Dispersal and inhibitory roles of mannose, 2-deoxy-d-glucose and N-acetylgalactosaminidase on the biofilm of Desulfovibrio vulgaris

Biofilms of sulfate-reducing bacteria (SRB) are often the major cause of microbiologically influenced corrosion. The representative SRB Desulfovibrio vulgaris has previously been shown to have a biofilm that consists primarily of protein. In this study, by utilizing lectin staining, we identified that the biofilm of D. vulgaris also consists of the matrix components mannose, fucose and N-acetylgalactosamine (GalNAc), with mannose predominating. Based on these results, we found that the addition of mannose and the nonmetabolizable mannose analog 2-deoxy-d-glucose inhibits the biofilm formation of D. vulgaris as well as that of D. desulfuricans; both compounds also dispersed the SRB biofilms. In addition, the enzyme N-acetylgalactosaminidase, which degrades GalNAc, was effective in dispersing D. vulgaris biofilms. Therefore, by determining composition of the SRB biofilm, effective biofilm control methods may be devised.