| Autor: |
Tang Y; Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon 999077, Hong Kong, China.; School of Civil and Environmental Engineering, Cornell University, Ithaca, New York 14850, United States., Khan E; Department of Civil and Environmental Engineering and Construction, University of Nevada, Las Vegas, Nevada 89154, United States., Tsang DCW; Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, 999077, Hong Kong, China. |
| Abstrakt: |
This study proposes a novel strategy that utilizes biochar (BC) during anaerobic fermentation (AF) to generate amino acids (AAs) toward nitrogen upcycling. The BC, pyrolyzed at 800 °C (BC800) to enhance graphite structures and electron-accepting sites, effectively addresses issues related to biosynthetic reducing power nicotinamide adenine dinucleotide phosphate insufficiency by altering cellular conditions and alleviates feedback inhibition through the immobilization of end products. This process establishes unique microbial signaling and energy networks, with Escherichia coli becoming dominant in the biofilm. The conversion rate of ammonia-N to AAs-N within the biofilm reached 67.4% in BC800-AF, which was significantly higher compared to the levels in other AF reactors with BC pyrolyzed at 600 and 400 °C (45.9 and 22.5%, respectively), as well as a control AF reactor (<5%). Furthermore, in BC800-AF, the aromatic AAs (Aro-AAs) were as high as 70.8% of the AAs within the biofilm. The activities of key enzymes for Aro-AAs biosynthesis uniquely positively correlated with the electron-accepting capacity on BC800 ( R 2 ≥ 0.95). These findings hold promise for transforming existing AF reactors into factories that produce BC-based AAs, providing a more sustainable fertilizing agent than chemical fertilizers. |
