Abstract:Flagella are slender and curved protein filaments associated with the surface of many bacteria. As the motility ‘organ’ of bacteria, flagellum is one of structures that have been most extensively studied in microbiology. Through flagellar movement, bacteria can better adapt to their habitat or escape from unfavorable environments. In addition, flagellar plays an important role in the colonization of host surfaces by harmful or beneficial bacteria, and in their biofilm formation and other tight interaction with their hosts. Bacillus is ubiquitous in the nature containing many species and strains with great value in industrial, agricultural and medicinal applications. In this work, the research progress on the flagella and motility-related properties of Bacillus is reviewed. Firstly, we introduced the structural composition, assembly process, and expression regulation of synthetic genes of Bacillus flagella. Secondly, relationships and the underlying molecular mechanisms of Bacillus flagella motility and its motility-related characteristics of including the biofilm formation and dispersal, sporulation, competence, and production of γ-polyglutamic acid and antibiotics is discussed. This review aims at providing comprehensive knowledge and theoretical guidance for related studies in this field.