State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China.
Pipechina Institute of Science and Technology, No. 51 Jinguang Road, Guangyang District, Langfang 065000, China.
Curr Biol. 2024 May 20;34(10):2077-2084.e3. doi: 10.1016/j.cub.2024.04.005. Epub 2024 Apr 24.
Fungal biomineralization plays an important role in the biogeochemical cycling of metals in the environment and has been extensively explored for bioremediation and element biorecovery. However, the cellular and metabolic responses of fungi in the presence of toxic metals during biomineralization and their impact on organic matter transformations are unclear. This is an important question because co-contamination by toxic metals and organic pollutants is a common phenomenon in the natural environment. In this research, the biomineralization process and oxidative stress response of the geoactive soil fungus Aspergillus niger were investigated in the presence of toxic metals (Co, Cu, Mn, and Fe) and the azo dye orange II (AO II). We have found that the co-existence of toxic metals and AO II not only enhanced the fungal biomineralization of toxic metals but also accelerated the removal of AO II. We hypothesize that the fungus and in situ mycogenic biominerals (toxic metal oxalates) constituted a quasi-bioreactor, where the biominerals removed organic pollutants by catalyzing reactive oxygen species (ROS) generation resulting from oxidative stress. We have therefore demonstrated that a fungal/biomineral system can successfully achieve the goal of toxic metal immobilization and organic pollutant decomposition. Such findings inform the potential development of fungal-biomineral hybrid systems for mixed pollutant bioremediation as well as provide further understanding of fungal organic-inorganic pollutant transformations in the environment and their importance in biogeochemical cycles.
真菌生物矿化在环境中金属的生物地球化学循环中起着重要作用，并且已经被广泛探索用于生物修复和元素回收。然而，在生物矿化过程中有毒金属存在时真菌的细胞和代谢反应及其对有机质转化的影响尚不清楚。这是一个重要的问题，因为有毒金属和有机污染物的共同污染是自然环境中的常见现象。在这项研究中，研究了地生性土壤真菌黑曲霉在有毒金属（Co、Cu、Mn 和 Fe）和偶氮染料橙 II（AO II）存在下的生物矿化过程和氧化应激反应。我们发现，有毒金属和 AO II 的共存不仅增强了真菌对有毒金属的生物矿化作用，而且加速了 AO II 的去除。我们假设真菌和原位真菌生物矿化（有毒金属草酸盐）构成了一个准生物反应器，其中生物矿化通过催化氧化应激产生的活性氧物种（ROS）来去除有机污染物。因此，我们证明了真菌/生物矿化系统可以成功实现固定有毒金属和分解有机污染物的目标。这些发现为混合污染物生物修复中真菌-生物矿化混合系统的潜在发展提供了信息，并进一步了解了真菌在环境中的有机-无机污染物转化及其在生物地球化学循环中的重要性。
