Extracellular electron transfer is the predominant electricity generation process in microbial fuel cells (MFCs). Our pervious study have proved that the anodic adsorption of rhamnolipid resulted in the Frumkin effect, which enhanced anodic microorganism attachment and accelerated anodic electron transfer. In this study, an in-depth research on the influence of rhamnolipid on functional genes of anodic biofilms metagenomes was carried out to explain its mechanism at the gene level. The result showed that the composition and distribution of functional genes in each dominant genus were different. The category of signal transduction mechanisms was the dominant function category in exoelectrogens, and its relative abundance in the metagenome significantly increased from 4.56 to 5.86% from rhamnolipid addition. Additionally, the metabolic pathway and electron flow analysis revealed that electron flows tend to choose direct electron transfer in the presence of rhamnolipids, and resulting in the increase of Coulombic efficiency from 19.10 ± 0.79% to 27.39 ± 1.07%.

细胞外电子转移是微生物燃料电池（MFC）中主要的发电过程。我们以前的研究已经证明鼠李糖脂的阳极吸附导致了Frumkin效应，从而增强了阳极微生物的附着并加速了阳极电子的转移。在这项研究中，鼠李糖脂对阳极生物膜元基因组功能基因的影响进行了深入研究，以从基因水平解释其机制。结果表明，每个显性属中功能基因的组成和分布是不同的。信号转导机制的类别是放电子中的主要功能类别，并且在鼠李糖脂添加后，其在元基因组中的相对丰度从4.56显着增加到5.86％。此外，