LAUSR

l‐Fucose, as a monosaccharide in nature, plays a crucial role in bacteria colonization. Escherichia coli (E. coli), as a common microorganism in environment, utilize bacterial flagellar motor to drive the rotation of flagella, which is regulated by chemotactic signal transduction signals. Yet the effect of l‐fucose to bacterial motility remains unclear. The effect of l‐fucose on the swimming motility of bacteria was investigated from the level of single flagellar motor to individual cell and cell population by employing a bead assay, a high‐throughput 2D tracking assay and a high‐throughput dark‐field flicker microscopy. The results showed that the swimming motility of the bacteria cultured with l‐fucose was decreased, while the tumble frequency increased. Furthermore, the behavioral alterations of bacteria affected by l‐fucose were directly reveled by measuring the cell distribution of bacteria swimming near surfaces and bacterial surface adhesion, suggesting that l‐fucose promotes bacterial surface aggregation and surface adhesion. The effect of l‐fucose on bacterial swimming motility characterized in this study are consistent with the key role that l‐fucose plays in bacterial colonization.