School of Ecology and Environment, Beijing Technology and Business University, Beijing 100048, China.
State Environmental Protection Key Laboratory of Food Chain Pollution Control, Beijing Technology and Business University, Beijing 100048, China.
Int J Environ Res Public Health. 2022 Apr 18;19(8):4923. doi: 10.3390/ijerph19084923.
The rapid development of biogas plants in China has generated large quantities of digestate. The disparity between the continuity of biogas plant operation and the seasonality of digestate utilization has led to the need to store digestate. Therefore, untargeted profiling of bioactive compounds in the digestate stored under aerobic and anaerobic conditions was performed. The antioxidant and antifungal activity of digestate stored under varying conditions was likewise assessed. The results delineated that digestate storage under varying conditions brought about the degradation of organic acids, alkenes, aldehydes, alcohols, ketones, ethers, amino acids and their derivatives, and esters, leading to the stabilization of digestate components. Together, these new data revealed that digestate storage for up to 20 days under aerobic conditions promotes glycine, serine, and threonine degradation pathways and enhances biotin and vitamins production. In contrast, anaerobic storage enhances the taurine and hypotaurine metabolic pathways and increases the derivation of antimicrobial substances, such as indole alkaloids. Moreover, digestate storage under anaerobic conditions promotes antioxidant and antifungal activity more than storage under aerobic conditions. These findings can contribute to the future development of high-value agricultural products from digestate and the sustainability of biogas plants. Further studies are required for the untargeted metabolomic of digestate under storage to explore the underlying mechanisms of promoting disease resistance by the digestate upon land application.
中国沼气工程的快速发展产生了大量的沼渣。由于沼气工程运行的连续性和沼渣利用的季节性之间存在差异，因此需要对沼渣进行储存。因此，本研究对好氧和厌氧条件下储存的沼渣中的生物活性化合物进行了非靶向分析，并评估了储存条件下沼渣的抗氧化和抗真菌活性。结果表明，在不同条件下储存沼渣会导致有机酸、烯烃、醛类、醇类、酮类、醚类、氨基酸及其衍生物和酯类等有机化合物的降解，从而稳定沼渣成分。这些新数据表明，在好氧条件下储存 20 天以内可以促进甘氨酸、丝氨酸和苏氨酸的降解途径，并提高生物素和维生素的产量。相比之下，厌氧储存会增强牛磺酸和次牛磺酸的代谢途径，并增加抗菌物质（如吲哚生物碱）的衍生。此外，厌氧储存比好氧储存更能促进沼渣的抗氧化和抗真菌活性。这些发现有助于未来从沼渣中开发高价值的农业产品，并提高沼气工程的可持续性。需要进一步研究储存条件下沼渣的非靶向代谢组学，以探索沼渣在土地应用中提高抗病性的潜在机制。
