In the quest for sustainable alternatives to energy-intensive industrial processes, a team of researchers led by Meiwei Guo from the Key Laboratory of Industrial Ecology and Environmental Engineering at Dalian University of Technology has made a significant breakthrough. Their novel approach combines a non-photosynthetic bacterium with cadmium sulfide nanoparticles to create a biohybrid system that can produce ammonium from nitrate using sunlight. This innovation, published in the journal *Engineering* (translated from Chinese), could potentially reshape the agricultural and energy sectors by offering a greener alternative to the century-old Haber-Bosch process.
The Haber-Bosch process, which converts nitrogen gas into ammonia, is a cornerstone of modern agriculture, producing the fertilizers that feed the world. However, it comes at a substantial environmental cost, consuming vast amounts of energy and emitting significant greenhouse gases. Guo’s research presents a promising alternative by leveraging the power of artificial photosynthesis.
At the heart of this innovation is the bacterium *Shewanella oneidensis* MR-1, which is paired with cadmium sulfide nanoparticles. This biohybrid system uses photoexcited electrons to drive the reduction of nitrate to ammonium. The process achieves near-perfect nitrate reduction efficiency, with over 90% selectivity for ammonium production. The maximum instantaneous quantum efficiency recorded was an impressive 3.01% under light irradiation.
“The reverse metal-reducing pathway in *Shewanella oneidensis* MR-1 is crucial for transferring photoexcited electrons to intracellular compartments,” explains Guo. This pathway facilitates the conversion of nitrate to ammonium via the dissimilatory nitrate reduction to ammonium (DNRA) pathway, a process that could be harnessed for large-scale, sustainable ammonium production.
The implications for the energy and agricultural sectors are profound. By utilizing solar energy to drive the production of ammonium, this biohybrid system could significantly reduce the carbon footprint of fertilizer production. This aligns with the growing global demand for sustainable and eco-friendly industrial processes.
“Our study provides a facile strategy for light-driven ambient ammonium synthesis and solar-to-chemical conversion,” Guo adds. This breakthrough could pave the way for future developments in artificial photosynthesis, offering a scalable and sustainable solution for ammonium production.
As the world grapples with the challenges of climate change and the need for sustainable energy solutions, innovations like this biohybrid system offer a glimmer of hope. By combining the best of biological and technological advancements, researchers are edging closer to a future where industrial processes are not only efficient but also environmentally friendly. The research published in *Engineering* marks a significant step in this direction, highlighting the potential of biohybrid systems to revolutionize the energy and agricultural sectors.