Photochemical reactions that widely occur in aquatic environments play important roles in carbon fate (e.g., carbon conversion and storage from organic matter) in ecosystems. Aquatic microbes and natural minerals further regulate carbon fate, but the processes and mechanisms remain largely unknown. Herein, the interaction between Escherichia coli and pyrite and its influence on the fate of carbon in water were investigated at the microscopic scale and molecular level. The results showed that saccharides and phenolic compounds in microbial extracellular polymeric substances helped remove pyrite surface oxides via electron transfer. After the removal of surface oxides on pyrite, the photochemical properties under visible-light irradiation were significantly decreased, such as reactive oxygen species and electron transfer capacity. Unlike the well-accepted theory of minerals protecting organic matter in the soil, the organic matter adsorbed on minerals preferred degradation due to the enhanced photochemical reactions in water. In contrast, the minerals transformed by microbes suppressed the decomposition of organic matter due to the passivation of the chemical structure and activity. These results highlight the significance of mineral chemical activity on organic matter regulated by microbes and provide insights into organic matter conversion in water.

广泛发生在水生环境中的光化学反应在生态系统中的碳归宿（例如，有机物质中的碳转化和储存）中发挥着重要作用。水生微生物和天然矿物质进一步调节碳的命运，但过程和机制仍然很大程度上未知。在此，在微观尺度和分子水平上研究了大肠杆菌和黄铁矿之间的相互作用及其对水中碳去向的影响。结果表明，微生物胞外聚合物中的糖类和酚类化合物有助于去除黄铁矿表面的氧化物。电子转移。去除黄铁矿表面氧化物后，可见光照射下的活性氧和电子转移能力等光化学性质显着降低。与广为接受的矿物质保护土壤中有机物的理论不同，由于水中的光化学反应增强，吸附在矿物质上的有机物更倾向于降解。相比之下，微生物转化的矿物质由于化学结构和活性的钝化，抑制了有机物的分解。这些结果突出了矿物化学活性对微生物调节的有机物的重要性，并为水中有机物的转化提供了见解。