Securing reactive nitrogen for high value food and feed production in integrated bioremediation and energy generation systems

氮已被确定为全球粮食不安全的驱动因素之一，因此，适当的氮管理对于养活不断增长的全球人口至关重要，据估计，到2050年，全球人口将达到90亿。在水产养殖和农业生产链的多个层面上，氮素利用效率低下，导致全球氮素循环中的净氮负荷，并威胁到地球在活性氮污染方面的可持续性。目前处理富氮废水的技术侧重于将活性氮转化为惰性氮，即大气中的氮气。然而，氮的价值太高而不能丢失，与其寻求推广永久去除氮的技术，还需要新的、创新的方法，专注于回收有价值的资源，以开创可持续的粮食生产系统，并催化氮循环的新革命。这项研究将开发混合废物处理、蛋白质生产和能源产生系统，以处理陆地集约化农业和水产养殖系统中富含氮的废物。这些创新系统旨在通过将氮转化为高价值蛋白质，以海参、蚯蚓和海洋蠕虫等具有商业价值的沉积物喂食者的形式，重新利用和回收氮。这些生物被收获并加工成人类食物和家畜饲料的替代饲料成分。沉积物喂食者与土壤和沉积物及其肠道中自然存在的微生物群落协同工作，分解废物并将其转化为高价值蛋白质。添加碳以平衡营养，排除氧气以促进氮的吸收和并入细胞，在细胞中氮可以被向上循环为海参和蠕虫形式的高价值生物质。分解废物的微生物产生的能量被用作可持续的电力来源，而碳源和沉积物喂养无脊椎动物的增加将提高系统的整体能源产生潜力。我们高度可持续的方法通过配对来自农业的富碳废水来向上循环和修复来自水产养殖的富氮废水，最重要的是，防止系统中的氮损失。这一方法使当前的优先事项保持一致，以促进养分循环，并鼓励在两个第一产业中增加废物流的价值。我们的方法是革命性的，因为我们关闭了氮循环，通过这样做，我们取代了寻求通过将氮转化回大气来永久去除氮的传统废水处理技术。这位研究员将用出色的科学来展示如何巧妙地组合和操纵简单的生物体和废物资源，以设计出低成本的系统，为当前农产工业部门面临的全球挑战提供无数解决方案。这一独特的方法正面解决了迅速发展的“粮食安全--贫困--污染”之间的关系，并为最终结束“氮循环”提供了一个独特的机会。此外，这些系统被设计为可扩展、可转移和可适应一系列不同的环境和行业。在研究金期间，这些系统将在热带(毛里求斯)和温带(英国)环境、海洋(水产养殖)和陆地(农业)环境中开发，技术转让和吸取的经验教训将为系统设计提供信息和优化。我们的低技术系统提供了一种简单、低成本的选择，可以在英国，特别是在低收入的热带国家，使农产工业部门的生产多样化，增加收入，并减少对环境的影响。此外，这项技术的大规模传播和采用有可能纠正全球氮循环中的失衡，并确保后代粮食和饲料生产系统的安全。

Nitrogen has been identified as one of the drivers of global food insecurity, therefore proper nitrogen management will be critical to feed a growing global population, estimated to reach 9 billion by 2050. Inefficiencies of nitrogen use occur at multiple levels within the aquaculture and agriculture production chain, leading to net nitrogen loading in the global nitrogen cycle and threatening the sustainability of the planet in terms of reactive nitrogen pollution. Current technologies to treat nitrogen-rich effluent focus on converting reactive nitrogen to back to its inert form, as nitrogen gas in the atmosphere. However, nitrogen is too valuable to be lost, rather than looking to promote technologies for permanent removal of nitrogen, novel, innovative approaches are needed that focus on the recovery of valuable resources to pioneer sustainable food production systems and catalyse a new revolution in the nitrogen cycle.This research will develop hybrid waste treatment, protein production and energy generation systems to treat nitrogen rich waste from land-based intensive agriculture and aquaculture systems. These innovative systems are designed to re-use and recycle nitrogen, by converting it into high value protein, in the form of commercially valuable deposit feeders such as sea cucumbers, earthworms and marine worms. These organisms are harvested and processed into human food and alternative feed ingredients for livestock feed. The deposit feeders work in concert with microbial communities naturally present in soils and sediments and their guts, to break down the waste and convert it to high value protein. Carbon is added to balance the nutrients and oxygen is excluded to promote the uptake and incorporation of nitrogen into their cells, where it can be upcycled into high value biomass in the form of sea cucumbers and worms. The energy generated by the microorganisms breaking down the waste is harnessed as a sustainable source of electricity, while the addition of carbon sources and deposit feeding invertebrates will enhance the overall energy generation potential of the system. Our highly sustainable approach upcycles and remediates nitrogen-rich effluent from aquaculture, by pairing carbon-rich waste streams from agriculture, and crucially, preventing nitrogen loss from the system. This approach aligns current priorities to promote nutrient recycling and encourage value-addition of waste streams in both primary industries. Our approach is revolutionary in that we close the nitrogen-loop and by so doing we displace traditional wastewater treatment technologies that seek to permanently remove nitrogen by converting it back to the atmosphere. The research fellow will use excellent science to demonstrate how simple organisms and waste resources, can be cleverly combined and manipulated to engineer low-cost systems, that provide a myriad of solutions to the current global challenges facing the agro-industry sector. This unique approach tackles head-on a burgeoning 'food security-poverty-pollution' nexus and delivers a unique opportunity to finally close the 'nitrogen-loop'. Furthermore, the systems are designed to be scalable, transferable and adaptable to a range of different environments and industries. During the course of the fellowship, the systems will be developed in tropical (Mauritius) and temperate (UK) environments, in marine (aquaculture) and terrestrial (agriculture) environments , with technology transfer and lessons learned informing and optimising system design. Our low-tech system offers a simple, low cost option to diversify production in the agro-industry sector, increase revenue, and reduce environmental impacts in the UK and particularly in lower income tropical countries. Furthermore, the large-scale dissemination and adoption of this technology has the potential to correct imbalances in the global nitrogen cycle and secure food and feed production systems for generations to come.