Biofilms: Naturally Immobilized Microbial Cell Factories

Biocatalyst, including bacteria, fungi and their enzymes are an effective and environmentally preferred tools for industrial biotechnological applications, and for emerging wastewater treatment technologies. Due to low waste generation and energy requirements, biocatalyst-mediated processes have an edge over many established chemical processes and are also more economical. In most of the cases biocatalysts, especially whole cells need to be immobilized to make them reusable and cut down the downstream costs. Biofilms, which consists of surface-attached microbial cells, have natural immobilization due to the secretion of biopolymers by its own cells. Biofilms are identified as potential industrial workhorses for their sustainable production of chemicals, due to their high resistance to reactants and toxic chemicals, easy separation from the bulk liquid and long-sustaining enzymatic activity, which all facilitate continuous processing. Despite these favorable characteristics, utilizing biofilms as live biocatalysts has not yet broadly implemented concept in bioprocess development due to few bottlenecks. Of late, new prospective opportunities using these biofilm-based biocatalysts are showing an ascending application and seem to be feasible with the better understanding of mechanisms of biofilm biology. This chapter summarizes the recent developments in biofilm research with special emphasis on the advantages and disadvantages of biofilm-mediated processes for viable applications.