisurely and fishing activities. However, some algal species, when grown under specific conditions, can solve a major global societal problem; namely, some algal species can aid in the cleaning of human-generated wastewater. Recent research using a newly isolated microalgae (Scenedesmus sp. strain AC-2) and bacterial strain (Pseudomonas sp. strain AC-1) has shown that the organisms form mutually beneficial partnerships resulting in faster clean-up of wastewater. The goal of this project is to better understand bacterial-algal symbiotic partnerships and to use this information to enhance the clean up of larger amounts of wastewater. This project will also offer minority students innovative research and mentoring opportunities. A growing body of literature now refers algae as nature’s green gold because algal cells possess an unparallel ability to produce a wide variety of bio-based value-added products, such as biofuels (biodiesel, bioelectricity, biomethane and jet fuels), nutraceuticals/ pharmaceuticals (carotenoids, ß-Carotene, omega 3 polyunsaturated unsaturated fats (PUFA) and astaxanthin) and other products (cosmetics, bioplastics, starches proteins, oils and fertilizers). Most studies conducted to date have relied on the use of a single microalgal strain to obtain bioproducts, but recent findings indicate that symbiotic associations between bacterial species (Pseudomonas sp. strain AC-1) and microalgae (Scenedesmus sp. strain AC-2) can significantly enhance remediation of untreated wastewater concurrent to higher production of algal crude oil and potentially other value-added products. Therefore, the overarching hypothesis of this project is that a consortium of symbiotic bacteria and algal cells, when grown together, will result in mutually beneficial positive impacts, such as faster growth and higher yields of bio-based products. Conversely, algal and bacterial isolates, when grown separately, will disrupt the mutually beneficial symbiotic processes and manifest in a loss of positive impacts (e.g., wastewater nutrient depletion and crude oil yields). To address the overarching hypothesis, this project will do the following: 1) evaluate the interkingdom “cross-talk” between the newly isolated bacterial-algal symbionts using innovative experiments that rely on isotopically-labelled cells to trace shifts in cellular proteomes and metabolomes that correlate to mutually beneficial impacts; 2) utilize customized co-culture devices to experimentally validate the symbiotic networks identified between bacteria and algae; 3) apply bioinformatics and statistical analyses to characterize “cross-talk” between pathways; 4) train the next generation of minority students using the above cutting-edge research. This project will significantly enhance research and student training activities, and build upon the proven track record of innovative research-based education and training of underrepresented students in STEM disciplines. The proposed work will interface and leverage from ongoing NSF and other funded projects such as the NOAA-funded Center for Coastal and Marine Ecosystems (CCME); these projects continue to provide innovative research-based pedagogy and student training, particularly to underrepresented African American minority students. Obtaining a comprehensive and deeper understanding of the molecular underpinnings of bacterial-algal associations and mutually beneficial positive impacts will provide transformative findings for stimulating the algal-based green economy and advance sustainable developmental goals for society.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.