In a recent paper that was published by the Gourse Lab at the University of Wisconsin-Madison,discusses the biofilm matrix gene expression in Bacillus subtilis. A biofilm matrix is made up of multicellular communities that stick to many types of surfaces in different environments, and the production of extracellular matrix enables the formation of these communities. Once the biofilm matrix forms, the flagella motility is inhibited by the organism. On a molecular level, the eps and tapA-sipW-tasA are two essential operons that enable the production of the biofilm matrix. In addition to the eps and tapA-sipW-tasA operons, SinR and RemA are two DNA-binding proteins that play vital roles in the regulation as well. The Gourse Lab suggested that the DNA-binding protein SinR negatively regulates the eps operon expression by blocking RemA binding. In addition, SinR functions as an anti-activator to the P_eps promoter.

On the other hand, the DNA-binding protein RemA activates the activity of the operons by binding to various sites on the promoters. Once activated, the inhibition of flagellar motility occurs simultaneously with biofilm formation, and it has been hypothesized that the process occurs in order to enhance the stabilization of the formation of the cluster. Cells that have sinR gene mutations are not motile due to the constitutive expression of EPS synthesis. The slrR gene encodes SlR, which is a secondary SinR antagonist that stimulates the cells even further in biofilm formation. The research shows that SinR inihibits the eps operon by competing with RemA for binding that deactivates the function. With the deletion of RemA binding sites upstream of P_eps promoter, it would prevent the formation of biofilm. In conclusion, the activation of biofilm matrix genes in B. subtilis requires the combination of at least two signals that include SinR and RemA. Understanding the factors in the biofilm formation could advance new techniques in ridding these structures in the industrial and clinical settings.