Microbial carriers may co-transport polycyclic aromatic hydrocarbons (PAHs), but lack substantial experimental evidence. Cable bacteria use gliding or twitching motility to access sulfide; hence, they could be important microbial carriers in co-transporting PAHs from the sediment-water interface into suboxic zones. In this study, the effect of cable bacteria on pyrene migration was investigated by connecting or blocking the paths of cable bacteria to the suboxic zones. The results showed that downward migration of pyrene in the connecting groups were significantly higher (17.3–49.2%, p < 0.01) than those in the control groups. Meanwhile, significant downward migration of microbial communities in the connecting groups were also observed, including abundant filamentous-motile microorganisms, especially cable bacteria. The adsorption of surrounding particles by cable bacteria were morphologically evidenced. The biomechanical model based on the Peclet number indicated that filamentous-motile microorganisms demonstrated stronger adsorption ability for pyrene than other microorganisms. Supposedly, the downward migration of microbial communities, especially cable bacteria, significantly enhanced pyrene migration, thus influencing the distribution and ecological risk of pyrene in sediments. This study provides new insights into the important roles of motile microorganisms in the migration of PAHs in sediments, shedding lights on guidance for ecological risk assessment of PAHs.

微生物载体可以共同运输多环芳烃（PAHs），但缺乏大量的实验证据。电缆细菌利用滑行或抽搐运动来获取硫化物；因此，它们可能是重要的微生物载体，将多环芳烃从沉积物-水界面共同运输到低氧区。在这项研究中，通过连接或阻断电缆细菌通往低氧区的路径，研究了电缆细菌对芘迁移的影响。结果表明，连接组中芘的向下迁移显着更高（17.3-49.2％，p < 0.01) 高于对照组。同时，还观察到连接组中的微生物群落显着向下迁移，其中包括大量的丝状运动微生物，尤其是电缆细菌。形态学上证明了电缆细菌对周围颗粒的吸附。基于Peclet数的生物力学模型表明，丝状运动微生物对芘的吸附能力强于其他微生物。据推测，微生物群落，尤其是电缆细菌的向下迁移显着增强了芘的迁移，从而影响了芘在沉积物中的分布和生态风险。这项研究为运动微生物在沉积物中 PAHs 迁移中的重要作用提供了新的见解，